So this is a capture from a comm line for an automotive ultrasonic sensor. The sensor runs off of one wire, so I am assuming it must be asynchronous serial. I am trying to capture its ping and listen commands, so I can use some others for my own purposes. I have been able to bit bang it and get it to ping, but figuring out the actually serial protocol would be ever so helpful for when I actually want to extract some useful info from the echo. The logic analyzer doesn't recognize it right off, and I simply don't know enough to figure it out. Even a proprietary protocol should be able to be deciphered right?
Not much of a sample but the shortest pulse seems to be about 0.333 mS. If that pulse represents one bit time it would be about 3000 bits per second. That's not very close to the common async speeds 2400 and 4800. Perhaps it uses one of the automotive standards like CAN.
Thanks guys. the 3000 bps works great. only a couple framing errors in a 20 sec capture. I'll have to do some quick reading on how to figure out baud rate to avoid such confusion in the future. While the sample I posted fits 16 bits nicely. most of the other patterns are about half that length. Unfortunately I can't find a way to compress the data in my capture to a postable size.
