michigan state universitywhirlpool is a company that has always strived for innovation and...

Whirlpool Dispenser Cup Challenge

Michigan State University

Senior Design - ECE 480 - Team Eight

Spring 2015

Project Sponsor: Whirlpool Corporation

Project Facilitator: Dean Aslam

Team Members: Daniel Sun

Connor Grossman

Daniel Gomez

Gao Xin

Hongyi Shen

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Executive Summary

The new Whirlpool dispenser cup does not only differentiate between powder

and liquid detergent as well as liquid bleach and fabric softener, it also adds a new user

interface via LEDs. This makes the system not only user-friendly, but efficient. Telling

the difference in the cup’s contents allows the system to optimize energy, and water

usage. Our team, ECE 480 Design Team Eight will provide a prototype of this dispenser

cup design. The system interacts with three sensors, one for each cup, it is robust,

accurate and resistant to moisture, ambient light and vibration originating from the

washing process. The final manufacturing cost of the dispenser cup is less than $4.00.

Whirlpool is a company that has always strived for innovation and sustainability.

With the interaction between Whirlpool, Michigan State University and ECE 480 Design

Team Eight, Whirlpool continues to show that its primary concern is their customers, not

only will they provide a quality product, but they will make this product easy to use while

also being energy and water efficient.

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Acknowledgements

On behalf of ECE 480 Design Team Eight, we would like to thank the following people

that have helped us in succeeding to achieve our goals for this project:

Our sponsors from Whirlpool Corporation, Jason Savage and Jeff Landrey for their

guidance, advice and support in the learning and development of our project as well as

the industry

Our facilitator, Dr. Dean Aslam, for his guidance, critique and creativeness that has

solved many issues that we have come across

MSU ECE Technical Services: Mr. Brian Wright and Mrs. Roxanne Peacock, for

supplying and ordering parts along with providing testing equipment

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Table of Contents:

Chapter 1 - Introduction ……………………………………………………………………..6 1.1 Whirlpool Project - Dispenser Cup ……………………………………………6

1.2 Whirlpool Corporation ………………………………………………………….6

1.3 Advantages of Dispenser Cup ………………………………………………...7

Chapter 2 - Exploring solutions and Selecting one …………………………………….8

2.1 Analysis with FAST Diagram ………………………………………………….8

2.2 Analysis with House of Quality ……………………………………………….9

2.3 LED/Sensor/Cup Design ……………………………………………………..12

2.4 Budget Planning and Final Cost per Unit …………………………………..13

2.5 Project Timeline: Gantt chart ………………………………………………...15

Chapter 3 - Technical Description ……………………………………………………….17

3.1 Light Selection ………………………………………………………………..17

3.1.1 Red Green B lue (RGB) LED …………………………………………18

3.1.2 Super B r igh t Red LED ………………………………………………..19

3.2 Microcontroller Selection ……………………………………………………..20

3.2.1 E Z 4 3 0 - R F 2 5 0 0 … … … … … … … … … … … … … … … … … … … … … . . 2 0

3.2.2 CC2500 Transce iver w i th MSP430 …………………………………21

3.2.3 A t m e g a 1 2 8 R F A 1 m i c r o c o n t r o l l e r … … … … … … … … … … … 2 2

3.2.4 A t m e l S t u d i o … … … … … … … … … … … … … … … … … … … … … … . . . 2 3

3.3 Dispenser Cup 3D Model …………………………………………………….20

3.3.1 S i e m e n s N X 9 . 0 … … … … … … … … … … … … … … … … … … … … … . 2 4

3.3 .2 Test ing Dispenser Cup Model ……………………………………….24

3.3.3 First Design Prototype ………………………………………………………………..30

3.3.4 F ina l 3D Cup Des ign ………………………………………………….34

3.4 Sensor Selection ……………………………………………………………...38

3.4.1 E lec t r i ca l Opt i ca l Sensor ……………………………………………..38

3.4.2 C h e m i r e s i s t o r s … … … … … … … … … … … … … … … … … … … … … . . . 3 9

3.4.3 P h o t o r es i s t o r s … … … … … … … … … … … … … … … … … … … … … … 4 1

3.5 Power Supply Selection ………………………………………………………44

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3.5.1 So lar Ce l l and Rechargeab le Bat te ry ……………………………..44

3.6 Data Communication …………………………………………………………45

3.6.1 U S B … … … … … … … … … … … … … … … … … … … … … … … … … … . 4 5

3.6.2 W i - F i … … … … … … … … … … … … … … … … … … … … … … … … … … . . . 4 6

Chapter 4 - Data Tests ………………………………………………………………………47

4.1 Sensor Testing ………………………………………………………………...47

4.2 Photoresistor Testing …………………………………………………………47

4.3 LED Color Testing …………………………………………………………..48

Chapter 5 - Dispenser Cup: Final Summary …………………………………………....49

5.1 Summary ……………………………………………………………………….49

5.2 Lessons Learned ……………………………………………………………..50

5.3 Further Improvements ………………………………………………………..51

Chapter 6 - Appendix 1 …………………………………………………………………......53

6.1 Technical and Non-Technical Roles ………………………………………..53

6.2 Daniel Sun ……………………………………………………………………..54

6.3 Connor Grossman …………………………………………………………….54

6.4 Daniel Gomez ………………………………………………………………....55

6.5 Hong Yi Shen ………………………………………………………………..55

6.6 Gao Xin ……………………………………………………………………....56

Chapter 7 - Appendix 2 …………………………………………………………………….57

7.1 References …………………………………………………………………..57

Chapter 8 - Appendix 3 ……………………………………………………………………..58

8.1 Parts Identification …………………………………………………………..58

8.2 Programming Screen ……………………………………………………....63

8.3 Testing the Code …………………………………………………………….65

8.4 Circuit Calculations ………………………………………………………..105

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Chapter 1 - Introduction

1.1 Whirlpool Project - Dispenser Cup

Dispenser Cup Contents Detection is the project that Whirlpool has given to

design team eight. Through this project, the team needs to create a dispenser cup that

is able to power itself and also communicate with the appliance without any contact

pads or harnesses. The cup must also support six LEDS, a microcontroller, dispenser

cup sensors and any communication device that the team uses. The cup also has to be

robust to high humidity, temperature (99% humidity with condescension) and vibration.

The entire system should not cost over $4 in manufacturing cost. These are the

requirements proposed by Whirlpool.

1.2 Whirlpool Corporation

Whirlpool Corporation is one of the largest washing machine manufacturers. It’s

headquartered is in Benton Charter which is a township in Michigan. The Company

was founded on November 11, 1911. At the very beginning, it was a small company

that produced electric, motor driven, wringer washers. With the science and technology

developing rapidly, most families chose to use a washing machine at home instead of

doing laundry outside washing by hand or driving to the laundromat. So the rigid

demand of having a household washing machine increased rapidly. Whirlpool growing

fast and becoming one of Fortune 500 company, having an annual revenue of about

19 billion dollars. They have more than 70 manufacturing and technology research

centers in the world. However a new problem also came up, which is how to use the

least energy to wash the clothes clean. Being energy efficient and to be

environmentally friendly are two big problems for the manufacturer. In addition, with

the fossil energy being scarce, the government and many environmental protection

organizations are pressing this issue. Energy Star is an international standard for

energy efficient consumer, it was created in 1992 by the Environmental Protection

Agency and the Department of Energy. It aims to encourage the manufacturer to

design the most energy efficient product. We can see the Energy Star label on most of

whirlpool products on the market.The label shows how much energy and money it can

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save a customer every year. For the customer, they take this into their consideration

when they choose the product. Now, many companies like whirlpool are willing to fund

the research to find a more economically feasible way to reduce energy cost.

1.3 Advantages of Dispenser Cup

Whirlpool has been known for being a energy efficient company. There are many

aspects of the dispenser cup that will hold up to their value. When there is no cycle

selected the dispenser cup system will go into the low power state. The low power state

will be more energy efficient and environmentally friendly. With the implementation of

content sensor in the dispenser cups, there will be no residue within the cup and that is

another aspect of saving resources. The dispenser cup will also tell user the amount of

detergent, softener, and bleach to pour in. This will let the user know that they are not

over pouring or under pouring the materials. These aspects of the dispenser cups is

environmentally friendly and energy efficient. This is the reason that dispenser cups are

being invested into and hopefully used heavily in the next couple of years due to the

growing market of household appliances.

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Chapter 2 - Exploring solutions and Selecting One

2.1 FAST Diagram Analysis with Fast Diagram The Function Analysis System Technique (FAST) Diagram shown in figure 2.1

demonstrates how design team eight initiated its system for the whirlpool team. On the

left is the goal of this project which is to start a cycle of a washing machine. The way it

gets there is starting from the far right. The user selects a cycle on the washing machine

which then is transmitted wirelessly via microcontroller to the other board. After the

microcontroller receives the information the LEDS should light up on the cup indicating

which cup should be filled. The user then will add materials to the cup which starts the

sensing cycle. The cup will sense whether the material that is poured in was indeed the

material that is suppose to be poured in. If the material that is poured in is correct, the

LED will shine up as green, if it is shines up as red it means that the user has poured in

the wrong content in the cup. Assuming the right content was poured in, the dispenser

cup system will send back a signal to the main washing machine system which allows

the cycle to be started.

Figure 2.1 FAST Diagram of System Goals

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Team eight uses mainly three components for this project: mechanical, electrical

and software. The mechanical devices includes the dispenser cup itself and all the other

materials that the team used for testing. The electrical devices includes the

microcontrollers, LEDs and the photoresistors. The software devices include the

programming of the microcontroller and an interface which user can select certain

cycles to test the program. These are the concepts that team eight is able to prove at

the end of this project.

2.2 Analysis with House of Quality

By creating a house of quality, our team was able to prioritize the customers

wants, which then help us focus on what mattered most to the costumers. Our house of

quality can be seen in figure 2.2.2 and the legend for the house of quality is seen in

figure 2.2.1.

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Figure 2.2.1 House of quality legend

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Figure 2.2.2 House of quality analysis

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The house of quality analysis has prioritized our customer wants in this order (highest to

lowest):

● Accurate Sensor

○ Detecting liquid detergent

○ Detecting powered detergent

○ Detecting Fabric Softener

● Low Cost System

● Time for Wireless Communication

● Robust and Compact Size

2.3 LED/Sensor/Cup Design

Design team eight has designed the cup to be robust to vibrations and

temperatures and have met the requirements for dispenser cup. The team decided to

put three LEDs on the top layer of the dispenser cup to notify the user that which

content they should be pouring in. The other three LEDs will be implanted within the

dispenser cup and will only light up when materials have been poured in. These LEDs

will serve as a light source for the photoresistor to read. The team is basing this

technology on the thought that the LEDs light will emit different strengths through the

different materials. For example, more light will go through the detergent instead of the

softener. Therefore having difference in those values would help determine what are the

materials that were poured in. After the dispenser cup determines that it is the right

material that has been poured in, then the light would shut off and the cycle would

begin. Therefore with three different cups there will be three different photoresistors on

the cap of each cup. The team has selected to place the LED on the bottom of the cup

and the photoresistor on top implanted in the cap. This is because the team is scared

that photoresistors are not chemical proof and therefore cannot be submerged within

materials. We would want to, however, have them on two sides of the cup to enable

correct readings regardless of the amount of material the user has poured in.

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2.4 Budget Planning and Final Cost Per Unit At the beginning of this project, the group was handed a $500 budget to spend

on any resources that the group might use to finish this project. The group mostly spent

the budget on purchasing washing chemicals such as Detergents, Softener and Bleach.

Other costs included sensors and different type of LEDS. The most important purchase

was to buy the microcontroller that could perform the wireless communications. Good

budget planning was essential to giving the team room to invest and test different

methods of finishing this project. This team was still able to finish the project under the

$500 budget and still have leftover. The expenses of this team is fully detailed in the

below table.

Components Quantity Cost Shipping Total

20 Pcs 50-100K ohm

Photoresistor

1 $4.22 $0.0 $4.22

Solar Cell

1 $6.95 $0.0 $6.95

Super Bright Red 5mm LED

4000

1 $2.98 $5.95 $8.93

RGB LED, 50 pack

1 $9.95 $0.0 $9.95

TI eZ430-RF2500

1 $116.28 $0.0 $116.28

Tide original HE Detergent

1 $9.94 $0.0 $9.94

Downy Ultra liquid fabric

softener

1 $7.98 $0.0 $7.98

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Tide Plus Bleach Alternative

1 $13.99 $5.99 $19.98

TI CC2500

2 $4.03 $4.09 $12.14

Energizer Power Plus NiMH

AA Rechargeable batteries

1 $12.19 $0.0 $12.19

DECS 3D print of a battery

case

1 $1.0 $0.0 $1.0

3D print Cup

1 $23.79 $0.0 $23.79

3D print Final Dispenser Cup 1 $40.00 $0.0 $40.00

SparkFun ATmega128RFA1

micro-controller

2 $171.780 $7.98 $179.76

Total $453.11

Table 2.4 Project Cost

Team eight has demonstrated the costs it takes to accomplish the goal. The

team does suggest that this cost is due to purchasing pieces with low quantity. The

team do believe if these materials were bought in bulk the cost would go down

significantly. The estimated manufacturing should be relatively cheap. The cost will

heavily depend on what material the cup will be made out of and which microcontroller

is used. Photoresistors and LEDs could be purchased with a very cheap price when

they come in a bulk.

With the bulk price, the team believes that the cost can make it to under $4.

Please look at Figure 2.4 for more details.

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Figure 2.4 Manufacturing Cost of Dispenser Cup

2.5 Project Timeline: Gantt chart Figure 2.5 is the Gantt chart for design team eight. Team eight realizes that being

on time is just as important as being under budget and being resourceful. From this

gantt chart the team wanted to first define the project task. From there on the team

moved on to sensor testing, software resource decision, power supply design, hardware

development, software development, and finally full dispenser cup emulator which

combines everything together. The Gantt chart listed dates on when a goal would be

started and when it should be accomplished. The design team followed this schedule

strictly and had all these tasks done on time. There are more detail tasks shown in

Figure 2.5.

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Figure 2.5 Team Eight Gantt Chart

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Chapter 3 - Technical Description

3.1 Light Selection

One half of the light sensor is the light source, in our case the light source is a

light emitting diode (LED). A LED is a two lead semiconductor light source consisting of

a P-N junction that only lets current flow in one direction. Since current can only flow in

one direction it has the ability to change alternating current into direct current. The light

is created by the movement of electrons across a semiconductor by a phenomenon

called electroluminescence. The light is electromagnetic radiation as the electrons flow

through the semiconductor; this electromagnetic radiation is what the human eye picks

up as visible light. The electromagnetic radiation is in the form of photons.

When dealing with a light sensor, the selection of the light is a very important part

of the design. The intensity and the color of the light have extreme effects on the photo

resistor. These effects are due to cadmium sulfide which is the photoconductive

material in the photo resistor. Cadmium sulfide is more conductive with increased

intensity of the light and more sensitive to certain colors of light (figure 3.1.1). These

factors all contribute to the accuracy of our sensor making it extremely important to

choose the best intensity and color for our design.

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Figure 3.1.1 Color Sensitivity of Cadmium Sulfide

3.1.1 Red Green Blue (RGB) LED

This type of LED is a little different than a tradition LED. It contains a total of four

pins (figure 3.1.1.1). The colors (red, green and blue) each have their own cathode pin

and they all share a common anode. This type of LED was ideal for testing different

colors and how they affected the reading from our photoresistor. Beside testing the

primary colors red, greens and blue, they could also mixed to provide different colors

across a wide range of different brightnesses. The precision to produce an accurate

color really helped the team to determine which color was optimum to determine

between fabric softener, liquid and powder detergent.

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Figure 3.1.1.1 RGB LED Pins

3.1.2 Super Bright LED

The super bright LED emitted a red light which in the case of emitting light

through a material has some beneficial properties. Red light has a wavelength around

650 nm making it the longest wavelength among colors in the visible light spectrum.

This long wavelength gives it the ability to move quicker through objects, in turn, making

it bend less sharply. The combination of the LED and photoresistor are both

inexpensive, durable and energy efficient making it ideal for our project.

Even though this seems like the ideal LED for our project some of these

properties actually worked against team eight. The illumination characteristics of our

photoresistor says that the resistance decreases rapidly as light intensity increases

(figure 3.1.2.1). Therefore, when nothing is present is when the photoresistor will be at

its lowest resistance producing a lower voltage then when materials are poured into the

cup. The extreme brightness of the LED would emit strongly through the opaque liquids

giving the voltages for liquid detergent and fabric softener very similar readings making

it more difficult to program the microcontroller to distinguish between the different

materials.

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Figure 3.1.2.1 Intensity vs. Resistance for CdS photocell

3.2 Microcontroller Selection

At the beginning of this project, the selection of the microcontroller is an big issue

for the team. The project requirements insisted on having wireless communication and

the team proposes that they either uses a microcontroller along with a transceiver or a

built in wireless function within microcontrollers. Below the team explores the

possibilities and the final decision that has been made by the team eight.

3.2.1 EZ430-RF2500

One of the possibility that the team proposes is using the EZ430-RF2500

microcontroller. The purchase of EZ430-RF2500 comes with two boards and a tutorial

manual. These two boards are identical and have 20 pins and a microcontroller. It has

built in wireless communication which allows one board to communicate with the other.

If one board is the main inserted as the main system, the other board will be placed

within our circuit. This microcontroller is selected due to the wireless communication

built within. Although this microcontroller is costly, the team decided to use it for the

testing stage of the project. With this microcontroller the team is able to light up the

LEDS for the cup with the three different colors. However the main issue with this

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microcontroller that it is hard to program and very expensive. Therefore the team began

to explore other options that might be a better fit to this project.

Figure 3.2.1 EZ430-RF2500 Microcontroller

3.2.2 CC2500 Transceiver with MSP430

Another possibility that team eight proposed was using any MSP430

microcontroller tagged along with CC2500 Transceiver. The CC2500 transceiver acts as

a wireless communication device which is pivotal to the project requirements. MSP430

microcontrollers have been used in the ECE480 lab courses and is relatively easy to

program. The team is able to program MSP430G2553 to light up the LEDS however the

most important concept of wireless communication is not implemented. That is the

reason the team suggested to combine the MSP430’s with CC2500. CC2500 is a

transceiver that costs $4.03 each. A transceiver could both transmit data and receive

data. Therefore, if the team programed the transceiver along with the CC2500 it could

lower the manufacturing price and also achieve the project goal. Figure 3.2.2.1 and

Figure 3.2.2.2 are photos of CC2500 transceiver and MSP430G2553.

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Figure 3.2.2.1/2 MSP430G2553 Microcontroller (1) along with CC2500 Transceiver (2)

3.2.3 Atmega 128RFA1 microcontroller Due to the limitation of MSP430, the team has a back up plan which is using 2 of

Atmega 128RFA1.

Atmega 128RFA1 is an AVR microcontroller with the wireless transceiver

embedded. One of microcontroller will be embedded within an usb port to connected

with computer or ALU (figure 3.2.3.1). Another one will be embedded with the dispenser

cup (figure 3.2.3.2). The detail of whole communication system and control system will

be introduced at section 3.6.

Figure 3.2.3.1

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Figure 3.2.3.2

3.2.4 Atmel Studio

Atmel Studio is a software developed by Atmel. It can support most of

microcontroller of Atmel products in both C and C++. As it said on its website “Atmel®

Studio 6 is the integrated development platform (IDP) for developing and debugging

Atmel ARM® Cortex®-M and Atmel AVR® microcontroller (MCU) based applications.

The Atmel Studio 6 IDP gives you a seamless and easy-to-use environment to write,

build and debug your applications written in C/C++ or assembly code. Atmel Studio 6 is

free of charge and is integrated with the Atmel Software Framework (ASF)—a large

library of free source code with 1,600 ARM and AVR project examples. ASF

strengthens the IDP by providing, in the same environment, access to ready-to-use

code that minimizes much of the low-level design required for projects. Use the IDP for

our wide variety of AVR and ARM Cortex-M processor-based MCUs, including our

broadened portfolio of Atmel SAM3 ARM Cortex-M3 and M4 Flash devices.” Since our

Atmega 128rfa1 is one of their AVR micro-controller and the software is free, it is the

best software to do the coding and debugging.

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3.3 Dispenser Cup 3D Model In order to meet all the requirements from the customer, the dispenser cup has to

be able to communicate with the washer wirelessly and the LEDs has to be used to

assist the user to employ the dispenser cup. In addition, the dispenser is removeable

and can be reassembled after cleansing. To use the dispenser cup model to test for the

project, a cup lid will be needed to insert the photoresistor. The bottom center of each

cup has a hole for inserting LED. After pouring material into the cup, the voltage across

the photoresistor can be measured by closing the cup lid and connecting the

photoresistor to the circuit.

3.3.1 Siemens NX 9.0

Siemens NX 9.0 has been to used to design the dispenser cup and all other

parts. Based on Ms. Xin’s previous experience on using Siemens NX 9.0 to design 3D

print model, she used the NX software to design the dispenser cup model, testing cup

and the battery case for the group.

3.3.2 Testing Dispenser Cup Model Before printing out the model, a testing dispenser cup had been designed, which

contains one cup and one lid. In the center of the cup, LED can be inserted and

photoresistor can be inserted in the center of the lid.

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Figure 3.3.2-1 Testing Cup

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Figure 3.3.2-2 Testing Cup

Figure 3.3.2-3 Testing Cup Lid

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Figure 3.3.2-4 Top View of the Testing Cup

Figure 3.3.2-5 Isometric View of the Testing Cup

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Figure 3.3.2-6 Bottom View of the Testing Cup

Figure 3.3.2-7 Top View of the Lid

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Figure 3.3.2-8 Isometric View of the Lid

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3.3.3 First Design Prototype

The initial design of the dispenser cup has been designed to have three layers

with different functions, which can be assembled together and compose the dispenser

cup as a whole.

Figure 3.3.2-9 Assembled Dispenser Cup

In the first layer, there are three cups for detergent, bleach and softener

respectively. Also, there are three LEDs besides each cup. The application of the LEDs

is to tell the customer which cup needs to be filled and what should be put in the cup.

For example, when the detergent cup needs to be filled, the LED besides the cup will

turn to blue. When the cup is filled with the correct material and amount, the LED will

turn to green, otherwise the LED will be red.

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Figure 3.3.2-10 First Layer of the Dispenser Cup

In order to decrease the waste of detergent/bleach/softener, a unflat cup bottom

has been designed as the second layer.

Figure 3.3.2-11 Top View of the Second Layer of the Dispenser Cup

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Figure 3.3.2-12 Bottom View of the Second Layer of the Dispenser Cup

The bottom layer is to store the microcontroller, battery and other circuits. There

is also a common path for detergent/bleach/softener to go through to main part of the

washer.

To stabilize the dispenser cup, bars have been design in the second and bottom

layer. There are rectangular shaped bar holes at the bottom of the first and second layer

for bars to insert in.

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Figure 3.3.2-13 Top View of the Bottom Layer of the Dispenser Cup

The storage place is to store the microcontroller, power supply circuit and

battery. The LEDs of the first layer will be directly connected to the circuit from the

bottom layer. To keep the electrical circuit and microcontroller out of water, the storage

place and the detergent/bleach/softener path has been separated.

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Figure 3.3.2-14 Side View of the Bottom Layer of the Dispenser Cup

3.3.4 Final 3D Cup Design

However, based on the available budget of the group, the cost for printing out the

dispenser cup as designed as above is not applicable. After meeting with the Whirlpool

Co., a new dispenser cup needs to be designed, that no storage place for the circuit will

be needed since the cup is only a prototype. To decrease the cost for printing, different

layers needs to be eliminated and only the first layer was remained.

The modified cup only has two parts: cup and lid. There are three cups for

detergent, softener and bleach. Also, three LEDs have been added besides each cup.

In the bottom center of each cup, there is a hole that LED can be inserted, which will be

used as part of the testing procedure.

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Figure 3.3.4-1 Final Design of the Dispenser Cup

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Figure 3.3.4-2 Top View of the Modified Dispenser Cup

As for the lid, there are three holes for photo resistors to insert in to measure the

voltage across it when the LED has been turned on.

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Figure 3.3.4-3 Final Design Cup Lid

Figure 3.3.4-3 Isometric View of the Modified Dispenser Cup Lid

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3.4 Sensor Selection

The most feasible and effective way to detect contents in a dispenser cup has

been deemed to be a light sensor, with the light source at the bottom of the cup and a

light detecting source at the top. When emitting a light through a liquid or powder

detergent it will cause a change in the intensity of the light, which can be detected and

therefore tell the washing machine that the dispenser cup is filled. Not only is the design

of a light sensor simple but it can be very reliable and accurate for the needs of this

project. With the intensity of the light changing once contents are added to the cup, the

light sensor will cause a change in the voltage at the load. This change in voltage was

noticeable through testing, which makes the integration of a microcontroller to sense

this change possible. The design of a light sensor can also be used in the rough

conditions (vibrations and temperatures) of the washing machine which is a key factor in

choosing this route.

This, however, was not the only option that we explored. Through research and

advice there are multiple ways that fabric softener, liquid and powder detergent

effectively detected.

3.4.2 Electro-optic Sensor

The basic principle behind an electro-optic sensor is to take light and turn it into

readable data. The data this sensor is measuring is the quantity or intensity of light.

Many common uses for these are lamps that can turn on and off depending on the

amount of light, position sensors and velocity measurement. An electro-optic sensor

consist of three main components: optic sensor, a light source and an electric trigger.

To begin, an optic sensor is a light source and sensor all in an optical fiber.

Within the optic fiber is a LED to shine through the fiber, in which, the fiber has

properties to reflect most of the original light to the other end of the fiber. At the other of

the fiber is a small circuit that consists of a transistor and a resistor (figure 3.4.2.1). The

transistor has a certain current transfer ratio. Depending on the range of voltages the

measure device (microcontroller) this, along current transfer ratio, will determine the

value of the pull-up resistor. The second part of an electro-optic sensor, is the LED that

is used to emit light throughout the entire fiber. The final part of the electro-optic sensor

39

is the electric trigger. The electric trigger is usually a separate device that you used to

measure current through the pull-up resistor. In our case, the microcontroller is the

electric trigger to constantly measure the current at the logic output of the sensor. The

current value depending on the amount of light will determine a logic high (1) or low (0).

Figure 3.4.2.1 Sensor schematic

For our project accuracy is big requirement we want the sensor to be as reliable

as possible. The electro-optic sensor does provide very accurate highs and lows. It is

also relatively low cost and easy to implement into our dispenser cup design. The

reason for not choosing this sensor to provide these really accurate highs and lows you

need to have really specific values for all the parts within the sensor. These sensor are

mostly used to detect very small changes when we are trying to detect a larger changes

in light.

3.4.2 Chemiresistors This is one of the alternative solutions that the design team proposed. The way it

works is that it takes the chemicals that are within the detergents/softener and bleach.

Having these touching the base of the chemiresistor would then produce an electrical

40

current. Different materials create different electrical currents and the user gets to

monitor those currents. With this being said, the team then could determine what

material is currently being sensed through the chemiresistor and then the team could

determine what to do with the data given. For example the team could decide to light up

the LED into the red light to show that it is the wrong material. Another way is that the

LED could be turned into green to show that it is the right material that has been poured

in the cup. This is an alternative sensor that is suggested because it is also quite cheap

in cost. Refer to Figure 3.4.2 for the way that Chemiresistors work graphically.

Figure 3.4.2 The way Chemiresistors work

41

3.4.3 Photoresistor

The light sensing concept consists of emitting light through the contents inside

the dispenser cup. In mind of keeping our design simple and cost effective, we decided

to go with a LED as our light source and a photoresistor as our light detector (figure

3.4.3.1). Using this design the only components needed are: two different resistors, a

photoresistor, a LED and a voltage supply. Only needing five total components can

keep the total cost to a minimum and also gives us the chance to experiment with

different parts and values for this design. With the design of this sensor being very

straight forwards it provides very accurate readings with minimal failure. A very accurate

sensor is detrimental to the customer since the washing machine is used in rough

condition. Violent vibrations, residual moisture, temperature flux and chemical corrosion

are the external factors that can possibly cause our sensor to fail. By using the

suggested design, these factors will have an insignificant effect on our light source and

photoresistor in detecting a change in the intensity of light.

Figure 3.4.3.1 Photoresistor Sensor Diagram

The device sensing the light is the photoresistor. The light from the LED is

essentially what the photoresistor is constantly monitoring and is told to the user by the

42

changing value of its resistance. Well how and why is light effecting the resistor? The

answer to that is photoconductivity; this is the driving principle behind the photoresistor.

Photoconductivity is the electrical phenomenon in which a material becomes more

electrically conductive due to the absorption of electromagnetic radiation (light). The

next question may be what material of the resistor gives it the photoconductive

properties? The material that makes this possible is an inorganic chemical called

cadmium sulfide (CdS). This chemical is intrinsic when undoped, meaning that photons

excite the valence electrons across the band gap to become conductive electrons.

When light strikes the surface of the cadmium sulfide the electrons get a boost in

energy and they hop across the band gap of 2.4 volts and move freely (figure 3.4.3.2).

In the graph you can see the x-axis the electric potential and the y-axis is the energy of

the photons in cadmium sulfide. At 2.4 volts the photon's energy is excited and the

value of it increases rapidly. In addition to the electron roaming free, it also creates a

hole that is technically positively charged and wants to be filled by an electron making

the composition of the material impure and causes the conductivity to rise. In terms of

the resistor, current can flow easily through it, making a very low resistance in light and

a very high resistance in the dark. The cadmium sulfide is made into a thin track the

runs across the electrodes and then connects to the terminals of the resistor (figure

3.4.3.3). This makes the photoresistor a passive element meaning it doesn't have a P-N

junction.

43

Figure 3.4.3.2 CdS (Volts vs. Energy)

Figure 3.4.3.3 Structure of a Photoresistor

One of the key properties is the how the frequency of the light affects its

conductivity. It just so happens that cadmium sulfide is most conductive in visible light

with a peak sensitivity between 560-600 nm, which is lighter shades of blue or green

light.

44

3.5 Power Supply Section

One of the main design requirements was to supply the power wirelessly. First it

was necessary to calculate how much voltage and current were needed to power all the

necessary components. First it was needed to consider that the microcontroller, one of

the main components, needs between 3.3-3.6V to function correctly, for the voltage

divider section of the sensor another 3.3V would be needed, and lastly to power each

green LED 2.2V and around 20 mA of currents would be needed.

At the end it was deemed that one source of 3.3V and around 60mA of current

would be necessary. This power supply would be located in the main system, or the

washing machine, and it is required to transmit this power wirelessly. The most common

method to wirelessly transmit power is through induction. Induction is a fairly easy

method to implement, two coils are needed, and one is the sending coil and is where

the power is applied. When current flows through the coil it will create and

electromagnetic field that will propagate and touch the other coil. The other coil is the

receiving coil, when this coil is hit by the electromagnetic waves it will induct both

current and voltage which will propagate through the circuit. However, with induction

about 50% of the power is loss during propagation, so the coils would have to be very

big for the power to be transmitted even short distances. As the design will be

implemented in the small space of a dispenser cup this method did not seem so

feasible. 3.5.1 Solar Cell and Rechargeable Battery

The selected method to power the dispenser cup was to use a rechargeable

battery and a solar cell that would recharge said battery. While this method cannot be

considered wireless power, it would make the dispenser cup self-powered which is the

ultimate goal. The schematic of the circuit is shown below on figure 3.5.1.1. As

previously mention the battery would have to be a 3.3V battery, which can provide at

least 60mA of current. When the battery was chosen, it was determined that the current

provided was more than 60mA, this problem was easily solved by placing resistors that

limit the current that goes through the LED, and so, preventing the burning of the LEDs.

45

Figure 3.5.1.1 Battery charger

The second main component is the solar panel, the one used is a 6V solar panel. This

means that on optimal conditions it will produce 6V. When the design was tested it was

measured that with minimal ambient light the solar panel produced 3.8-4.6V. This range

is higher than the 3.3V battery, as the solar panel voltage is higher than the battery this

means that the voltage drop will occur in the battery, charging it. However, when there

is no light the solar panel will not produce any voltage, so the battery would try to

discharge through the solar panel. To impede this, a zener diode was placed, the zener

diode will not allow the battery to discharge through the solar panel.

3.6 Data Communication

The data communication is one of the important part. The communication system

is consist by two part of data communication: wire communication and wireless

communication.

3.6.1 wire communication

As we have shown in figure 3.2.3.1, one of the microcontrollers is embedded with

the USB to make it easy to communicate with the computer or ALU. Since the USB port

is very common right now, USB maybe the best choice of wired communication. To

46

communicate with the computer, X-CTU is a necessary tool for serial port to transceive

and receive data. With the help of hardware (USB port and microcontroller) and the

software (X-CTU), we can easily communicate between computer and microcontroller

3.6.2 Wireless communication

Since the computer is not wired with the microcontroller on the dispenser cup

directly, wireless communication between the two microcontroller is necessary. The

whole communication system will be implemented like this: 1. The user enters the cycle

number into the computer. 2. The computer will transfer the cycle number to the

microcontroller through USB port. 3. The microcontroller on USB will transfer the data

to the microcontroller on dispenser cup wirelessly. 4. The microcontroller on the

dispenser cup get the information and control everything directly. so the whole system

will be shown in figure 3.6.2

Figure 3.6.2

47

Chapter 4 - Data Tests

4.1 Sensor Testing

To start off, accuracy and efficiency were the two main principles of the sensor

that we were designing. Testing was used throughout the course to perfect the sensor

of our design. Establishing which light would provide us with a distinct range of voltages

could help ensure that the sensor would be able to determine between liquid and

powdered detergent and fabric softener. This data can then be used with our

microcontroller to aid the microcontroller if the right material is in the right cup.

4.2 Photoresistor Testing

Initial testing was done on the photoresistor would function properly for what we

were planning to implement it for. We used the lab multimeter to measure the resistance

of the photoresistor, this was done by attaching one of the leads to each end. We

determine to test the resistor in ambient light, complete darkness and in an empty cup it

the LED shining on it (base resistance). These results are seen in table 4.2, the resistor

is highest when it is in complete darkness or minimal light exposure and then has the

least resistance value when sitting in ambient light. The base resistance value was

much closer to the ambient light value but was slightly higher indicate that the LED was

not as bright as the ambient light.

Photoresistor values

Light Intensity Covered Base (inside unfilled dispenser cup)

Ambient

Resistance (ohms) 160K 26.7K 16.7K

Table 4.2

48

4.3 LED color testing

Once the configuration and Photoresistor values were determined, team eight

could conduct test to decide which color would be best suited for this project. We used a

RGB LED was used to test multiple colors and keep the testing consistent. Power

supplies were used to ensure that we were testing with the same conditions to provide

us with some concrete values to use for the microcontroller. Using the RGB we testing

the colors red, green and blue. First the different colors were used to test the base

voltage when no contents were in the cups. Once that was done we tested the color

when liquid detergent, powdered detergent and fabric softener was place into the cup.

These results are shown in table 4.4.

RGB Color

R G B

Base (V) 0.49 0.30 0.38

Liquid detergent (V) 0.61 0.38 0.45

Liquid Powder (V) 1.1 1.1 1.1

Fabric softener (V) 0.58 0.34 0.43

Table 4.3

49

Chapter 5 - Dispenser Cup: Final Summary

5.1 Summary

Team eight has created a dispenser cup that is powered on its own and also has

wireless communications with the main system. This cup can also detect materials such

as powder detergent, liquid detergent, softener and bleach. The design team has

achieved the various goals that were proposed by whirlpool and has even furthermore

improved on it.

There are many challenges throughout this project that whirlpool posed. One of

the challenge is the wireless communication. Wireless communication is a really hard

concept because the parts that the team tested with are expensive and would not meet

the budget constraint which is to be under four dollars. The first prototype stage the

team used the MSP430G2553 to light up the six LEDS that is presented on the cup.

The team is able to light them up in different orders enabling the user to know which

contents to pour in the cup. However this did not have any wireless communication to

the system. Therefore the team implemented Atmega128RFA1 which has the wireless

aspect. The team is able to successful program this microcontroller and ensure that one

of the project goals were met.

The second challenge the team encountered is sensing the material that is within

the cup. Whirlpool wishes that the team could build off last semester’s project however

the team did not receive last semester’s prototype and had to rebuild the sensor

system. The team decided to use photoresistor along with LEDs to determine the

material inside the cup. One issue the team had is that the photoresistor is extremely

sensitive to light. This issue is due to the fact that the team did not have a very

controlled environment and different light sources caused different readings. Although it

is not very controlled however after reading the correct values the team is still able to

accomplish what the dispenser cup needs to do. Design team eight is very glad that

they have been given the opportunity to work on this project and know that they are

helping Whirlpool and the customers of Whirlpool to a better washing machine system.

Figure 5.1 shows the final product and the LEDS lighting up.

50

Figure 5.1 Full Dispenser Cup system

5.2 Lessons Learned

● Always have a backup plan (prototyping, parts)

● Have flexible dates and stay on schedule

● Having a controlled environment for testing is important

● Electrical parts are delicate, and applying too much voltage/current could

damage the equipments

● Working as a team is faster than working as an individual

● Prototype testing is important to see where the improvements could be made

● Presentations enhance not only presenting skills but requires one to fully

understand the subject at hand

● Communications with superiors and peer is the key to success

51

5.3 Further Improvements

Although the team has accomplished the given task at hand, the team believes

there are still further improvements that could be made to further enhance the strength

in technology of the dispenser cup. In this section the team will further explore these

improvements that will be suggested for the future.

One of the improvement that the team suggested is to use rechargeable button

cells. The reason is that the team currently uses a rechargeable battery that has quite

some size. As we begin to package our final prototype, the team noticed that it might be

troublesome with this large battery. Therefore the team suggests that rechargeable

button cells could occupy less space and also achieve the same goal. The way that this

is done is stacking the button cells or arranging them in such an order to achieve certain

voltage/current. This way it could potentially occupy less space and gives greater

amount of resources for the dispenser cup. Button cells are also cheaper when it comes

to budget issues. This guarantees a lower cost that will probably yield a larger outcome.

Another improvement that the team suggested is using creating a unique PCB for

the dispenser cups. The reasoning behind this is that there were too many wires and

and also the breadboard that the team currently uses also occupies quite an amount of

space. Therefore having a PCB designed specifically for dispenser cups and having all

the connections ready to go would make the dispenser cup more efficient and easy to

implement.

Another improvement that the team suggests is finding solar cells that are more

light sensitive. The team tried to use one dollar calculator solar cells however soon to

realize they are fake and not useable. The team had already bought a solar cell before

hand however it only provided around 4.5V which is enough for our battery because we

had switched to a 3.3V battery. However the team suggests getting a larger solar cell

could help with the dispenser cup power incase there are other requirements that may

be needed in the future.

The last improvement suggestion is to enhance the detection device. The team

has realized that the photoresistor is very sensitive to light. Due to an relatively

uncontrolled environment it was hard for our programming/testing crew to successfully

figure out the range to detect either detergent, softener or bleach. This is due to that the

52

photoresistor is very sensitive to light and readings could differentiate based on where

the cup is located at the time. Therefore the team strongly suggests a better sensor with

a more controlled environment could enhance the quality of the dispenser cup.

53

Chapter 6 - Appendix 1

Left to Right: Daniel Gomez, Connor Grossman, Gao Xin, Hongyi Shen, Daniel Sun

6.1 Technical and Non Technical Roles

At the beginning of this course, ECE 480, the team was assigned different roles

for each individual. As they course of the semester went on new roles came up relating

to our project and we assigned according to everyone’s skill set. Below are the roles

that were assigned to the team members.

54

6.2 Daniel Sun

Daniel Sun’s Technical role is the senior design team manager. He is also

responsible for the selection of resistor values for our circuit designs for sensors and

power supplies. The placement of the sensors within the cup and photoresistor is also

decided by Daniel. Daniel decided to test with LEDs and Photoresistors to get the

readings for the microcontroller enable to program the microcontroller. Programming the

microcontroller requires values from photoresistor to determine whether the material

that is poured in the cup is indeed what is needed to be poured in the cup. Daniel Also

organized all the meetings for the group and kept the group on schedule.

Besides being the team manager, Daniel also bought most of the materials that

were needed to built the prototype and create the final product. He has set up great

meetings with the team and planning ahead and always keeping the team on schedule.

6.3 Connor Grossman

Connor’s first given role at the beginning of the project was document

preparation. His responsibility with this was edit and revises all documents that were

prepared over the course. He was the last person to look at the document before

submitting them to make sure grammar was correct and to make sure every section

was as detailed as possible. Another task that came along with this was working on and

checking over assignments that were turned in during the semester.

As the project progressed Connor took the role of designing and testing of the

sensor. This included testing different colors of light to ensure the most accurate

reading from the microcontroller. Initially Connor decided that a base voltage (without

material in cup) would be around 2 volts so that when material was poured in the

voltage would rise around 3 voltage, this would be a sufficient difference for the project.

Later it was discover that the microcontroller could only read up to 1.6 voltage. The

base voltage needed to be adjusted so this constraint would be accounted for, the base

voltage was then moved around 0.30 volts to make sure that any reading wouldn’t

exceed 1.6 volts. Connor planned and conducted all testing for the sensor and used this

data to make decisions about the sensor.

55

Along with these task, Mr. Grossman also took a lead role with phone conference

calls with Jason and Jeff that included speaking and explaining progress of team eight.

Connor was the main source of communication with Whirlpool and was in charge of

relaying information to them.

6.4 Daniel Gomez

Mr. Gomez technical role is the microcontroller programmer and presentation

manager. Mr. Gomez has investigated the optimal configuration of the microcontroller

for interfacing with the dispenser cup and how to implement the wireless communication

with the main system of the washing machine. The effects of sample-and-hold time and

reference voltage configurations of the Analog-to-Digital converter have been

extensively tested by him. Mr. Shen and Mr. Gomez have collaborated to establish the

best protocol for the wireless communications and the sensor interfacing. The

microcontroller programming for serial communication configuration and protocol were

researched and implemented by him.

The second role of Mr. Gomez is Lab Coordinator, Mr Gomez was in charge of

ordering all the parts necessary for the prototype. Mr Gomez was in charge of setting

meetings with the facilitator and he also help with the design of the sensor and power

supply.

6.5 Hong Yi Shen

Mr. Shen’s technical role is the microcontroller programmer. Based on Mr.

Shen’s previous working experience on programming the microcontroller for many

robot. Mr. Shen is familiar with the Atmega128rfa1 microcontroller. He configured

wireless communication, UART, Analog to Digital converter, LED control for

Atmega128rfa1. He work with other teammates closely, to make sure the the program

can be used by the configured code. In addition, Mr. Shen also in charge to weld the

brand new microcontroller with the chips. Due to the limitation of the microcontroller

port, for example, there are only 8 pin for Analog to Digital and some other pins have

limitation functions like transceive and receive so he arranged the pin for LEDs was also

done by Mr.Shen.

56

As the presentation preparer, Mr. Shen and Daniel Sun invited other members to

make powerpoints online and after everyone finish their own part, he make up the team

to do the practice and make sure the time is not too long or too short. If necessary, he

will discuss with the team to adjust some parts.

6.6 Gao Xin

Ms. Xin’s technical role in the team is the designer of the 3D Print Dispenser Cup

Model and the website manager. She used the Siemens NX 9.0 to design the dispenser

cup. The initial design of the disperser cup has three layers that can assemble together

as the whole Dispenser Cup system, which has different functions and features for each

layer. The first layer has three cups for detergent, softener and bleach with LEDs

besides each cup. The LED turns to red when customer put the wrong material into the

cup. For example, when pour the bleach into the detergent cup, the LED will turn to

Red. LED turns to green meaning the material is poured into the correct cup. The

second layer has some storage place for the circuit. And the third layer contains the

common path for all three cups and the storage place. However, based on the project

budget, the initial design does meet the satisfaction, which means a modified design will

be needed.

The modified design is much simpler than the initial design, since the storage

place for the microcontroller and other parts of the circuits do not need to be count into

consideration at this point. The modified cup has only one layers, that contains three

cups for detergent, softener and bleach, which also has three LEDs beside each cup.

As the web manager, Ms. Xin also created a team website that has all the

information about the project. Ms. Xin updated the website every week with images,

videos and report documents.

57


7.1 References

http://www.johnloomis.org/ece445/topics/egginc/pt_app.html

http://www.radio-

electronics.com/info/data/semicond/phototransistor/photo_transistor.php

http://en.wikipedia.org/wiki/Photodiode

http://www.teccogroup.com/LED-Rope-light-p404.html

http://en.wikipedia.org/wiki/LED_lamp

http://naturescreationsinc.com/alternative-systems/led-lighting/

http://en.wikipedia.org/wiki/Analog-to-digital_converter

http://www.radio-electronics.com/info/data/resistor/ldr/light_dependent_resistor.php

http://en.wikipedia.org/wiki/Universal_asynchronous_receiver/transmitter

http://kids.britannica.com/comptons/art-53789/Photoresistor

http://www.edn.com/design/analog/4368794/Simple-night-light-uses-a-photoresistor-to-

detect-dusk

http://www.education.rec.ri.cmu.edu/content/electronics/boe/light_sensor/1.html

http://nguyenmarysci4.tumblr.com/post/45739083253/what-the-led-how-it-does-it-work

“Electro-optical Senor” Wikipedia. Wikimedia Foundation Inc., 4 Feb. 2015. Web. 13

Mar. 2015.

“What is an Optical Sensor?” wiseGEEK. Conjecture Corperation, 12 Mar. 2015. Web.

13 Mar. 2015.

Ball, Stuart. “Exploring optical and magnetic sensors.” Embedded. 17 Jun. 2003. Web.

13 Mar. 2015.

“Cadmium Sulfide” Wikipedia. Wikimedia Foundation Inc., 22 Feb. 2015. Web. 24 Mar.

2015.

http://www.johnloomis.org/ece445/topics/egginc/pt_app.html

http://www.radio-electronics.com/info/data/semicond/phototransistor/photo_transistor.php

http://www.radio-electronics.com/info/data/semicond/phototransistor/photo_transistor.php

http://en.wikipedia.org/wiki/Photodiode

http://www.teccogroup.com/LED-Rope-light-p404.html

http://en.wikipedia.org/wiki/LED_lamp

http://naturescreationsinc.com/alternative-systems/led-lighting/

http://en.wikipedia.org/wiki/Analog-to-digital_converter

http://www.radio-electronics.com/info/data/resistor/ldr/light_dependent_resistor.php

http://en.wikipedia.org/wiki/Universal_asynchronous_receiver/transmitter

http://kids.britannica.com/comptons/art-53789/Photoresistor

http://www.edn.com/design/analog/4368794/Simple-night-light-uses-a-photoresistor-to-detect-dusk

http://www.edn.com/design/analog/4368794/Simple-night-light-uses-a-photoresistor-to-detect-dusk

http://www.education.rec.ri.cmu.edu/content/electronics/boe/light_sensor/1.html

http://nguyenmarysci4.tumblr.com/post/45739083253/what-the-led-how-it-does-it-work

58


8.1 Parts Identification

Figure 8.1-1 Rechargeable button Cell

Figure 8.1-2 9v Rechargeable Battery

59

Figure 8.1-3 First Prototype Cup

60

Figure 8.1-4 RGB LED

Figure 8.1-5 Photoresistor

61

Figure 8.1-6 Solar Cell

62

Figure 8.1-7 Materials From left to right (Bleach, Detergent, Softener, Detergent,

Bleach)

63

8.2 Programming Screen

atmel studio 6.2 (programming software)

64

X-CTU 5.2.8.6 ( serial port tool)

65

8.3 Testing the Code

1. head file radio.h (from sparkfun.com)

/*

* radio.h

*

* Created on: Jan 15, 2012

* Author: ratmandu

*/

#ifndef RADIO_H_

#define RADIO_H_

#define TRX_MAX_FRAME_SIZE 127

#define TRX_FIFO_SIZE 128

#define TRX_WAIT_BEFORE

//#define TRX_WAIT_AFTER

#define SHORT_ADDR_L 0xFE

#define SHORT_ADDR_H 0xED

#define RADIO_CHANNEL 20

#define PAN_ADDR 0xACDC

#define MAC_ADDR_0 0x01





#define MAC_ADDR_5 0xab

#define MAC_ADDR_6 0xcd

#define MAC_ADDR_7 0xef

66

#define modifyReg(var, mask, value) (var = ((var & ~mask) | (value & mask)))

// Transceiver state status

#define TRX_STATUS_MASK

0x1f

enum

{

STATUS_BUSY_RX = 0x01,

STATUS_BUSY_TX = 0x02,

STATUS_RX_ON = 0x06,

STATUS_TRX_OFF = 0x08,

STATUS_PLL_ON = 0x09,

STATUS_SLEEP = 0x0f,

STATUS_BUSY_RX_AACK = 0x11,

STATUS_BUSY_TX_ARET = 0x12,

STATUS_RX_AACK_ON = 0x16,

STATUS_TX_ARET_ON = 0x19,

STATUS_STATE_TRANSITION_IN_PROGRESS = 0x1f

};

// Transceiver state change commands

enum

{

STATE_NOP = 0x00,

STATE_TX_START = 0x02,

STATE_FORCE_TRX_OFF = 0x03,

STATE_FORCE_PLL_ON = 0x04,

STATE_RX_ON = 0x06,

STATE_TRX_OFF = 0x08,

STATE_PLL_ON = 0x09,

67

STATE_RX_AACK_ON = 0x16,

STATE_TX_ARET_ON = 0x19

};

#define PHY_RSSI_MASK 0x1f

#define PHY_RSSI_RANDOM_MASK 0x60

#define TRX_BUF(i) _SFR_MEM8(0x180 + i)

#define ReadBit(var, bit) (((var) & (1 << (bit))) != 0)

static volatile uint8_t rssi;

static uint8_t* frameData[125];

static uint8_t frameLength;

enum

{

VERSION_A = 2, // A and B are both 2 according to the data sheet

VERSION_B = 2,

VERSION_C = 3,

VERSION_D = 4

};

uint8_t currentlyTransmitting;

void trx_radioInit();

void trx_setChannel(uint8_t channel);

void trx_send(void* data, uint8_t len);

void trx_calibrate();

void trx_setTXPower(uint8_t power);

void trx_setRXSensitivity(uint8_t level);

void trx_setTRXState(uint8_t state);

void trx_enterTRXSleep();

68

void trx_leaveTRXSleep();

void trx_setPANID(uint16_t panid);

void trx_setShortAddress(uint16_t shortaddr);

void trx_setExtAddress(uint8_t* extaddr);

void trx_waitWhile(uint8_t status);

void trx_getExtAddress(uint8_t* addr);

uint16_t trx_getShortAddress();

uint16_t trx_getPANID();

uint8_t trx_isSleeping();

uint8_t trx_getTRXState();

uint8_t trx_getRandomNumber();

uint8_t trx_getRSSI();

#endif /* RADIO_H_ */

2. head file serial.h (from sparkfun.com)

/*

* serial.h

*

* Created on: Jan 29, 2012

* Author: ratmandu

*/

#ifndef SERIAL_H_

#define SERIAL_H_

#define SERIAL_0_RX_BUF_LEN 256


69

char serial0RxBuf[SERIAL_0_RX_BUF_LEN];


uint8_t bytesInSerial0RxBuf;


uint8_t buffer0ReadLoc, buffer0WriteLoc;


void initSerial0(uint32_t baud);


void serial0PutChar(unsigned char data);


void serial0PutString(unsigned char *str);


void initSerial0RxBuf(void);


void writeToBuffer0(unsigned char data);


unsigned char readFromBuffer0(uint8_t *bufsize);


void buf0SkipTo(unsigned char data);


uint8_t buf0Size(void);


void USART0_RX_vect(void);


#endif /* SERIAL_H_ */

3. head file trx.h (written by Xinyu Zhao)

70

/*

this head file include most of basic function of wireless function

*/

#ifndef TRX_H_INCLUDED

#define TRX_H_INCLUDED



//////////////////////////////////////////////////////////////////////////////////

//seiral.h




















71






/////////////////////////////////////////////////////////////////////////////////////

//radio.h

#define TRX_MAX_FRAME_SIZE 127

#define TRX_FIFO_SIZE 128

#define TRX_WAIT_BEFORE

//#define TRX_WAIT_AFTER

#define SHORT_ADDR_L 0xFE

#define SHORT_ADDR_H 0xED

#define RADIO_CHANNEL 20

#define PAN_ADDR 0xACDC






#define MAC_ADDR_5 0xab

#define MAC_ADDR_6 0xcd

#define MAC_ADDR_7 0xef

#define modifyReg(var, mask, value) (var = ((var & ~mask) | (value & mask)))

// Transceiver state status

72

#define TRX_STATUS_MASK

0x1f

enum

{

STATUS_BUSY_RX = 0x01,

STATUS_BUSY_TX = 0x02,

STATUS_RX_ON = 0x06,

STATUS_TRX_OFF = 0x08,

STATUS_PLL_ON = 0x09,

STATUS_SLEEP = 0x0f,

STATUS_BUSY_RX_AACK = 0x11,

STATUS_BUSY_TX_ARET = 0x12,

STATUS_RX_AACK_ON = 0x16,

STATUS_TX_ARET_ON = 0x19,

STATUS_STATE_TRANSITION_IN_PROGRESS = 0x1f

};

// Transceiver state change commands

enum

{

STATE_NOP = 0x00,

STATE_TX_START = 0x02,

STATE_FORCE_TRX_OFF = 0x03,

STATE_FORCE_PLL_ON = 0x04,

STATE_RX_ON = 0x06,

STATE_TRX_OFF = 0x08,

STATE_PLL_ON = 0x09,

STATE_RX_AACK_ON = 0x16,

STATE_TX_ARET_ON = 0x19

};

73

#define PHY_RSSI_MASK 0x1f

#define PHY_RSSI_RANDOM_MASK 0x60

#define TRX_BUF(i) _SFR_MEM8(0x180 + i)

#define ReadBit(var, bit) (((var) & (1 << (bit))) != 0)

static volatile uint8_t rssi;

static uint8_t* frameData[125];

static uint8_t frameLength;

enum

{

VERSION_A = 2, // A and B are both 2 according to the data sheet

VERSION_B = 2,

VERSION_C = 3,

VERSION_D = 4

};

uint8_t currentlyTransmitting;


void trx_setChannel(uint8_t channel);

void trx_send(void* data, uint8_t len);

void trx_calibrate();

void trx_setTXPower(uint8_t power);

void trx_setRXSensitivity(uint8_t level);

void trx_setTRXState(uint8_t state);

void trx_enterTRXSleep();

void trx_leaveTRXSleep();

void trx_setPANID(uint16_t panid);

void trx_setShortAddress(uint16_t shortaddr);

void trx_setExtAddress(uint8_t* extaddr);

74

void trx_waitWhile(uint8_t status);

void trx_getExtAddress(uint8_t* addr);

uint16_t trx_getShortAddress();

uint16_t trx_getPANID();

uint8_t trx_isSleeping();

uint8_t trx_getTRXState();

uint8_t trx_getRandomNumber();

uint8_t trx_getRSSI();

//////////////////////////////////////////////////////////////////////////////

//Define the frame buffer of the Atmega128rfa1(use for RF transmission)

#define MMIO_REG(mem_addr, type) (*(volatile type *)(mem_addr))

#define TRX_FRAME_BUFFER(index) MMIO_REG(0x180 + (index), uint8_t) //Note:

Frame buffer of Atmega128rfa1 has 255 bytes

#define sbi(var, mask) ((var) |= (uint8_t)(1 << mask)) //set a bit (bit = 1)

#define cbi(var, mask) ((var) &= (uint8_t)~(1 << mask)) //clear a bit (bit = 0)

void trx_setChannel(uint8_t channel) //function to select radio channel

{

PHY_CC_CCA = ((PHY_CC_CCA & ~0x1F) | (channel & 0x1F));

}

void trx_calibrate() //calibrate transceiver

{

FTN_CTRL |= (1 << FTN_START);

PLL_CF |= (1 << PLL_CF_START);

PLL_DCU |= (1 << PLL_DCU_START);

}

void trx_setTXPower(uint8_t power) // transmit power control

{

75

PHY_TX_PWR = ((PHY_TX_PWR & ~0x0F) | (power & 0x0F));

}

void trx_setRXSensitivity(uint8_t level) //Receiver sensitivity control

{

RX_SYN = ((RX_SYN & ~0x0F) | (level & 0x0F));

}

void trx_setTRXState(uint8_t state) //set transceiver state

{

while ((TRX_STATUS & 0x1F) == 0x1F) //check if state change complete

;

TRX_STATE = state;

}

void trx_enterTRXSleep() //enter TRX-OFF state

{

trx_setTRXState(STATE_TRX_OFF);

}

void trx_leaveTRXSleep() //enter RX_ON state

{

trx_setTRXState(STATE_RX_ON);

}

void trx_setPANID(uint16_t panid) //set PANID for both low and high addresses

{

PAN_ID_0 = (panid & 0xFF);

PAN_ID_1 = ((panid >> 8) &0xFF);

}

void trx_setShortAddress(uint16_t shortaddr) //set the low and high short addresses

76

{

SHORT_ADDR_0 = (shortaddr & 0xFF);

SHORT_ADDR_1 = (shortaddr >>8) &0xFF;

}

void trx_setExtAddr(uint8_t* extaddr) //set IEEE address

{

IEEE_ADDR_0 = extaddr[0];








}

void trx_waitWhile(uint8_t status) //wait till state change complete

{

while (trx_getTRXState() == status)

{

;

}

}

uint16_t trx_getShortAddress() //read the short addresses

{

uint16_t shortAddr;

shortAddr = (SHORT_ADDR_H << 8);

shortAddr |= SHORT_ADDR_L;

return shortAddr;

77

}

uint16_t trx_getPANID() //read the PANID

{

uint16_t panID;

panID = (PAN_ID_1 << 8);

panID |= PAN_ID_0;

return panID;

}

void trx_getExtAddr(uint8_t* addr) //read IEEE addresses

{

addr[0] = IEEE_ADDR_0;








}

uint8_t trx_isSleeping() //check if transceiver is on sleeping state

{

if (trx_getTRXState() == STATUS_SLEEP)

return 1;

else

return 0;

}

uint8_t trx_getTRXState() //return transceiver state

78

{

return (TRX_STATUS & TRX_STATUS_MASK);

}

uint8_t trx_getRSSI() // read PSSI

{

return PHY_RSSI & PHY_RSSI_MASK;

}

/*=================================================================

=================================*/

//function for data array transmit:

//write into frame buffer and transmit data from frame buffer

void trx_send_data(uint8_t command)

{

// make sure we aren't receiving anything, wait till RX_BUSY finished

trx_waitWhile(STATUS_BUSY_RX);

// turn on PLL and prepare for transmission ( change to PLL_O11N state)

trx_setTRXState(STATE_PLL_ON);

//write data into frame buffer

//Note: To send more than one byte data, write them into the rest byte of the

frame buffer (total 255)

TRX_FRAME_BUFFER(1)=command;

//TRX_BUF(i+1) = 't'; //last bit is written 't'!

while (trx_getTRXState() != STATUS_PLL_ON) //wait till PLL_ON state change

complete

79

;

// start transmission

trx_setTRXState(STATE_TX_START);

}

#endif

4. code for the microcontroller on the usb port. C.file (edit by Hongyi Shen)

/*

* com.c

*

* Created: 4/20/2015 5:39:37 PM

* Author: shenhon2

*/

#define F_CPU 16000000UL

#include <avr/io.h>

#include <stdio.h>

#include <avr/interrupt.h>

#include <util/delay.h>

#include <avr/power.h>

#include <util/atomic.h>

#include <string.h>

#include "trx.h" //h. file define basic function and constant about wireless

communication

//RF communication's function defined

80

//=====================================

//uint8_t currentlyTransmitting;


//=======================================================

//printf function define

static int uart_putchar(char c, FILE *stream);

uint8_t uart_getchar(void);

static FILE mystdout = FDEV_SETUP_STREAM(uart_putchar, NULL,

_FDEV_SETUP_WRITE);

uint8_t command_recieved=0;

int main(void)

{

OSCCAL=0b10001100; // set

calibration byte

//setup I/O port

//1 = output, 0 = input

DDRD = 0b11111011; //PORTD (RX on PD2)

clock_prescale_set(clock_div_1_rc); //set up the clock with division factor of 1

initSerial1(921600); //initiate usart with baud rate of 921600

// initSerial1RxBuf(); //initiate the buffer

trx_radioInit(); //initiate the radio transceiver

printf("commander setup completes, ready for input robotic control

command!\n");

sei(); //set global interrupt

flag here

printf("Cycle 1: Detergent & Bleach\n");

printf("Cycle 2: Detergent & Softener\n");

81

printf("Cycle 3: Detergent \n");

printf("Cycle 4: Detergent & Bleach & Softener\n");

printf("Please enter the cycle number: ");

while(1) //wait until next

interrupt coming

{

}

}

//RF function description

//=================================================================

===============//

void trx_radioInit() //initiate transceiver

{

cbi(SCCR0, SCCKSEL); //clear SCCKSEL bit to 0 because when

trx coming into sleep mode it will automatically set as 1. but we need it as 0 when it

wake up

uint8_t addr[8];

addr[0] = MAC_ADDR_0; //distribute mac address

addr[1] = MAC_ADDR_1;







IRQ_STATUS |= (1 << TX_END) | (1 << RX_END) | (1 << RX_START);

//pending interrupt request

82

IRQ_MASK |= (1 << TX_END_EN) | (1 << RX_END_EN) | (1 <<

RX_START_EN); //enable interrupt

trx_setTRXState(STATE_FORCE_TRX_OFF); //enter TRX_OFF state

while (trx_getTRXState() != STATUS_TRX_OFF); //wait till state change

complete

trx_setExtAddr(addr);

trx_setChannel(RADIO_CHANNEL); //select channel 20

trx_setPANID(PAN_ADDR); //giving panid address

trx_setTRXState(STATE_RX_ON); //enter RX_ON state

while (trx_getTRXState() != STATUS_RX_ON); //wait till state change

complete

trx_calibrate();

_delay_ms(500);

printf("RF transciever setup!!!\n");

}

//**************************************************************************************************

**//

//function for usart

//initial seiall which work for buad rate as 921600

void initSerial1(uint32_t baud)

{

uint32_t baudreg;

baudreg = (F_CPU/baud/8-1);

UBRR1H = (uint8_t)((baudreg >> 8) & 0xFF);

UBRR1L = (uint8_t)(baudreg & 0xFF);

//UCSR1A = 0x00;

83

sbi(UCSR1A,U2X1);

UCSR1B = (1<<TXEN1) | (1<<RXEN1)|(1<<RXCIE1); //activate RX interrupt

UCSR1C = 0x06; //asynchronous, no parity,

stdout = &mystdout; //Required for printf init

printf("Serial communication setup!!!\n");

}

static int uart_putchar(char c, FILE *stream)

{

if (c == '\n') uart_putchar('\r', stream);

loop_until_bit_is_set(UCSR1A, UDRE1);

UDR1 = c;

return 0;

}

uint8_t uart_getchar(void)

{

while( !(UCSR1A & (1<<RXC1)) );

return(UDR1);

}

//interrupt rountine

ISR(TRX24_TX_END_vect) //RX_ON interrupt

{


}

84

ISR(TRX24_RX_END_vect) //Read frame buffer data interrupt

{

if (ReadBit(PHY_RSSI, RX_CRC_VALID) == 0)

{

return;

}

command_recieved = TRX_FRAME_BUFFER(0);

//printf("data is %c\n",command_recieved);

}

ISR(TRX24_RX_START_vect)

{

rssi = PHY_RSSI;

}

ISR(USART1_RX_vect) //Interrupt for serial communication

{

uint8_t keypress;

keypress=UDR1;

printf("\n");

printf("The cycle number is : %c\n", keypress);

trx_send_data(keypress);

printf("data has been sent out\n");

printf("Cycle 1: Detergent & Bleach\n");

printf("Cycle 2: Detergent & Softener\n");

printf("Cycle 3: Detergent \n");

printf("Cycle 4: Detergent & Bleach & Softener\n");

printf("Please enter the cycle number: ");

}

85

5. code for the microcontroller embedded with dispenser cup. C.file (edit by Hongyi

Shen)

/*

* cup.c

*

* Created: 4/20/2015 5:35:16 PM

* Author: shenhon2

*/

//Useful constant define

//================================

#define F_CPU 16000000UL //CPU frequency

#include <avr/io.h>

#include <stdio.h>

#include <avr/interrupt.h>

#include <util/delay.h>

#include <avr/power.h>

#include <util/atomic.h>

#include <string.h>

#include "trx.h" //h. file define basic function and constant about wireless

communication

//RF communication's function defined

//=====================================

//uint8_t currentlyTransmitting;

void trx_radioInit(); //initialize the RF transceiver

//=======================================================

//serial communication function

86

void initSerial1(uint32_t baud); //initialize the serial communication


//printf function define

static int uart_putchar(char c, FILE *stream);

uint8_t uart_getchar(void);

static FILE mystdout = FDEV_SETUP_STREAM(uart_putchar, NULL,

_FDEV_SETUP_WRITE);

//function of adc reader

uint16_t readd();

uint16_t reads();

uint16_t readb();

//function of clear lights

void nolight();

uint8_t TEMP1;

uint8_t TEMP2;

uint16_t TEMP;

uint16_t output;

int main(void)

{

OSCCAL=0b10001100; // set calibration byte

///sbi(PORTB,PORTB1);

clock_prescale_set(clock_div_1_rc); //set up the clock with division factor of 1

initSerial1(921600); //initiate the usart with 921600 baud rate

(serial communication)

DDRB |= 0b11111111;

DDRE |= 0b11111111;

DDRF |= 0b11110000;

DDRG |= 0b11100100;

initSerial1RxBuf(); //initiate the rx buffer

87

trx_radioInit(); //initiate the RF transceiver

sei();//turn on the global interrupt

//set adc

cbi(PRR0,PRADC);

cbi(DDRC,DDC0);

ADMUX=0b11000000; //bit7:6 select voltage reference 1.6V, MUX5 in

ADCSRB and bit 4:0 selects Analog Channel (single ended input ADC0)

ADCSRA=0b10000001; //bit7 ADC enable; Bits 2:0 ADC Prescaler

Select Bits;

ADCSRC=0b00000111; //Bits 7:6 ADC Track-and-Hold Time (ADTHT);

Bits 4:0 ¨C ADSUT4:0: ADC Start-up Time (ADSUT): startup time = 4(ADSUT+1),

minimum 20 ¦Ìs

cbi(ADCSRB,MUX5); //mux5 need to be 0, mux 5 is part of mux0:5

while(1)

{/*

ADCSRA = (1<<ADEN) + (1<<ADSC) + (2<<ADPS0); //enable adc

do

{} while( (ADCSRA & (1<<ADSC))); //wait adc complete

ADCSRA = 0x00;

TEMP1=ADCL;

TEMP2=ADCH;

TEMP = (ADCH << 8) + ADCL;

printf("\n %d ",TEMP1);

printf("\n %d ",TEMP2);

printf("\n %d ",TEMP);

*/

}

88

return 1; //If it gets here, error happens!

}

//function of read data

uint16_t readd()

{

//initialize F0 as adc single read port

cbi(PRR0,PRADC);

cbi(DDRC,DDC0);




Select Bits;



minimum 20 ¦Ìs


//start read


do


ADCSRA = 0x00;

TEMP1=ADCL;

TEMP2=ADCH;


trx_send_data(TEMP);


cbi(ADCSRA,ADEN);

89

sbi(PRR0,PRADC);

_delay_ms(20);

return TEMP;

}

uint16_t reads()

{


cbi(PRR0,PRADC);

cbi(DDRC,DDC0);




Select Bits;



minimum 20 ¦Ìs


//start read


do


ADCSRA = 0x00;

TEMP1=ADCL;

TEMP2=ADCH;




90

cbi(ADCSRA,ADEN);

sbi(PRR0,PRADC);

_delay_ms(20);

return TEMP;

}

uint16_t readb()

{


cbi(PRR0,PRADC);

cbi(DDRC,DDC0);




Select Bits;



minimum 20 ¦Ìs


//start read


do


ADCSRA = 0x00;

TEMP1=ADCL;

TEMP2=ADCH;



91


cbi(ADCSRA,ADEN);

sbi(PRR0,PRADC);

_delay_ms(20);

return TEMP;

}

//RF function Definition

//=================================

void trx_radioInit() //initiate transceiver

{

cbi(SCCR0, SCCKSEL);

XOSC_CTRL|=(0x02);

uint8_t addr[8];

addr[0] = MAC_ADDR_0; //distribute mac address








IRQ_STATUS |= (1 << TX_END) | (1 << RX_END) | (1 << RX_START);

//pending interrupt request

IRQ_MASK |= (1 << TX_END_EN) | (1 << RX_END_EN) | (1 <<

RX_START_EN); //enable interrupt

trx_setTRXState(STATE_FORCE_TRX_OFF); //enter TRX_OFF state

92

while (trx_getTRXState() != STATUS_TRX_OFF); //wait till state change

complete

trx_setExtAddr(addr);

trx_setChannel(RADIO_CHANNEL); //select channel 20

trx_setPANID(PAN_ADDR); //giving panid address

trx_setTRXState(STATE_RX_ON); //enter RX_ON state

while (trx_getTRXState() != STATUS_RX_ON); //wait till state change

complete

trx_calibrate();

printf("RF transceiver initialization succeeds!\n");

}

void nolight()

{

PORTE &= 0b00000011;

PORTB &= 0b00011111;

PORTF &= 0b00011111;

}

//***********************************//

//function definition for serial communication

//initial seiall which work for buad rate as 921600

void initSerial1(uint32_t baud)

{

uint32_t baudreg;

baudreg = (F_CPU/baud/8-1);

UBRR1H = (uint8_t)((baudreg >> 8) & 0xFF);

UBRR1L = (uint8_t)(baudreg & 0xFF);

//UCSR1A = 0x00;

sbi(UCSR1A,U2X1);

93

UCSR1B = (1<<TXEN1) | (1<<RXEN1)|(1<<RXCIE1); //activate RX interrupt

UCSR1C = 0x06; //asynchronous, no parity,

stdout = &mystdout; //Required for printf init

printf("Serial communication setup!!!\n");

}

void initSerial1RxBuf() {

memset(&serial1RxBuf, 0, SERIAL_1_RX_BUF_LEN);

bytesInSerial1RxBuf = 0;

buffer1ReadLoc = 0;

buffer1WriteLoc = 0;

}

//====================================================

static int uart_putchar(char c, FILE *stream)

{

if (c == '\n') uart_putchar('\r', stream);

loop_until_bit_is_set(UCSR1A, UDRE1);

UDR1 = c;

return 0;

}

uint8_t uart_getchar(void)

{

while( !(UCSR1A & (1<<RXC1)) );

return(UDR1);

}

//==========================================================

ISR(TRX24_TX_END_vect) //RX_ON interrupt

94

{


}

ISR(TRX24_RX_END_vect) //Read frame buffer data interrupt

{

if (ReadBit(PHY_RSSI, RX_CRC_VALID) == 0)

{

return;

}

uint8_t command_recieved;

command_recieved=TRX_FRAME_BUFFER(0);//read the data in frame buffer,

received by RF transmission

//following part is just an example: control the light.

//they can be edited on different port and pin or add different code to realize

different function

/* Determine the control command */

switch (command_recieved)

{

case 0x31: //Turn on the LED connected to PB1

//'1' on the keyboard: turn on the LED on PB1

nolight();

//Detergent

sbi(PORTE,PORTE7);

sbi(PORTF,PORTF5);

_delay_ms(10000);

95

cbi(PORTE,PORTE7);

output=readd();

if ((output<=195)&(output >=160))

{

sbi(PORTE,PORTE6);

}

else if((output<155)&(output>160))

{

output=readd();

if ((output<195)&(output >=160))

{

sbi(PORTE,PORTE6);

}

else

{

sbi(PORTE,PORTE5);

}

}

else

{

sbi(PORTE,PORTE5);

}

_delay_ms(2000);

nolight();

_delay_ms(2000);

//Bleach

sbi(PORTB,PORTB7);

sbi(PORTF,PORTF7);

_delay_ms(10000);

96

cbi(PORTB,PORTB7);

output=readb();


{

sbi(PORTB,PORTB6);

}


{

output=readb();


{

sbi(PORTB,PORTB6);

}

else

{

sbi(PORTB,PORTB5);

}

}

else

{

sbi(PORTB,PORTB5);

}

_delay_ms(2000);

nolight();

_delay_ms(2000);

break;

case 0x32: //Turn off the LED connected to PB1

97

//'2' on the keyboard: turn off the LED on PB2

nolight();

//Detergent

//Detergent

sbi(PORTE,PORTE7);

sbi(PORTF,PORTF5);

_delay_ms(10000);

cbi(PORTE,PORTE7);

output=readd();


{

sbi(PORTE,PORTE6);

}


{

output=readd();


{

sbi(PORTE,PORTE6);

}

else

{

sbi(PORTE,PORTE5);

}

}

else

{

sbi(PORTE,PORTE5);

}

_delay_ms(2000);

98

nolight();

_delay_ms(2000);

// softener

sbi(PORTE,PORTE4);

sbi(PORTF,PORTF6);

_delay_ms(10000);

cbi(PORTE,PORTE4);

output=reads();


{

sbi(PORTE,PORTE3);

}


{

output=reads();


{

sbi(PORTE,PORTE3);

}

else

{

sbi(PORTE,PORTE2);

}

}

else

{

sbi(PORTE,PORTE2);

}

_delay_ms(2000);

99

nolight();

_delay_ms(2000);

break;

case 0x33: //Turn off the LED connected to PB1

//'3' on the keyboard: turn off the LED on PB2

nolight();

//Detergent

sbi(PORTE,PORTE7);

sbi(PORTF,PORTF5);

_delay_ms(10000);

cbi(PORTE,PORTE7);

output=readd();


{

sbi(PORTE,PORTE6);

}


{

output=readd();


{

sbi(PORTE,PORTE6);

}

else

{

sbi(PORTE,PORTE5);

}

}

100

else

{

sbi(PORTE,PORTE5);

}

_delay_ms(2000);

nolight();

_delay_ms(2000);

break;



nolight();

//Detergent

sbi(PORTE,PORTE7);

sbi(PORTF,PORTF5);

_delay_ms(10000);

cbi(PORTE,PORTE7);

output=readd();


{

sbi(PORTE,PORTE6);

}


{

output=readd();


{

sbi(PORTE,PORTE6);

}

else

101

{

sbi(PORTE,PORTE5);

}

}

else

{

sbi(PORTE,PORTE5);

}

_delay_ms(2000);

nolight();

_delay_ms(2000);

// softener

sbi(PORTE,PORTE4);

sbi(PORTF,PORTF6);

_delay_ms(10000);

cbi(PORTE,PORTE4);

output=reads();


{

sbi(PORTE,PORTE3);

}


{

output=reads();


{

sbi(PORTE,PORTE3);

}

else

{

102

sbi(PORTE,PORTE2);

}

}

else

{

sbi(PORTE,PORTE2);

}

_delay_ms(2000);

nolight();

_delay_ms(2000);

//Bleach

sbi(PORTB,PORTB7);

sbi(PORTF,PORTF7);

_delay_ms(10000);

cbi(PORTB,PORTB7);

output=readb();


{

sbi(PORTB,PORTB6);

}


{

output=readb();


{

sbi(PORTB,PORTB6);

}

else

{

sbi(PORTB,PORTB5);

103

}

}

else

{

sbi(PORTB,PORTB5);

}

_delay_ms(2000);

nolight();

_delay_ms(2000);

break;



nolight();

sbi(PORTF,PORTF5);

_delay_ms(10);

readd();

break;



nolight();

sbi(PORTF,PORTF6);

_delay_ms(10);

reads();

break;



nolight();

sbi(PORTF,PORTF7);

_delay_ms(10);

104

readb();

break;

default:

break;

}

printf("get the char is %c\n",command_recieved);//

//trx_send_data(command_recieved);

}

ISR(TRX24_RX_START_vect)

{

rssi = PHY_RSSI;

}

105

8.4 Circuit Calculations

Selecting a pull-up resistor would help control what the base voltage of the

sensor. The first thing was to measure the resistance of the photoresistor when there

was an empty cup, this came out to be around 26 kohm. The next to things were pick a

source voltage and a base output voltage. Picking a source voltage of 3.3V was very

simple due to the fact that the microcontroller has a 3.3V output pin. Next was to select

a base output voltage for the sensor. We know that the microcontroller could only

measure between 0 and 1.6V and that the voltage would rise once the material was

poured into the cup. We decided that 0.3V would be a good base voltage that wouldn’t

exceed 1.6 V once materials were added. To solve for this resistor value the voltage

divider equation was used:

𝑉𝑉𝑉𝑉 = 𝑉𝑉 �𝑅𝑉𝑉𝑉

𝑅 + 𝑅𝑉𝑉𝑉�

Once the values were substituted the equation looked like this:

0.3 = 3.3 �26𝑘

𝑅 + 26𝑘�

Using basic algebraic principle, you can easily solve for R which is 260K. We opted to

use a resistor with the value of 270k because it could be provided for free through the

ECE 480 lab.

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