I'm interfacing a PMB-648 gps module, which has the SiRFstarIII chipset, with a PIC18f4520. I've managed to get rid of the messages that I didn't need, and now, it sends over a GLL message at 1HZ.
The problem is, is that it doesn't update the Latitude and Longitude. Where it is when it gets its satellite fix is what I get no matter where I take it. I can watch the clock increment the seconds, but the location will not change unless I cycle power on the module.
I can manage this with the PIC , but it seems kind of slow having to wait for it to aquire a new fix every time.
Is there a $PSRFcommand to get an update without having to turn it off and back on?
You may have to put the GPS module in Walk mode. I had to do this with a PMB 248, and based on some other forum threads, I think you have to do the same with the 648. This forum thread describes the solution.
I’m writing my code in c, using the c18 compiler from Microchip. To begin, I used hyperterminal to observe the $GP sentences that the module exports. I’ll try the $CCGPQ. What’s it supposed to do?
is what is used to tell the gps module to send you something and what it is that you want. In the example I showed, it will reply with GLL sentences until you tell it otherwise. Is that not the sentence you use to tell it to start sending GLL data to you?
Reading through that pdf showed the various i/o for devices that follow that protocol. On page 3 it mentions how one would go about getting specific data from a given device.
