How do I send the break for the LIN nodes to listen for the sync byte using pyserial and a raspberry pi

1
votes

I am trying to use the RPi as a LIN Master to communicate with a number of slave nodes on the LIN bus. I can send the correct bytes, starting with the sync byte of 0x55, and then the node ID, the message data and the checksum.

In order for the nodes to listen, I need to send zeros for at least 13 bit-times prior to the sync byte. In pyserial, the port is set to eightbits, so, of course, I can only send 8 zeros when I need at least 13. Any ideas for solving this?

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raspberry-pisyncbreakpyserial
After thinking about it for a bit, you are probably going to get a better answer on raspberrypi.stackexchange.com or failing that electronics.stackexchange.com – Peter M
Thanks for the suggestion. I will give the pi site a try. – user3276635

1 Answers

1
votes

Changing the baud rate to a lower value before sending 0x00, and after sending the byte change it to the default baud rate (fore sending 0x55 and data). So the time when the LIN-Bus is 'low' is long enough to activate the slaves. This worked fine for me.