Re: J1850 VPW Sniffer
Posted: Fri Jul 17, 2020 12:01 pm
I see this is your first post! Thanks for chiming in. Those are cheap boards, wow! $3. I'd like to write to the ECUs ideally. I really would like some software to make sniffing easier.babbish wrote:I wanted a sniffer as well a few months ago and I already had some Bluepill STM32 boards so I wrote some code to do the VPW -> UART for them, I was planning on writing about it/publishing it but haven't had the time yet.
The best thing about those boards are they are ~$3 USD including the programmer (subsequent boards are cheaper without the programmer) from Aliexpress (https://www.aliexpress.com/item/32649400326.html)
The code definitely isn't very good but it does mostly work, so if anyone wants a copy let me know and I'm happy to send it. Eventually I hope to clean it up and implement writing with correct contention handling as well, which would make this a very cheap very nice tool.
The one caveat is the voltage obviously, these are 3V boards, but for sniffing a simple voltage divider (2 resistors) worked perfectly, obviously writing would be more involved but I'm hoping the PCM is more sensitive to out of spec voltages than it should be.