Bi-Directional RF Data Communication

1. Bi-Directional RF Data Communication A Robot Control Device Team BDRFC

2. Team BDRFC Members • Matthew Merican – Team Leader • Varun Jain – Assistant Leader • Andrew Gibbons - Secretary • Trevor Damyan - Treasurer • Noel Smith – Document Coordinator Matthew Merican

3. Summary of Presentation • Overview • Design Plan • Requirements • Design Concepts • Block Diagram of Design • Design Specifics • Planned Activity • Budget • Deliverables Matthew Merican

4. Project Summary To design and implement a wireless RS232 serial communication device. This device will be used in EGR286 to communicate with the student’s robots. This device will allow wireless communication between four different robots being used at the same time. Matthew Merican

5. Overview • Wireless RS232 communication device that communicates over a range of 100 feet with a baud rate of at least 2.4 Kbits/second. • We will be using the standard com port through a RF link, to communicate with the remote transceiver. • We need four independent communication channels so that four robots can be controlled at the same time. • No licensing required for the use of this product. • Frequency division or time division can be used to prevent cross communication between the four different robots. • A stable supplier for replacement parts needs to be found. • The packaging needs to be durable and resistant to the natural elements. Matthew Merican

6. Design Plan • Research • Conduct research into different types of systems that can be used. • Research of specific configuration of the chosen system. • Derive Requirements • Determine Design to Implement • Chosen Design: Serial Transceiver Link • Build and Test (future design phase) • Demonstrate (future design phase) Noel Smith

7. Requirements • Changed • Dimensions: 2” x 2” x 0.5” maximum • Weight: 4 oz. • Operating Temperature: 10° to 30° C • New • Should be able to withstand a drop of 3 ft. • Product will be tested to verify range of 100 ft., withstand 3 ft. drop as well as shock, and to make sure that it is water resistant. Noel Smith

8. Transceiver Design • Pro • Off the shelf components • RS-232 compatible • Easily interfaced with other components • Inexpensive • Upgradeable range and performance • Con • Error checking not necessarily built in • External filters and amplifiers needed Noel Smith

9. Wireless LAN Design • Pro • Built in error checking • Specific IP Addresses: prevent interference from other signals • Con • Limited range capabilities • Network traffic will reduce performance • Interfacing and programming difficulties on robot end • Controller needed for robot • Replacement parts are expensive Noel Smith

10. Wireless LAN vs. Transceiver Wireless LAN • Need to learn how to interface PCMCIA card with the serial port of the robot • Difficulty programming PCMCIA controller • Difficulty in replacing parts, since companies upgrade and change products too rapidly Transceiver • Many transceivers easily interface with serial ports • Only need to develop a driver to meet technical specifications of the transceiver • Developed as integrated circuits, so easy to find replacements Noel Smith

11. Proposed Design Concept We will be designing a RF wireless serial link in the range of 400Mhz to 2.4Ghz. One end will be attached to the robot powered by the robots power supply or a small battery. The other end will be attached to a computer. We will design software/drivers to interface the computer with the serial link. The serial link will function as a wireless serial cable. Trevor Damyan

12. Block Diagram of Design Trevor Damyan

13. Summary of Block Diagram • Command is sent from the com port to the RF Transmitter • Signal is amplified by power amplifier and antenna. • Signal is transmitted to the robot. • Signal passes through a low noise amplifier (LNA) and filter to amplify and eliminate noise/interference. • Signal is processed by the receiver. • Robot receives processed serial information. • Process is reversed for communication from robot to computer. Trevor Damyan

14. Component Selection • Needed Components • Transceiver • Power Amplifier, LNA • Antenna • Packaging • Filtering Hardware Trevor Damyan

15. Design Specifics • Amplifier, antenna • Filter Usage • Time Sharing vs. Frequency Division Andrew Gibbons

16. Filter Usage • To reduce static in the received transmission. Andrew Gibbons

17. Time Sharing vs. Frequency Division Time Sharing Frequency Division Andrew Gibbons

18. Planned Activity • Determine which transceiver to use. • Frequency (900 MHz, 1.8 GHz, or 2.4 GHz) • Bitrate (at least 2400 bps), channels (time or frequency division) • Hardware error checking • Research Filter Design • Noise/Interference filtering • Clean up signal Varun Jain

19. Planned Activity • Derive Link Budget • Needed power amplification • Antenna (type, gain) • Bandwidth, bit-rate • Schematics • Transceiver, power amplifiers, filter designs • Top-level circuit • Analysis and Simulation • Testing using simulated serial data and measuring on oscilloscopes Varun Jain

20. Planned Budget Varun Jain

21. Budget • Budget Goal: $200 per unit • Budget is estimated • Some parts can be built cheaper than buying an off-the-shelf product • Highest cost for each component was chosen • Purchases will be made by client Varun Jain

22. Deliverables Varun Jain