1. ECE477 Midterm Design Review: Team # 6 Plays Tanks
Michael Loh, Andres Avila, Andres Castillo, and Sung-Yeon Choi

2. Outline Project Overview PSSCs Major Components Block Diagram
Packaging Design
Electrical Schematic
PCB Layout
Prototyping Progress
Software Development Status
Project Timeline
Questions

3. Project Overview
Twitch Plays Tanks is a game played between two RC tanks controlled by either app or live command input from a Twitch feed. The goal of each player is to score enough hits on his opponent to win.
Commands are centrally processed using a Raspberry Pi
Processed commands are sent to the tanks using the ZigBee protocol
Tank will have an IP camera installed for a first-person view to stream video to a Twitch feed and Android app.

4. PSSCs
An ability to receive and send commands between MSP430 and Raspberry Pi through ZigBee
An ability to communicate between Android app and Raspberry Pi through Bluetooth
An ability to have Raspberry Pi parse commands from Twitch IRC chat
An ability to use IR receiver and transmitter as hit detection system
An ability to have the tank translate sent commands into accurate motor movement

5. Component Raspberry pi 2
Description:
Microprocessor used as control unit.
Bridge of communication between Android phones and Twitch to tank microcontrollers.
Stream video feed to Twitch stream.
Relevant Specifications:
900 MHz quad-core ARM Cortex-A7 CPU
1 GB RAM
4 USB ports, 40 GPIO pins
Ethernet and HDMI ports
Micro SD card slot

6. Component MSP430G2553 Description: Relevant Specifications:
Microcontroller used to control tank.
Controls tank movement, IR hit detection and XBEE communication with the Raspberry Pi.
Relevant Specifications:
16-Bit RISC Architecture, 16 MHz clock
16 KB Flash memory, 512 B RAM
16 GPIO pins, 2 USCI pins
2 16-Bit timers
8 ADC10 channels

7. Component Xbee series 1 – 1mw
Description:
Zigbee wireless communication interface used for MSP430 and Raspberry Pi communication.
Relevant Specifications:
3.3 50mA
250 kbps max data rate
300 ft. range
UART communication interface

8. Component TSOP38238 Description: Relevant Specifications:
IR receiver module used for detecting IR emission from the other tank.
Relevant Specifications:
38 KHz carrier frequency
45 m typical transmission distance
±45 ° at half transmission distance
2.5 – 5.5 V supply

9. Component TSAL6200 Description: Relevant Specifications:
IR emitting diode used for signaling the IR receiver from the other tank.
Relevant Specifications:
200 5 V(38 KHz)
±17 ° at half intensity

10. Component DC Motor/h-Bridge
Description:
Used for controlling tank movement. The possible movements will be forward, reverse, turn right and turn left.
Relevant Specifications:
Motor 5 V, 300 mA
~ 600 mA stall current
5 V H-Bridge operating voltage

11. Component LM1117-N Description: Relevant Specifications:
Linear voltage regulators used for converting 7.4 V to ~3 V and ~5 V.
Relevant Specifications:
15 V max input voltage
125 °C max junction temperature
93 °C/W thermal resistance with heat sink
1.08 W max power dissipation

12. Component Toughsty ip camera
Description:
IP camera connected to each tank. Streams live video to Twitch feed.
Relevant Specifications:
Rechargeable battery built-in
50 min battery life
25 min/GB memory consumption
Up to 32 GB SD card

13. Component pi cam module
Description:
Camera connected to Raspberry Pi that will stream an eagle eye view of the arena to Twitch.
Relevant Specifications:
Supports 1080p30, 720p60 and 640x480p60/90 video
Uses dedicated CSI interface in Raspberry Pi 2

14. Component Ni-MH RC Battery
Description:
Rechargeable Battery used as tank power supply.
4x more capacity than stock tank battery.
Relevant Specifications:
7.2 V/2000 mAh
89 x 50 x 16 mm^3

15. Block Diagram

16. Packaging Design Tank and PCB
-Tank chassis is premade and taken from an existing RC tank product. PCB will sit inside the bottom well of the tank chassis
-The NiMH battery pack will sit in a compartment underneath
-The IP camera will glued into a cut-out slot in the front of the tank chassis
Battery pack - 84 x 50 x 15mm
Battery compartment x 57 x 18mm
PCB x 75 x 1.6mm
IP camera – 52 x 22 x 22mm
Tank w/o turret x 148 x 48mm

17. Packaging Design Arena and Control Module
-Tank arena will be constructed of cardboard and wood. Detachable wood fences attach to Velcro placements around the cardboard field.
-Cardboard field consists of Velcro circles 6 cm in diameter for placement of simple field obstacles.
Tank Arena x 100 x 7cm
Control Module – 12.7 x 6.3 x 5cm
Raspberry Pi will be inside a basic plastic enclosure

18. Electrical Schematic Overview

19. Electrical Schematic POWER
Power Considerations:
Linear Regulators with heat sinks to step down voltage to 5V and 3.3V
Microcontroller Current Draw: 500mA
IR Sensor Current Draw: 500 mA
Motors Current Draw: 3 1 A.

20. Electrical Schematic H-Bridge ICs
Power Considerations:
Will control 5V, 1A current draw
Require 5V to operate ICs

21. Electrical Schematic IR Shooting Mechanism
Considerations:
5V Supplied to IR sensor.
Controlled by 2N2222
5V Supplied to IR receivers (active low)
IR Receivers optimal transmission at ±30 degrees. 6 required for full 360 coverage
Logic cascaded through 3 NAND Gates and 2 Inverters.

22. Electrical Schematic ZigBee Xbee module
Considerations:
3.3V required to operate
Communicates through UART
Direct connection to microcontroller, receives data from command center (Rasp. Pi)

23. Electrical Schematic MSP430G2553
Considerations:
MSP430 Microcontroller
3.3V required to operate
Brains of the tank. Talks to motor, IR Sensor, IR Receiver and Zigbee

24. PCB Layout Overview

25. PCB Layout POWER

26. PCB Layout H-Bridges and MOtors

27. PCB Layout IR Receiver & Transmitter

28. PCB Layout XBEE MODULE

29. PCB Layout MSP430

30. Prototyping Progress MSP430:
IR hit detection system has been implemented successfully.
Motors have been tested with a power supply, but not directly with the microcontroller.
XBEE communication is the next step to be tested once the programmer arrives.

31. Prototyping Progress Pi: Libraries needed have been installed.
One IP camera has been tested and has proprietary software that doesn’t allow video to be parsed. Therefore, another IP camera is being tested.
In the case that the other IP camera can’t be parsed, a Raspberry Pi Cam Module will be used.

32. Prototyping Progress Android App:
A simple App that displays text has been developed and tested on actual phone.
Bluetooth communication between Android App and Raspberry Pi is in development.
Video streaming for Android App has not been started.

33. Software Development Status
LEGEND
MSP430

34. Software Development Status
LEGEND
Raspberry Pi

35. Software Development Status
LEGEND
Android App

36. Software Development Status
LEGEND
Others

37. Project Timeline Finalize and order PCB Finish preliminary XBee work
Week 8
Week 9
Week 10
Week 11
Week 12
Finalize and order PCB
Finish preliminary XBee work
Build fully functional tank w/o app
Verify movement and firing capabilities
Finish work on XBee communications
Complete back-end functions of Android app
Solder PCB components
Integrate Raspi and Android app
Integrate Raspi with tanks
Week 13
Week 14
Week 15
Week 16
Testing of complete tank system
Finalize Twitch IRC parser
Thanksgiving Break
Further integration and testing
Completion of arena and showcase preparation
Showcase

38. Questions?