wireless data transmission

[tsf14]

Hei everyone, new to the forum here.

i'm still new to fsae, so i'm a bit jittery about certain aspects about the race and the car, but i'm learning.

many teams have implemented real-time wireless data transmissions over the years, so i was wondering- what kind of technology is most popular to the teams, that meets both budget and requirements? there are teams that uses xbee, serial wireless, etc but what are the basic pros and cons making one preferable to the other?

is there any rules/regulation i should be aware of?



thanks a lot.

[B Lewis @ PE Engine Management]

Depends on what you are trying to do. We use wireless Ethernet with our ECUs for a low cost solution for FSAE teams and other racing apps. Depending on your antenna, it works pretty good for short ranges.

[wweissin]

Brian is spot on with using a wireless router being a good solution for FSAE. How ever I feel I must point out that Telem is outlawed in most professional racing series. And for FSAE at the track it is my opinion that you would be better served by focusing attention to other more important aspects of you electronics package. However, with that said it can have its merits when practicing by keeping a driver from damaging a car if he is not watch certain aspects of the car.

[tsf14]

wireless router seems to be alright, but the range is a bit too low for practical real-time data transmission. is anyone familiar with xbee? technically it has the potetial to serve the purpose, but i personally only heard of this a few days ago.

(yes, this is basically a novelty idea, but our electrical package didn't evolve much from last year's design, so i was thinking about adding a bit of a flare here!)

[B Lewis @ PE Engine Management]

What range are you interested in? With an industrial router and good antenna you can get pretty good range.

[BMEP]

Originally posted by B Lewis @ PE Engine Management:
What range are you interested in? With an industrial router and good antenna you can get pretty good range.
What do you consider good range?

[Some Guy]

Xbee has potential I think. It can basically function as a wireless serial cable from what I understand. That means with a bit of level shifting it should be able to work with most systems as they wont even know the Xbee is there. The thing you have to watch out for as far as I can tell is conflicts with your baud rates.

There are a gazillion different configurations Xbees out there though, some already are set up for rs232 other need you to do level shifting and supply 5v or 3.3v (one of those two).

I find xbee quite appealing because it is very inexpensive and from those who I have talked it is quite easy to set up.

[Wesley]

Just get a high gain 802.11 antenna on a stick and point it at the car. Perfect newbie job.

[Jon Burford]

We are using the X-BEE pro units with a serial interface to transmit data collected by our race tech DL1. the DL1 is also picking up ECU data via CAN. it all works rather nicely with full speed serial and a good range. all in all very pleased with the X-BEE

[Nicky]

We have some background working with the Zigbee Pro. It works at 2.1GHz with a data rate of 255kbps(RS232). We flicked the college router antennas(9dBi gain and expensive). Streams data over 800m flawlessly(earlier barely managed over 80m with the wire antenna. We're yet to interface it with the CAN on our car.


Originally posted by Jon Burford:
We are using the X-BEE pro units with a serial interface to transmit data collected by our race tech DL1. the DL1 is also picking up ECU data via CAN.

We don't have the moolah for a DL1. We're trying to get data off the M800 via CAN as the telemetry option costs over $700(AU). Have you used any CAN controllers or recommend any to use.


Regards,
Nicky

[Jon Burford]

the project was meant to be completed by a EE but sadly it was not. We ended up buying the DL1 CAN interface.
The whole package know works well. we use a DTA ecu but the interface for a M800 is also available. sadly without the DL1 it's useless.
what about transmitting the computer interface for the ecu? the DTA has a serial port for connecting to the computer which we could use if we didnt have a DL1?

[Nicky]

Did think about that: getting the CAN/USB directly hooked to the computer and let the software used by the motec employ the data. The problem is with the 1Mbps data rates that the M800 CAN uses. It can be slowed to 500kbps, but thats still a lot than what can be transmitted over a x-bee. (Any suggestions would be appreciated)

Thought of making an ethernet connection, but then comes the task of packeting/un-packeting the CAN/USB information on a TCP/IP. And with CAN/USB working at 12MHz, it's quite impossible to packet that data, unless you get an expensive controller to start with.

Running out of options. And hence currently looking at getting the data off the CAN and transmit it via rs232.

[Jay Lawrence]

Doubt it's worth anything, but i would tend to agree with Alex. Basically, to me, wireless telemetry is something that you have a go at after the rest of the car is 'perfect.' Until then, you make sure the car is safe to drive, you send it on a lap or two, check it, make adjustments as necessary, then send it out some more. Our series doesn't require us to drive for long enough to necessitate a race engineer watching oil and water for the duration. That's what warning lights are for.