Problem displaying data from GPS module & using 16f877a

[dhouston]

If the GPS works connected to a PC, it means its output is inverted.

You need to modify your

serin2 portc.4,4800,[WAIT("$GPRMC"),STR sms\35]

Reread the manual for SerIn2 - your mode value is incorrect.

[financecatalyst]

If the GPS works connected to a PC, it means its output is inverted.

You need to modify your

serin2 portc.4,4800,[WAIT("$GPRMC"),STR sms\35]

Reread the manual for SerIn2 - your mode value is incorrect.

Thanks for the input but could you help me advising what baud should I use, I am little confused about this. The datasheet of the module does says 4800 is default (Datasheet attached) and manual also has only one option for 4800 baud.

I also want to say that I connected the gps module via MAX232 to the PC.Thanks

[mackrackit]

I always wondered why the manual does not list all of the modes??? Save some paper???
http://www.melabs.com/resources/ser2modes.htm

[financecatalyst]

Thanks for the info. I added the statement:
baud1 con 16572
and changed the following statement:
serin2 portc.4,baud1,[WAIT("$GPRMC"),STR sms\35]

Still no luck. Please help.

[aratti]

serin2 portc.4,baud1,[WAIT("$GPRMC"),STR sms\35]

Which is the value of baud1?

When you use wait string, remember that they are case sensitive "$GPRMC" is different from "$gprmc"

I already suggested you, in another thread, to use a timeout sequence. Your serin2 instruction will wait for the identifier and then it will wait for a string of 35 characters. If your GPRS will send only 34, serin2 will remain there waiting forever.

One turn around is the use of the timeout:

GPRSLoop:
sms[0]=0
serin2 portc.4,baud1,500,GPRSTest,[WAIT("$GPRMC"),STR sms\35]
GPRSTest:
If sms[0]<>0 then goto label ??     ' here you check byte[0] for data presence 
goto GPRSLoop

Al.

[mackrackit]

Thanks for the info. I added the statement:
baud1 con 16572
and changed the following statement:
serin2 portc.4,baud1,[WAIT("$GPRMC"),STR sms\35]

Still no luck. Please help.

If a RS232 chip was needed to talk to a PC then baud1 should be 188.

[financecatalyst]

Thanks guys. It´s up and running now. Love this Forum

[mackrackit]

Thanks guys. It´s up and running now. Love this Forum

In case someone else has a similar problem... What was the fix?