mid-semester presentation senior design i march 1, 2012 humidity-activated bathroom fan

Mid-Semester PresentationSenior Design IMarch 1, 2012

Humidity-Activated Bathroom Fan

Dontavius MorrissetteProgramming, Humidity

Sensor, Research

Dr. Mike MazzolaTeam Advisor

Chris FlemingTeam Technical Leader,

Power Circuit and Relaying

Brittany BerrymanTeam Manager, Power Circuit,

Wireless

Aaron PlunkettProgramming, Wireless,

Documents Lead, Website

John AyomProgramming, Wireless,

Team Members

• Problem

• Solution

• Constraints

– Technical

– Practical

• System Overview

• Approach

• Progress

• Timeline

• References

Presentation Overview

Problem and Solution

Issues with high humidity in the bathroom:

•Uncomfortable environment

•Structural damage

•Mold

Problem


• Two device system: wall (control) and ceiling module

• Calibrates and sets initial humidity settings for room

• After humidity exceeds 15% of initial calibration, the fan will turn on

• When room returns to the calibrated level, the fan will turn off

• Pushbutton will allow for user override

Solution

Technical and Practical Constraints

Name DescriptionHumidity Resistance The wireless ceiling module must be

able to withstand up to 100% humidity.

Activation Accuracy The HABF is activated when the humidity reaches ±5% of the user set level.

Wireless Transmission The system must have wireless range of at least 30 feet.

Supply Power The control module must operate from 120VAC/60Hz.

Device Power The ceiling module is battery operated with an estimated battery life of no less than 1 year.

Technical Constraints

Type Name Description

Manufacturability Size The HABF control module must fit within a single-gang electrical junction box.

Sustainability Maintenance The HABF system must require almost no user interaction or maintenance.

Practical Constraints

Manufacturability: Size

The HABF control module must not exceed 2-1/4"(W) x 3-3/4"(L) x 3-1/4"(D). This will allow the HABF to:

• Fit in to a typical single gang junction box• Replace existing fan switch


[1]

Sustainability: Maintenance

The HABF must require limited user interaction relating to device maintenance.


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System Overview

Control Module Ceiling Module

System Overview

Approach

Switching Comparison

Switching Comparison

How It Works:

[2]

Switching ComparisonProtocol Good Bad

Relay • Used for AC and DC circuits

• Sparking• Contacts wear

out easily

Triac • No operation noise• No moving parts to

wear out• No sparking

between contacts

• Only used for AC circuits

[2]

Triac

Part Gate Voltage (V) Price ($)

Q2004L3 1.3 .85

Q4008L4 2.25 2.26

Q4008R4 2.5 1.25

Q6015L5 2 1.95[3]

Humidity Sensor

Humidity Sensor

How It Works:

Capacitive:•Consists of a substrate on which a thin film of polymer or metal oxide is deposited between two conductive electrodes

Resistive:•Consists of metal electrodes deposited on a substrate (silicon, glass, ceramic)•Sensor absorbs water vapor and ionic functional groups are dissociated

[4]

Part Accuracy (%) ResponseTime (sec)

Output

HIH-5030 ±3 5 Linear Voltage

HIH-4030 ±3.5 5 Linear Voltage

HCH-1000-001 ±2 15 Capacitance

Humidity Sensor

[3]

Part Accuracy (%) ResponseTime (s)

Output

HIH-5030 ±3 5 Linear Voltage

HIH-4030 ±3.5 5 Linear Voltage

HCH-1000-001 ±2 15 Capacitance

Humidity Sensor

[3]

Wireless

Wireless Communication

How It Works:Protocol Power Range (m) Connection Time

802.11(Wifi)

High 50 to 100 3s to 5s

802.15.4(Zigbee)

Low 10 to 100 30ms

802.15(Bluetooth)

Medium 1 to 100 3s[5]

Wireless

Part Power Output (mW)

Sleep Current (µA)

Wake-Up Time

CC2530F32RHAT(Texas Instruments)

10 2µA 4µs

XB24-AWI-001(XBee)

1 <50 2ms

RF300(Synapse Wireless)

100 <16 1.2ms[6]

[3]

[3]

Progress and Timeline

Ceiling Module

1. Variable voltage is sent to the microcontroller

2. PIC receives analog voltage and sends value to XBee

3. XBee sends wireless data to the control module

Wall Module

1. XBee receives data from ceiling module

2. Microcontroller receives value from XBee

Output Data

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•Output from the control module microcontroller

•Proves successful wireless transmission of data from the ceiling module to the control module

Example Code

2/23/12

Triac Circuit

2/23/12

The Triac circuit utilizes a low DC voltage to turn switch 120 V AC.

Power Circuit

Timeline

[1] In techMall, February 16, 2012. Retrieved from http://biotechnological/Single-Gang-In-Wall-Junction-Box-S1-

18-W-1G-p/30780.htm

[2] “How Dimmer Switches Work,” in howstuffworks, February 18, 2012. Retrieved from http://home.howstuffworks.com/dimmer-switch3.htm

[3] In Digikey, February 17, 2012. Retrieved from http://www.digikey.com

[4] “Resistance Change Type Humidity Sensor Units with High-Accuracy Detection and Output Control,” in TDK, February 23, 2012. Retrieved from TDK.co.jp/tfl_e/sensor_actuator/CHS/index.html

[5] “How does ZigBee compare with other wireless standards?” in Software Technologies Group, February 24, 2012. Retrieved from stg.com/wireless/ZigBee_comp.html

[6] “SNAP Components: Synapse RF Engines,” in Synapse, February 24, 2012. Retrieved from synapse-wireless.com/snap-components/rf-engine#docs

References

Mid-Semester PresentationSenior Design IMarch 1, 2012


mid-semester presentation senior design i march 1, 2012 humidity-activated bathroom fan

Documents

high humidity

roomafter humidity

initial humidity settings

device powerthe ceiling

wireless range

supply powerthe control

activation accuracythe

device maintenance