I have send you a PM, thanx :)
Once you can get circuit boards premade, I can order the PIC from Robby and we get a good price for the TPM. I think I will go ahead with this project. This is friggin' cool.
I allready started a screen for my RR skin. This will be a definite usefull addition to the carputer.
I have sent you an email message.
Getting the boards made isnt a big deal at all. There are plenty of places out there where you can have em made for a few bucks a board. or we could get em made overseas with a sexy black silkscreen (or blue, or whatever) for like a dollar a piece. I've done it before.. Its like $300 up front tho for all of em, so probably not ideal.
Anyways, I'm in for a kit, or at least a good price on em if we get enough people that want em.
Ok guys, not to hijack the thread - but there may be light at the end of the tunnel obtaining a receiver board instead of buying the complete setup - a receiver board and sensors should be a lot less expensive than what the suppliers asks for these kits.
That's the datasheet for the receiver chip, an Infineon TDA5200. There is an evalution board available from Infineon for this particular transmitter, and may make it easier to setup this particular application.
@ Robby BMW: Is there a Microchip HCS515 decoder anywhere on the circuitry? Any of the boards?
This will make identifying the coding system easier....and thus helping us out to develope a good solution.
Another chip, which is very comptible with this TDA 5200 Infineon, is the Maxim Max1470 Superheterodyne Receiver - so my guess is any circuit with either of these chips should work with Robby's PIC 18F2550.
I will do some more studying to see what we can do, as I can buy the kit in Australia, but for $600 AUD - which is around USD $550- crazy I'm not.
I think we won't get from any manufacturer builded TPMS kit with USB support for low price because there is not a lot of people who will buy it and this standalone TPMS will buy more people...
P.S. Maybe we will have luck and get any cheap TPMS with USB
Have you looked around, I have found a few other things that are interesting:
With these two products together or separate this could get quite cheap. Chip prices on these start at $6 for volume (obviously we cannot get them as cheap as that)
@ Thwack: Yep, there's quite many different versions available, but I am trying to stick to something that will be fully compatible with Robby BMW's USB interface- otherwise we need to redo everything, which will taake so much longer, time I really don't have.
@ Robby: seems the setup you have uses ASK (amplitude shift-key) modulation....there's also FSK (frequency) and PSK (phase) modulation available.
So, we're getting closer to your setup in terms of what receivers to lookout for....
Any additional input you have, as you have quite thoroughly studied this...
UPDATE on the kit:
I will be receiving my kit today so I'll try to take some pics of it and post, just to verify its the same one as Robby used.
Also, I've etched Robby's circuit onto a board with the famous iron-on/laser-jet/photo paper method and it worked great! Next up: drill the holes, score the board and populate!
Lastly, I have final discount prices on the kit for those of you interested, please contact me for details.