Has anyone got the PIC to work with MDB protocol (vending)?

[mikebar]

Mikebar, I dont use the Hserout or Hserin commands in any of my code. I truly do not know how MELabs handles the parity bit in its implementation of there code. The uart register TXD9 is for setting the bit manually. It is upto the programmer to set this bit and to interpret the RXD9 bit after reception. I have done this in the past, using it for the same purpose as you have discribed. I would suggest maybe looking at Darrels DT_INTS routines and use the hardware uart and place it into the 8 bit w/parity mode then set the TXD9 bit to your liking.. Same thing on the receive side of things.. I would however try the implementation you described in your last post and see if you can set the TXD9 bit just before the Hserout command and then see if it sticks...

Dave Purola,
N8NTA

Ok, thank you Dave.
I'll go on studying the MDB documentation (as said more than 300 pages). As soon I can I'll buy some MDB client device (like a bill acceptor) and wire-up some circuit to test it.
If, in the meanwhile, you have some idea to test it will be really appreciated.

[Dave]

mikebar, What I would do if I were you is: wire up 2 pic's connected the same way you discribe in post #10 and write the code to do the exact same thing. One of the pic's would be the master and one pic would act as the bill exceptor. Then see if it works....

Dave Purola,
N8NTA