2023-05-27, 06:10 PM
So much for my theory. If Seatalk data idles at less than 12V its surprising that you get any data at all with the alternative wiring.
Caveat, measuring with a multimeter is problematic as it will average voltage levels if there's active traffic. I recently came across this site, which also says that data idles at 12V: http://www.thomasknauf.de/seatalk.htm
Two alternative explanations:
I think I will have to get my hands on a Seatalk1 system to debug this issue.
Caveat, measuring with a multimeter is problematic as it will average voltage levels if there's active traffic. I recently came across this site, which also says that data idles at 12V: http://www.thomasknauf.de/seatalk.htm
Two alternative explanations:
- The signal on the Raspberry Pi side of the optocoupler isn't "digital" enough to be properly decoded
- The Pi drops bits as it can't read the GPIO consistently enough to decode at 4800 baud - though not clear why that wouldn't be an issue with the original wiring
I think I will have to get my hands on a Seatalk1 system to debug this issue.