SERIN2 = ok, HSERIN = no!

[flotulopex]

Based on the code in post #12, I removed the WAIT modifier to be able to see what happens on each try (= display anything data that comes into the PIC): HSERIN[STR GPS_D\6].

...and likes a nice pull up resistor...

I removed the MAX232, added a 10k pull-up on PORTC.7 (PIC's RX pin) and changed BAUDCON to % 01001000 (not inverted). It works now!!!


I re-modified the code to: HSERIN [WAIT("$GPGGA,"),STR GPS_D\6]

I now can see "HH:MM:SS" as it should.

Nevertheless, I have my PIC running for more than an hour now and it often hangs (= time is no incrementing every second anymore) and starts overs maybe 10 or 20 seconds later. Seems that the data signal is just at the limit the PIC can "read" it properly. This does not happen in my SERIN2 mode.

With the oscilloscope, I measure 4,7VDC for the highest data signal level on PORTC.7 while the PIC and the GPS module are powered by the PICKit2 and its 4,95VDC from USB.

I think I will choose to stay on the SERIN2 version since it looks more "reliable" and, as already said, needs less components.

[Darrel Taylor]

Nevertheless, I have my PIC running for more than an hour now and it often hangs (= time is no incrementing every second anymore) and starts overs maybe 10 or 20 seconds later.

That sounds more like a USART buffer overflow.
If it isn't cleared ... it will hang.

Try adding ...

DEFINE HSER_CLROERR 1 ' clear overflow automatically