Problem with parallax GPS module

bbnqond

Dear all,

I am currently doing a project on GPS, which i have mentioned before in the forum. Yet, I met a problem and i would like to seek help here.

I have connected the GPS module to the BS2PX module. I·run the demo source but shocked to discovered that my module seems out of order. It kept showing the message "Error: No response from GPS Receiver Module". It's true that no satelites should be found as i am working in the lab, yet i can't even get the hardware information of the module. I wonder if i·made any mistakes, I have tri-checked the wiring and confirm that there isn't any problems. Do i have to expose the module to clear sky in order to get the hardware information?

Regards,
bbnqond

Mike Green

The demo is probably not written for the BS2px. The Baud constants for the SEROUT / SERIN statements are different from other Stamps. Some demo programs have conditional compilation for the various Stamp models, but were written before the BS2px was released and haven't been updated. Read the BS2px supplement (Brief): www.parallax.com/Portals/0/Downloads/docs/prod/stamps/BASICStamp2px.pdf (from the webstore product page link).

bbnqond

Mike Green,

Thanks for your quick reply.

So, what can I do? Do i have to edit the baud rate of the code to 19200? But the GPS module's baud rate is 4800.

Regards,
bbnqond

sylvie369

bbnqond said...
Mike Green,

Thanks for your quick reply.

So, what can I do? Do i have to edit the baud rate of the code to 19200? But the GPS module's baud rate is 4800.

Regards,
bbnqond

Read the section of the Basic Stamp Manual on page 397, where the SERIN command is explained. The demo program includes the line

T4800 CON 188

which is used (indirectly) to set the incoming baud rate to 4800. As you can see in the Manual, 188 is the code for the BS2, 4800, 8 bit, no parity, true. The corresponding code for the BS2PX is 813 (lower on the same page).