1. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Team members Derek Lindberg Sean McDevitt Nick Ciocco Eric Hoffman Chris Browne Wireless Nothing Critical Design Review

2. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Two-way wireless communication between two separate motorcyclists. Low-power, low-profile design for easy installation/integration inside helmet. Adjustable volume, microphone gain, and channel selection. Restricted access to broadcasted audio. Project Overview

3. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots High Level Concept Short range RF Long range RF

4. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Initial Set-backs – Wireless Transceiver nRF24Z1 – Only a point to point streaming device. Not capable of handling TDD (time division duplexing) or FDD (frequency division duplexing). nRF24L01 – Great device, but not yet in full production Possible future use if breakout boards available nRF2401a – Current selection Fastest data-rate for a “true” transceiver Requires additional packet handling

5. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Initial Set-backs - Codec TI TLV320AIC28 I2C control format QFN package TI TLV320AIC33 Not available (just released) QFN package Xemics XE3006 Audio format is standard serial (not I2S) Not available in quantities under 62 TI TLV320AIC23B Available with all needed features SOP package 1 23 4

6. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots DAC Codec ADC Codec Microcontroller MicrophoneHeadphones Transceiver System Block Diagram - Headset I2S SPI

7. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Block Diagram – Basestation Microcontroller Basestation to other motorcyclist transceiver SPI Bus Basestation to helmet transceiver Serves as a booster for the helmet’s voice communications Handles channel allocation for slave headset

8. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Transceiver(s) Microcontroller 48kB Flash, 1024B RAM Extremely-low power 330uA active 1.1uA standby mode Dual 12bit DACs SPI interface in hardware 48 IO pins RS232 Interface via MAX3222 transceiver HANDLING SPI/I2S —— SPI —— Audio Codec Microcontroller – MSP430F1611

9. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Timing Diagram I2S/SPI

10. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Main System (Base Station) Schematic

11. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Transceiver 2.4 GHz operating frequency Low cost Low power 1Mbit/s ShockBurst Data Rate Low on-air time SPI Communication Dual-channel receiver (2Mbit/s) Simple PCB antenna —— SPI —— Microcontroller Receiving Transceiver Transceiver – nRF2401a

12. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Microphone Microcontroller Headphones Audio Codec Convert between analog and I 2 S Low power/Low cost High quality 16 bit sound DAC and ADC in single chip for simplicity Integrated gain control, volume control and speaker drivers if possible SPI control from Microcontroller ——I2S—— ——Analog—— Audio Codec – TLV320AIC23B

13. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Current Project Plan – Divide and Conquer Printed circuit board tasks Assemble Test and debug Begin second PCB revision Dev. board tasks Establish communication between transceivers Experiment with data rate limitations using Test maximum range and acceptable error rates.

14. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots MSP430F1611 Dev. Board with nRF2401a Prototype Base Station Provides test bed for extended functionality

15. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Printed Circuit Board Rev. 1

16. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Risks Difficulty making SPI communicate with I 2 S High speed data rate and clock rate Unknown transmitter packet error rate at 1Mbps Difficulty with QFN package type (reflow) Wireless protocol complexity may be underestimated

17. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Backup Plan  Use MSP430F1611 internal ADC/DAC SPI communication with I2S is removed  Use lower data rate for transceiver Voice still possible and known implementation at this data rate exist  Out-source transceiver assembly or use breakout boards from SparkFun

18. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Division of Labor Group Responsibilities Documentation, system development, integration, system testing Team MembersResponsibility Derek LindbergHardware layout and assembly, firmware programming Sean McDevittAntenna and Transceiver design Nick CioccoTransceiver design and PCB layout overview Eric HoffmanHardware layout and assembly, firmware programming Chris BrowneAssembly firmware programming, hardware integration

19. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Project Timeline

20. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Milestone 1 – March 23 rd Printed circuit board assembled, tested, and debugged Microcontroller communicating with all peripherals Simple high-speed data transmission between two transceivers on development board Determine if addition of portable audio is feasible

21. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Milestone 2 – April 20 th Preliminary voice communication up and running Microphone in and headphone out Base station to headset acquisition Preliminary protocol functionality Preliminary portable audio capability, pending Milestone 1

22. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Budget/Final Parts List Parts (per board)Cost Active Components$60.00 Misc. Parts (all passive components)$5.00 Misc. Connectors$5.00 Total$70.00 Total (est. qty. 100)$30.00 Budget BreakdownQtyCost Base Stations2 boards$140.00 Headset8 boards$560.00 PCB2 revs$300.00 Total--$1,000.00

23. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots Questions ?

24. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots State Diagram – Headset Init Base Station Search Idle Rx Tx Always Packet Tx Base Station Found Wait Packet Decoded Packet Received Wake-On-Voice

25. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Critical Design ReviewHandmade by Robots State Diagram – Base Station Init Headset Search Idle Local Audio Remote Tx/Rx Voice Timeout Voice Detected Always Voice Timeout w/o Audio Headset Found Wait No Audio Present Audio Device Present Headset Lost