Problem with RS232

spom · Joined: 12 Jul 2007 Posts: 32

Hallo everybody,
I use a PIC 18F2480, the MAX232CPE and Docklight.
When I want to send a string via RS232 I get nonsensical strings. I am sure that the capacitors are right attached.
Where could be the fault?

Thanks for help!

P.s.: below a part of my code:

Ttelmah · Guest

Obvious things:
1) Is your crystal 8MHz?.
2) Is the serial program set to 9600BPS?.
Count how many characters you 'see' when the program starts. If it is close to 15, then suspect a parity or word length problem. If it is much shorter or longer, then look at a baud rate probelm (either from the PIC timings being wrong, or a setting at one end).
3) Unless you are _sure_ the defaults are correct, _specify_ the word length, and parity for your RS232. Both at the PIC, and in the terminal program, and make sure they match.

A couple of 'comments'. Get rid of *=16. This is for _16_ chips. Also get rid of BRG10K. This is for a couple of chips that have faults in the BRG handling. Theseshouldn't cause a problem, but are pointless. Add ERRORS to the serial declaration. At present, if more than one character arrives in the time round the loop (31 byte times), it'll cause the receive UART to hang. Why have a stream name, and use it 'part' of the time, then use STDIO for the rest of the time?. Either use streams, or don't use streams.

Best Wishes