Hi, I am trying to set-up communication to the coin change-giver from my Linux box using the Python code. The change giver uses MDB (Multi Drop Bus) serial protocol to communicate with the master. MDB protocol is the 9bit serial protocol: (TX, RX lines only) 9600bps, 9bits, No Parity, 1 Start, 1 Stop.
I would like to control the UART "parity bit" to try to simulate 9bit communication. Using Pyserial it is possible to set the parity bit as ODD, EVEN or NONE. I have found in the following link (paragraph 21.3) http://howtos.linux.com/howtos/Serial-HOWTO-21.shtml#ss21.1 that UART hardware supports two "rarely used" parity settings as well: mark parity and space parity (these setings are also known as "sticky parity") A "mark" is a 1-bit (or logic 1) and a "space" is a 0-bit (or logic 0). For mark parity, the parity bit is always a one-bit. For space parity it's always a zero-bit. Does anybody here knows some "tricks" how to set up the mark and space parity on the UART (using pyserial???), so I can simulate 9bit communication? (I know it sounds silly, but I would like to try to re-configure the UART parity before each byte transmission). Any comment will be appreciated. Petr Jakes -- http://mail.python.org/mailman/listinfo/python-list
