I am no longer offering support for the decoder or transponder threads, but all of the documentation is now available on DropBox:

https://www.dropbox.com/s/tbl2ostbkv...21_17.zip?dl=0

Thank you very much I send you a private message.
You stopped the project? I am French and I could not read the whole subject but it looked very interesting.
Thank you

Hello to all working on that great project,
the last days I was reading a lot interesting stuff here and decided to try to build the system on my own, following your documentation. Howard, could I please get the latest documentation too?

Thank you and best regards from Germany,
Robert

Send me your email address via a private message.

The documentation is in a large zip file, 16.5M, so make sure your email can handle it!

Hi Howard, thanks for your design, I'm working on my design and I'm facing 'wrong' sequences when I swipe (manually) the transponder across the loop. Fixed transponder causes about 100% good readings. Mostly the error seems to be a missing zero bit (no reverse). To give an idea 1600 of 2000 packets are correct (considering the full length of the frame). Also the errors are located in two 'burst' of wrong packets (maybe wire crossing?). Do you have any number to check if I have to debug further or the values seem 'right'. At the moment I'm spitting out every packet I receive, without any check for repetition. The wrong packets do not repeat in sequence.

Missed bits are unavoidable, and are especially prone to occur during low reception levels (at the edges of the loop, for example). That's the reason to look for three identical data receptions in a row before accepting the transponder as valid. Even then, there will be a few spurious receptions, where three identical but incorrect receptions will occur in a row. At that point it is up to the lap counting software on the PC to determine if the transponder is valid (in other words, one of the participants in the race). If not, then the lap counting software should ignore them.

For what I understand in the thread this repetition is valid for oldest transponders, whereas new RC4 transponders always change numbers every time. Also, three in a row is ok from a single transponder in the loop, but does this work with multiple transponders? Anyway I'll investigate further if I have something to optimize in my design in order to minimize this bit misalignment... OR implement CRC check of the packet. By the way...this is my prototype, on top right is your loop amplifier... the rest is in the board, with a USB serial port. It's pretty impressive that I'm reading something since this is my first project with this hardware... Next is a camera shot for the amp waveform (old technology, I know....)

All current documentation for the decoder and transponders is now on DropBox. Use this link:

https://www.dropbox.com/s/tbl2ostbkv...21_17.zip?dl=0

Please forgive this delayed response, as I am no longer guaranteed to be monitoring this thread or providing support.

The decoder is not compatible with the newest MyLaps transponders, as indicated in the specifications.

Once the decoder sees three repetitions in a row, the transponder is "verified", and will be counted for any other receptions, even those that are not repeated. The three-in-a-row verification is done during the race warm-up, where cars usually pass individually under the loop. Any that don't (as indicated by the PC software) should be requested to drive under the loop before the race is started.

If you can modify your code to recognize the meaning of the transponder data and do a CRC check, that would be a huge improvement. (At least one other reader has accomplished this.) Please share the code on this thread when completed!

Dear Howard

I'm trying to build my own transponders and decoders, but I'm new in this thinks. I saw you built your own transponders.


I'm an electronic enthusiast and I find this trying to find how to make a transmitter with a microcontroller unit to send the beakon with the transponder ID to a raspberry. But when I found you could send in AMB decoders protocol I found this much more nice than do a new incompatible system.

Do they work with AMB TRANX2 Decoder? I also buy one recently to our motocycle association because we are in a kart race track and some race drivers have already theyr one AMB Tranx260 transponders

It is possible for me to create my own transponders?

I saw you use a ATMEL IC microcontroller a cristal and some mode chips to buils the transponder, but than we have the problem of the program to load in IC, I never did that

Can you help-me?

machadofisher

Whenyou have problems with Decoder not detecting a transponder passage, it might be that the Signal/Noice ratio just is not enough. In the original AMB/Mylaps system the difference should be at least 60, (signal 120 and noice 20 is quite good, but if the noice goes up to 80, the transponder just will not be detected).

Hi, I'm new in this forum. I come here looking for a consistent lap timer for my club. I also see IR systems but I think this solution is better.
I've read howard will not continue to offer support and I want to know if there is somebody had boards and pics to start with it.

I have electronics skills and pcb fab but I read somewhere pcbs are 4 layers that will be impossible to make at home. I also see some guy that have smd version that looks awesome but not source for it.

Do you guys can help me to guide me where to start? 44 pages of forum it is a heavy start . Some blog, wiki, etc?
Info from dropbox is great but I think a lot of info is assumed from forum posts and I'm a bit lost.

Thanks

It is all here. I did it the same way as you want to. You will need to get a pcb fab company like dirtypcbs.com to make the main board for you the amp board is easy either home etch or bug build, all the files you need are on dropbox, the bom is good for amp, decoder and you should be all set. The only difference now is you need to program the chips yourself as Howard is no longer providing this service. Again all the files are available, you will need to get access to a programmer.

Hi, thanks for the reply. I have a pickit3 programmer for pics And usbasp, tinyAsp and arduinos for atmels.
Is there something I have to keep in mind before I begin? Any advice?
Thank you very much