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

2. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots Two-way wireless communication between to separate motorcycles. One-way wireless CD quality audio streaming from a portable device’s audio jack. Adjustable volume, microphone gain, and channel selection. Restricted access to broadcasted audio. Modular implementation of a wireless communication and audio listening device What is this Device?

3. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots High Level Concept Short range RF Long Range RF

4. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots DAC Codec ADC Codec Microcontroller MicrophoneHeadphones Transceiver Functional Block Diagram - Headset I2CI2C I2SI2S I2SI2S I 2 C Bus

5. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots ADC/DAC – OR – Transceiver Transceiver Single Chip Wireless Transceiver (nRF24Z1) 2.4 GHz operating frequency Low cost Low power High-fidelity sound (16-bit) Channel selection Integrated control channel 1Mbit/s – 4Mbit/s Data Rate I 2 S or S/PDIF Audio Input (16bit) SPI or I 2 C Integrated Frequency Hopping Scheme —— I 2 S —— —— I 2 C —— Microcontroller Receiving Transceiver

6. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots Size ~ 23cm x 1.5mm 2.4 GHz Printed Monopole Size ~ 12mm x 20mm 2.4 GHz Printed Whip Monopole 2.4 GHz Chip Antennas Size ~ Tiny < 1cm 2 Reduced gain from reduced size Antenna Considerations

7. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots DAC Codec ADC Codec Microcontroller MicrophoneHeadphones Transceiver Functional Block Diagram – Headset, DAC/ADC I2CI2C I2SI2S I2SI2S I 2 C Bus

8. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots Microphone Microcontroller HeadphonesMP3 Player DAC / ADC Single Chip DAC/ADC I 2 S 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 I 2 S communication to Transceiver I 2 C control from Microcontroller ——I 2 S—— Transceiver ——I 2 C—— ——Analog—— DAC/ADC

9. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots DAC Codec ADC Codec Microcontroller MicrophoneHeadphones Transceiver Functional Block Diagram - uC I2CI2C I2SI2S I2SI2S I 2 C Bus

10. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots Transceiver(s) Microcontroller Primary Functions Timing Control power consumption User feedback (tones, battery level) Process user input (buttons) Microcontroller (MSP430F156) Features 24kB Flash, 1024B RAM Very-low power 330uA active 1.1uA standby mode 12bit DAC I 2 C and SPI interfaces in hardware 48 IO pins Overkill, but we will never have to worry about exceeding code space or having too few IO pins during dev. —— I 2 C —— ADC/DAC Microcontroller

11. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade 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

12. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots High Level Concept Short range RF Long Range RF

13. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots Functional Block Diagram – Base Station Microcontroller Base Station to Other motorcyclist Transceiver I2CI2C I 2 C/I 2 S Bus Base Station to Audio Device Transceiver Base Station to Helmet Transceiver Serves as a booster for the helmet’s voice communications Receives voice from helmet and retransmits with larger gain Receives voice communication from other motorcyclist(s) and transmits them to the helmet Given input from helmet, switches between voice communication and music

14. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade 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

15. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots High Level Concept Short range RF Long Range RF

16. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots Functional Block Diagram - Media Device ADC Codec Microcontroller Media Device Transceiver Analog I2CI2C I2SI2S I 2 C Bus Transmits streaming wireless audio from a portable device such as an mp3 player Audio is played back in the helmet Has a lower priority than voice comm Same PCB as Helmet (headphone portion left unpopulated) Simplifies Design Single circuit to debug

17. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots State Diagram – Media Device Init Base Station Search Idle Remote Tx Always Audio Timeout Base Station Found Wait Audio Levels Present

18. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots Highly Modular Design uC Audio Codec Audio Codec uC Tx/Rx uC Tx/Rx Audio Codec Base StationHeadphone/MicWireless Audio Transmitter Each component is composed of several re-useable modules We only need to do low-level design and testing once

19. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots Division of Labor Group Responsibilities Documentation, system development, integration, system testing, and documentation Team members Responsibility Derek Lindberg Hardware layout and assembly, firmware programming Sean McDevitt Antenna and Transceiver design Nick Ciocco Transceiver design and PCB layout overview Eric Hoffman Hardware layout and assembly, firmware programming Chris Browne Assembly firmware programming, hardware integration

20. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots Project Timeline

21. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots Risks and Contingencies Risks Unfamiliar Interfaces and Devices I 2 C/S, Transceiver, Codec Difficulty controlling codec/transceiver w/ uC Limited transmit range / Problems w/ interfering devices Lead time on components / Availability problems Difficulty getting RF link working (RF protocol) Compliance with FCC regulations Prevention Help from TAs, Manufacturers, Dev Boards Nordic, Texas Instruments May be short range for Expo Ordering samples far ahead of time Use Nordic dev board Will ignore them

22. ECEN 4610 Spring 2006 Hands-Free Low-Profile Wireless Radio Preliminary Design Review Handmade by Robots Questions ?