Team: Wireless Nothing

1. Team: Wireless Nothing Preliminary Design Review Handmade by Robots

2. What is this Device? • 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 Handmade by Robots

3. High Level Concept Short range RF Long Range RF Short range RF Handmade by Robots

4. Functional Block Diagram - Headset Microcontroller Microphone Headphones I2C I2C Bus ADC Codec DAC Codec I2S I2S Transceiver Handmade by Robots

5. Transceiver ADC/DAC – OR – Transceiver ——I2S—— Receiving Transceiver Single Chip Wireless Transceiver (nRF24Z1) Transceiver • 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 • I2S or S/PDIF Audio Input (16bit) • SPI or I2C • Integrated Frequency Hopping Scheme ——I2C—— Microcontroller Handmade by Robots

6. Antenna Considerations 2.4 GHz Printed Monopole 2.4 GHz Chip Antennas • Size ~ 23cm x 1.5mm • Size ~ Tiny < 1cm2 • Reduced gain from reduced size 2.4 GHz Printed Whip Monopole • Size ~ 12mm x 20mm Handmade by Robots

7. Functional Block Diagram – Headset, DAC/ADC Microcontroller Microphone Headphones I2C I2C Bus ADC Codec DAC Codec I2S I2S Transceiver Handmade by Robots

8. DAC/ADC Microphone Headphones MP3 Player Single Chip DAC/ADC I2S Codec ——Analog—— • Convert between analog and I2S • 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 • I2S communication to Transceiver • I2C control from Microcontroller DAC / ADC ——I2C—— ——I2S—— Microcontroller Transceiver Handmade by Robots

9. Functional Block Diagram - uC Microcontroller Microphone Headphones I2C I2C Bus ADC Codec DAC Codec I2S I2S Transceiver Handmade by Robots

10. 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 • I2C 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. Microcontroller ——I2C—— Transceiver(s) ADC/DAC Handmade by Robots

11. State Diagram – Headset Tx Packet Tx Always Base Station Found Wake-On-Voice Init Base Station Search Idle Wait Packet Received Wait Packet Decoded Rx Handmade by Robots

12. High Level Concept Short range RF Long Range RF Short range RF Handmade by Robots

13. Functional Block Diagram – Base Station Microcontroller • 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 I2C Base Station to Helmet Transceiver Base Station to Audio Device Transceiver I2C/I2S Bus Base Station to Other motorcyclist Transceiver Handmade by Robots

14. State Diagram – Base Station Remote Tx/Rx Voice Timeout w/o Audio Always Headset Found Audio Device Present Init Headset Search Idle Voice Detected Voice Timeout Audio Device Present Wait Wait No Audio Present Local Audio Handmade by Robots

15. High Level Concept Short range RF Long Range RF Short range RF Handmade by Robots

16. Functional Block Diagram - Media Device • 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 Microcontroller Media Device Analog I2C ADC Codec I2C Bus I2S Transceiver Handmade by Robots

17. State Diagram – Media Device Always Base Station Found Audio Levels Present Init Base Station Search Idle Remote Tx Wait Wait Audio Timeout Handmade by Robots

18. Highly Modular Design Wireless Audio Transmitter Base Station Headphone/Mic Audio Codec Tx/Rx Audio Codec Tx/Rx uC Tx/Rx uC uC Tx/Rx Tx/Rx Audio Codec • Each component is composed of several re-useable modules • We only need to do low-level design and testing once Handmade by Robots

19. Division of Labor Group Responsibilities • Documentation, system development, integration, system testing, and documentation Handmade by Robots

20. Project Timeline Handmade by Robots

21. Risks and Contingencies Risks Prevention • Unfamiliar Interfaces and Devices • I2C/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 • 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 Handmade by Robots

22. Questions ? Handmade by Robots