Telemetry - Transceivers

[Gabriel Descamps]

Hello people:
We have a few problems with our transceivers. The datasheet specifies a top distance of about 600 ft., and they cut out all transmitting when the distance is about 75 ft. They were bought at www.okwelectronics.com (http://www.okwelectronics.com) . What kind of transcievers do you guys use? Is there a better brand or type of transceiver? Which is the best one? Where can I find more information about them and how they work? And what about the spread spectrum transceivers?
Thank you very much.

[Agent4573]

We use a unit from FreeWave(www.freewave.com), which is simply a wireless serial port. The transmitter end fits nicely inside our dash and the reciever end is powered by a spare battery on the sidelines. With our small 1.5 inch antenna we didn't have problems with lost data from the sidelines during any event. I believe we can get up to about 1000 feet with this small antenna and if you go with a larger antenna on the car we have estimated the range up to around 2500 feet or more. Our current setup is netting us about 700 Hz sampling rate through the transmitter, but we have linked our bottle neck to our software and not the hardware.

[GTmule]

Other than just being wizzy, what possible use is this in an autocross car?

in an F1 race, or at LeMans, great, but it's not as though you can bring 'er in to replace a failing ignition coil that you see show up on the telemetry.....

I don't get this one....? Why not just log it?

[Agent4573]

Our main reason for utilizing real time data transfer is basically to make sure the car isn't going to blow up. We have dummy lights on the car, but having the actual oil pressure, a/f ratio, coolant temp, etc displayed in front of you while the car in on the track gives us a nice fuzzy feeling knowing that we may be able to spot a problem before the dummy light alerts the driver. Everything else like telemetry, steering wheel angles, TPS, we just transmit and log for later analysis.

[B Lewis @ PE Engine Management]

A good set of wireless modems (like the Freewave units) and a set of wireless radios for voice commuication can also make fine tuning things like the engine ECU a snap. We have successfully used the Freewave units for this exact purpose.

[Dan Deussen @ Weber Motor]

Brian,

Would you mind sharing the exact model and price of the Freewave units you have used?

Thank you,

[B Lewis @ PE Engine Management]

No problem Dan. The latest model that we have worked with is the DGR-115R. We have also had success with older models of the Freewave transceivers, but I am not sure what models (they are long gone now). Seems to me the price for a DGR is around $1000 per transceiver. I think that you could reduce the cost, however, by going with another package. I think that they all function in pretty much the same way.

[Griff]

We're developing a system using Aerocomm tranceivers. Depending which model you get they have excellent range and you just plug them into the serial. They can work over USB too. There are lots of details at http://www.aerocomm.com/.

[bigtoyota9]

We bought some aerocomm wireless modems a while back i think they were about 1000 bucks a piece. They were bought using money for an electrical engineering senior project which never really worked out. Last year we contacted aerocomm about the tranceivers we had and they said we had the super old ones and gave us the newest model free of charge, just as long as we sent the old ones back. We had some guys looking at getting them implemented but all they suceeded in doin was using them to transmit MP3's in thier apt. Then we had a hard time seeing the value of having telemetry so they are just hanging out in a cabinet in the shop.

I would like to hear what kind of luck you guys have getting yours to work griff.

[Griff]

Do you know which model you guys have right now? We just ordered ours today. It was a development kit that was originally quoted at $1000, but then we got the kit from mouser for $200. The kit includes 2 modules with everything you need to run them. If your interested in selling yours you can email me at jgriffit@uoguelph.ca

[Luis Martinez]

Hello guys.
I want to know if the freewave modules can be bought on line and in which web page.
Tnahks

[Erich Ohlde]

Has anyone used MaxStream Radios? I've got a wireless dev. kit at home that i haven't been able to test with (cold weather and a broken car). The company is claiming 1500ft with a monopole and 7 mile (LOS) with a dipole antenna. I/O Data rates at 57,600 bps. interfaces with RS-232/422/485. I'm planning on doing a bunch of testing with this during driver training and testing/tuning of our '05 car. I'll let u guys know how well it works

[Luis Martinez]

Hello guys.

Have some of you already used some radio modules? I want to know if the modules are exactly the way that says in the datasheets. I have some doubts if they have a real good performance because nobody has used the modules in the car.

Thanks a lot.

[Greg H]

Jayhawk,
Us folks down I-70 just purchased a development kit from MaxStream and our DAG is just starting to work with it, but we can update you later. Got a web special: $299 instead of $499.

[Erich Ohlde]

Greg,
Awesome. What data system are you using? I believe we are going to start autoxing our 04 car on march 1. I will post my results with the radios. But please keep me informed on your progress with the radios.