pcmhacking.net

Aside from ECUs, another hobby of mine is radios. Ive been wondering and thinking that it might not be too hard to create a bin that outputs mode 1 data frames automatically, one after another, and then feeds some hardware that can perhaps convert the data to standard 9600 serial and interleave some GPS co-ordinate data and send it off via a UHF radio. This could then be received on the side of the track and provide realtime telementary including track location/speed etc etc. From that braking points could be compared to lap times etc etc.

Nice idea. In terms of the ECU code there is a message schedule table that is used for the BCM anti-theft stuff, it can be modified and adapted to automatically schedule a mode 1 frame to be sent automatically fairly easily.

Sounds like an interesting idea. From what I remember you can feed standard low-baud (up to 10kbyte or so) serial data into the 433mhz UHF modules that places such Jaycar and Oatley Electronics sell. If this is correct then it should be fairly simple to use the standard ALDL > serial transistor circuit to feed into the transmitter. This will only get you uni-directional comms, but you could always use 2 pairs of transmitters/receivers since they are fairly cheap. Apparrently 1-4km range is possible too. So I think the ALDL side of it will be pretty easy to organise, but it still leaves the GPS side of things to be sorted...

Linky to modules

There is a lot of amature radio stuff like the tinytrack modules http://www.byonics.com/tinytrak/ that do gps over radio. Im not sure the resolution though, can GPSs output locations faster than 1 per second? Straight up you could run 2 radios, but a more advanced project could interleave the data. I like the idea of the 430mhz transponders, they would be cheap and easy for people who dont have or dont want larger radios.

I dont think bi-directional comms would be necessary, as you could hack something together on the receiving side to let a reply through to whatever scanning app when it sees an outbound mode1 request.

I was thinking a full data modem would be the go, but if the 430mhz module will just work feeding 8192 baud data straight in then thats a nice option.

great idea .man those transmitters are amasingly small and not much to them that would fit in my ecu with all the goodies i allready have in it im wondering wether it may interfer with the ecu operation though if mounted inside the ecu.but its small enough to mount anywhere in the car really.if we get any more good stuff to add to the ecu i may need to upgrade to the 1227165 case as its bigger and i can fit more in there LOL

Most cheap GPS transmitters operate at around 5-10Hz, some go up to 20Hz and still aren't too expensive. The TinyTrak looks cool but for telemetry I think we'd be better off transmitting in serial if we can and skip the analogue conversion to conventional radio ala TinyTrak and just transmit the NMEA serial data from the GPS unmodified. I think a serial multiplexer would be the go, combine the 2 signals before the radio eg ALDL+GPS > 433Mhz TX -====- 433Mhz RX > Laptop. From my brief google search it seems the most common way serial multiplexers work is to use a cheap PIC to add a prefix to each serial port and then retransmit the data and let the receiving PC sort out which port is which via the ID, which would mean using a virtual comms port, right up your alley I think The biggest issue will be making the 2 data streams easy to interpret and keeping them time synced.

Yeah, I was thinking 1 aldl packet + 1 gps packet at a time, and the data speed would throttle the pc to whatever speed was obtainable. But, bi-directional real time aldl, how cool would that be? Could have or be the techo on the sidelines tuning the car while its racing on the track!

how serious are you hahaha

hey ant youre gonna need a clone if you keep this up one to drive so you can tune LOL

Hey delco - I drive you tune (bloody shifters on the wrong side)

as the US Navy said to our Govt. "I can neither confirm or deny" i put up this post

not allowed to log at a race meet - nothing about the three pre-season practices mentioned tho

and with wireless internet all here cold potentially monitor and give feedback in realtime

f*** me the mind boggles