GPS PMB 648 Only Updates Every 50 Meters

Andy9707

Hello,

I need some help with the PMB-648. I am using it with the Propeller chip. Initially it would only update if I walk a distance of approximately 50 meters. Then I read a thread here that discusses how to change the mode so that it will update at short distances. I attempted to follow the instructions and now all I get are zeros. i believe I may have set it to binary or raw mode? Now I am not sure how to fix it. I have tried a number of things to no avail and am not sure how to fix it?

Can anybody provide me with the code to reset the chip to NMEA output and also set it to "walking Mode" (The term that was used)? I am new to both the propeller and the GPS module so your help is greatly appreciated.

Thanks in advance.

PJAllen

I needed to configure a PMB-688. I used a SiRF app that I got when I bought another GPS a few years ago. It worked with the '688, because it's SiRF, too. Maybe everything is SiRF, I don't claim to be a GPS expert.

Your '648 has RS232 I/O on its pins 5 (data out) and 6 (data in). So, if you connect GPS pin 5 to 9pin_serial pin 2, GPS pin 6 to 9pin_serial pin 3, and GPS pin 4 to 9pin_serial pin 5 [gnd], then you should be able to use the SiRF app (see attachment.) It should get you back to NMEA-ville.

Nobody from tech support seems to be reading posts these days, too busy pampering brats and coddling losers.

Ken Gracey

PJAllen, you're a critical member of the team: often funny, cynical, and retrospective. But rarely critical of others even though you got a brief smirk out of me on this post (I'd fall into the category of a "code looser needing coddling"). Bring back the former Counsel of Despair for us.

I'll ask the tech support crew (we have four of them now!) to actively participate in the forums. And in this case we clearly need to produce or update our documentation so we don't make our customers sleuth around for the right answers.

I've got just the person to answer this question: Daniel. He experienced the same problem at UPEW. Today is his first day at Parallax, too.

- Ken

PJ Allen wrote: »

I needed to configure a PMB-688. I used a SiRF app that I got when I bought another GPS a few years ago. It worked with the '688, because it's SiRF, too. Maybe everything is SiRF, I don't claim to be a GPS expert.

Your '648 has RS232 I/O on its pins 5 (data out) and 6 (data in). So, if you connect GPS pin 5 to 9pin_serial pin 2, GPS pin 6 to 9pin_serial pin 3, and GPS pin 4 to 9pin_serial pin 5 [gnd], then you should be able to use the SiRF app (see attachment.) It should get you back to NMEA-ville.

Nobody from tech support seems to be reading posts these days, too busy pampering brats and coddling losers.

sylvie369

I did, a few weeks ago, accidentally set a 688 to binary mode. Using the SirF (or is it SiRF?) manual and a terminal program I was able to issue a command to set it back to NMEA mode, to my great relief. It can be done.

I did need to figure out the proper checksum, which was quite a trick given I didn't know anything else about what I was doing. I don't know that I could repeat the feat. If the SirF (SiRF) software does it without requiring you to know what you're doing, you'll definitely want to go that way. :smilewinkgrin: