Knight BrightGroup #1:

Robin AdamsNathan Doran

Tyler Hemp-HansenShaun Sontos

What is “Knight Bright”?

• Knight Bright is a 2-dimensional, 100 (10x10) pixel tabletop interactive LED (RGB) gaming system.

• The primary motivation behind this project is to develop a fun, easy to use, user-programmable interactive tabletop.

Specifications and Requirements

Dimensions 20” x 20” x 6”

Weight Less than 20 lb.

Resolution 10 x 10

Color Depth 8-bit minimum color pallet

Communication Wireless to Device (range < 10 m)

Memory Must store at least 3 on-board games (approximately 30KB)

Power < 200 W

Project Goals• Use a (secondary) MCU to control an array of LEDs via LED PWM drivers• Transmit the output of an IR sensor circuit into a (secondary) MCU• Establish serial communication protocol that enables reliable

communication between MCUs• Successfully integrate Bluetooth capabilities into the project• Develop an mobile peripheral application• Successfully integrate user programmable and memory expansion

capability• Develop a host programming GUI environment

Games

Game Programming• Desktop programmer GUI can make games and

upload them to the board– Simplified C compiler

• Program stored as files on a SD card. Each character represents a assembly command or modifier specific to this application– Large storage space for many programs

Board Programmer

Compiler

Lexical Analyzer

InputProgram

Lexeme List

Parser

Code Generator

Output Machine

Code

Symbol Table

Machine Code Output

Knight Bright Simulator

Simulator to test games without hardware

Critical for development while assembling and debugging the hardware

Microcontroller

• ATmega328P• 3 Microcontrollers

– Primary microcontroller – Fetches and executes instructions from the program file on the SD card. Directs actions to the other microcontrollers.

– Display microcontroller – Executes commands related to LEDs and graphics

– Input microcontroller – Addresses and monitors IR sensors. Reports current status back to primary microcontroller

LED Requirements

• Diffused common cathode LED bulbs• Maximum driving current of 30 mA

per bulb• LED Control Techniques

– PWM (S/W or H/W)• Total of 300 LED lines must be sinked• Ultimately, a dedicated LED driver IC

was used to drive the LED PWM

5mm Common Anode Diffused RGB LED

Selecting the LED DriverModel Name TLC5941 TLC5940 STP16CP05MT

RPCA9922

Current supply(max)

80 mA 

60 mA (< 3.6 V) 120 mA (> 3.6 V)

100 mA 

60 mA 

Voltage supply (input)

3 to 5.5 V 3 to 5.5 V 3 to 5.5 V 3.3 to 5.5 V

Voltage supply (out, all channels)

17 V 17 V 20 V 6 V

Communication Serial (TTL) Serial (TTL) Serial (TTL) Serial (TTL)Data Transfer rate 30 MHz 30 MHz 30 MHz 25 MHzChannels 16 16 16 8Cost $1.80/per unit $2.21/per unit $4.32/per unit $0.49/per unitFeatures (or lack thereof)

• PWM• 12-bit

Grayscaling • 6-bit Dot

Correction

• PWM• 12-bit Grayscaling

• 6-bit Dot

Correction (EEPROM storable)

• No H/W PWM •  No H/W PWM

TLC5941/5940TLC5941 LED Driver

16 channels

80 mA current supply(max)

30 MHz data transfer rate

12-bit Grayscale PWM

6-bit DOT Correction

• TLC5941 (TI LED driver)– Low cost– Ease of use– Proliferated software support– EEPROM not necessary

Human eye only requires ~50-60 Hz, and ~33% duty cycle for smooth pulses.

212 = 4096 levels

5V

LED Driver (TLC5941)

012121314 1110 9 8 7 6 5 4 3

• Each TLC5941 IC drives 5 RGB LEDs.

• All TLC5941 ICs access their respective LED lines on the board horizontally.

• The reference base for this 5 LED row addressing scheme begins at the bottom right corner.

Driver 1Driver 2

Driver 3Driver 4

Driver 6 Driver 5

……

LED Driver Control

DriverMCU

5:32 Decoder

LED Driver

LED Driver

LED Driver

LED Driver

LED Driver

LED Driver

LED Driver

LED Driver

LED Driver

LED Driver

LED Driver

LED Driver

LED Driver

LED Driver

LED Driver

LED Driver

LED Driver

LED Driver

LED Driver

A0A1A2A3A4

5:32 Decoder selects 20 Addresses(0 – 19)

to XLAT pins

MODE,SIN, SCLK,

BLANK,GSCLK

All Common to MCU

LED Driver

Led Driver Addressing

PCB and Wood Frame Layout

2 Layer Frame Layout• Top Layer: IR circuits• Bottom Layer: Four

(5x5) Pixel Circuit Corner sections, PCB, and PSU

Top Layer 100 Pixel Circuits

Bottom Layer Corner sections,

PCB, and PSU

Sensor Cell Design

• General requirements– Each sensor must detect an object in front of the cell to

provide input to the device– Each Cell must contain a RGB LED to provide output

• Primary Considerations– An intelligent design approach must be used to minimize

the number of microcontroller pins needed for user interfacing

– The group should also utilize cost efficient methods to meet the requirements

Sensor Array Design

Sensor circuit &

Sensor circuit &

Sensor circuit &

Sensor circuit &

Row Select Column Select

Return to MCU

QED123 IR Light Emitting Diode

λ 880nm

Material GaAsPackage type T-1 ¾ (5mm lens

diameter)Emission angle

16°

Output power

High

Matched photo-sensor

QSD123

QSD123 IR (NPN)PHOTOTRANSISTOR

Daylight Filter

Material SiliconPackage Type: T-1 ¾ (5mm lens

diameter)Reception angle

24°

Sensitivity HighMatched Emitter:

QED12X

Sensor Circuit Design

74HCT08 Quad 2-input AND Gate Philips SemiconductorHigh-speed Si-gate CMOS devicePackage DP14 Propagation delay 6ns 2 to 6 V 0 to Vcc – 1.5 V (Typical 1.6V) 0.8 (Typical 1.2) Vcc (Typical 4.4V) = 20mA

Sensor Circuit Design

• Innovative Solutions– Move Row/Column

pull down resistors to Decoder output

– Voltage divider – Jump output ‘A’ to

input to ‘B’ for 3 input gate

– Diode added to return line to prevent back feeding into and gates

Pixel Circuit Design

Wireless Method• For use with an mobile device, the most prevalent

methods are Bluetooth and Wi-Fi• Other wireless technologies were tossed out because of

the added cost of an adapter to the mobile device

• In the end, Wi-Fi is simply overkill for the application

Technology Bluetooth Wi-Fi

Range 20m 150m

Power Consumption ~99mW ~594mW

Data Rate 300Kbps ~30Mbps

Cost $15.95 $30.10

Bluetooth Module: RN42-XV

Manufacture Roving Networks

Price $20.95

Supply Voltage 3.0 – 3.6 V

Default Bluetooth Profile

Serial Port Profile(SPP)

Pins 20 pins (only 5 of which will be used)

Speed 9600 Baud

Mobile Application

Platform:• Android has a familiar

environment with Java Eclipse

• Vast libraries, specifically one for Bluetooth usage

• Open source and many support tutorials and explanations

• Easy drag and drop style GUI creator

Features:• The user is able to select

what program is running on Knight Bright

• For certain programs the App will be used as a controller

• Text input from the App to the device

• Grid for one to one control

Mobile Application (Protocol)Text Controller Grid Program

Select

Hello World!

Up (#u) Row/Col TicTacToe ($0)

(del)Hello World!

Down (#d) 00 Battleship ($1)

Left (#l) 01 Tetris ($2)

Right (#r) 02 …

Select (#s) 03… etc …

User

Connect Device

Scan for New Device

Connect to Existing Pair

Access Menu

Select Prgram

Disconnect

Exit Applicaion

Touch Grid

Text Input

Controller Input

includeinclude

include

include

include

Mobile Application (Use Case Diagram)

+goToGrid()+goToCon()+goToText()+getState()+connect()

-Grid : Button-Con : Button-Text : Button-Menu : Button-connect : Button

Main+setState()+getState()+connect()+connected()+stop()+write(in out : byte)

-myAdapter : BluetoothAdapter-myState : int-myAccept-myConnect-myConnected

BluetoothChatService

+send()-100 Buttons : Button

Grid

+send()

-Up : ImageButton-Down : ImageButton-Left : ImageButton-Right : ImageButton-Select : Button

Controller

+send()

-sendButton : Button-inputText : ListView-outputText : EditText

Text Input

Activity

«extends»

«extends»

«extends»

«extends»

«goToGrid()»

«goToCon()»

«goToText()»

«send()»

«send()»

«send()»

Mobile Application (Class Diagram)

Component ComponentMax Current(mA)

Number present Power consumption per device (mW)

Power Consumed (W)

Microcontroller 9 2 45 0.09

Led Driver ---------- 19 2456 46.66

Bluetooth Device 30 1 150 0.15

Decoders ---------- 3 TBD TBD

USB 21 2 105 .21

RGB LED 60 100 300 30.00

IR Emitter 20 100 100 10.00

IR Detector 20 100 100 10.00

And Gate ---------- 100 500 50.00

Total Calculated

Actual

147.11

20

Power Consumption

TDK-Lambda LS200-5

Note: Careful component selection lead to a need for only 1 voltage regulation device for the Bluetooth chip (.05 x 1.7 = .085 Watts)

Power Supply Type SwitchingInput voltage 85 – 263 VACInput Frequency 47-63 HzOutput voltage 5 VDCMax current 40 ATypical Efficiency 72- 75 %Enclosed fan YesOvervoltage protection 5.75 – 6.75 VDCOvercurrent protection 105% nominal peakOver Temperature Protection YesSize 7.8 x 3.9 x 1.6”Cost $49.52

• By designing isolated regions the board was able to be tested one quarter at a time

• A ‘change of state’ test program was generated which included all basic colors and a response to positive return

Testing

Part Price Quantity Total

Microcontroller $1.62 3 $4.86

TLC5941 $1.80 19 $34.20

RN-42(one with breakout) $21.50 2 $43.00

Power Supply $49.52 1 $49.52

Resistors $0.01 1000 $10.00

Diodes $0.03 100 $3.00

Decoders (4:16) $1.52 4 $6.08

AND Gates $0.26 100 $26.00

IR Detectors $0.43 100 $43.00

IR Emitters $0.35 100 $35.00

RGB Light Emitting Diodes $0.24 150 $35.00

PCB $83.00 1 $83.00

Construction Supplies $55.00 ----- $55

Wire $5.00 / 100 ft 1000 ft $50

Total     $477.66

Budget

Project Robin Nathan Tyler Shaun

Firmware, Compiler, game logic, GUI

X

Android App Development X

Bluetooth X X

Sensor Cell Design X

Sensor Cell Production X X X

PCB Design X

Memory Expansion Integration X

Soldering X X X

Device Construction X X

Distribution of Work

Questions?