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Rotary Racer Telemetry

Introduction

Over the years the Rotary Racer car has been developed and recently has had a Computer added to monitor and log various cars parameters. Unfortunately we can only look at these parameters after the race. We It would be good to be able to see these parameters during a race and be able to change them as required. So two way communications with the car is desirable. Also we have no communication with the driver during the race and so adding a two way communication system would be good.

The races are carried out on full sized race circuits which cover a large area with intervening hills and involve moving cars so radio communications are difficult. The team will probably need to play with few technologies before a reliable system is found. Funds are tight as we only have small sums of money kindly donated by sponsors. The main methods we think we could use are:

Lowpower Zigbee transponders

These low power units would connect to our Car Computer and a members laptop computer at the pits. They may only operate when the car is near the pits, but the data rate should be sufficient to burst the data during this period. They are low power and free to operate. The cost would be about £180.00.

Use Walkie Talkies

Walkie talkies with headset connectors and VOX technology could be used. A simple bit of electronics could generate the necessary signals to send over the speach bandwidth.

Use Mobile Phone GPRS technology

This would use two Mobile phone based GPRS units to convey data between the car and the pits. Assuming there is GPRS coverage at the circuit this should work all around the circuit. One of the issues is if GPRS to GRPS station communications is allowed on the mobile phone network in question and also the cost of continuous GPRS usage. This would cost around: £260.00 plus the cost of GPRS usage. The power usage may be an issue unless we can use a separate battery for the race. The cost of GPRS usage would probably be prohibitive.

Use Other Radio Transponder Technologies

There are other radio communications technologies available, including 433MHz systems and perhaps using the 27 MHz radio control/CB band. We should investigate these. I suspect that there cost would be similar to the previously mentioned systems.

Communications with driver

If the data communication system has enough bandwidth, voice communications could be carried out over the data channel. Otherwise we could simply use two free band two way radios that are generally available situated in high places on the car and at the pits. We would need to purchase radios with headset interface (including VOX) and 6 motorcycle headsets for the team. The headsets would be installed inside the helmets. This would cost around: £250.00.

Car Computer

The car computer measues various parameters of the cars operation and can generate a 32 Byte packet of information every second. The information available is given in the Car Computers manual. The maximum bit rate of this data is hence 8 * 32 = 256 bits/second. We can lower this by sending the data packets less frequently.

Development Information

Fetaures:

  • Be able to view the Car Computers parameters during a race.
  • Be able to change some of the Car Computers parameters during a race.

Issues include:

  • Range: What range can we expect.

More Information

More recent info

Car Computer Information

Zigbee Modules:

GPRS Modules:

Helmet microphone and speaker kits: