Set the 232C data bits to 7 bits

janet24 · Joined: 16 Apr 2019 Posts: 1

I want to receive data from the other party in 232C communication.
However, the other party transmits data bits in 7 bits.
If you set 7 bit as below, you can not receive.
If the other party is 8 bit, it will be received normally.
Someone please help me.

temtronic · Posted: Tue Apr 16, 2019 5:15 am

Quick reply...

I'd use ( 8-N-1) for the RS232 options
#use rs232(baud=2400, xmit=PIN_D6, rcv=PIN_D7, bits=8, parity=N, stop=1)

and simply mask (remove) the MSB as that bit would be the parity bit from the other device.

This should work providing the HW UART is being used.
You don't say if you have to confirm that parity is correct, that'd be more code and I don't know if USE RS232() will do that calculation for you.

I didn't see any info in the datasheet that the HW UART can be configured for parity so I suspect that USE RS232 is designed to do this.
Others will know....just have to wait a bit....

ALSO you MUST add 'ERRORS' to the options otherwise the UART will 'lockup' due to overflow of incoming data.

Jay