Sorry for the reposted message. I had posted this on the BeagleBone group, but this is an issue with the BeagleBone Black.
I am having some problems trying to use a GPS receiver with the BeagleBone black. I connected a PMB-648/688 module to one of the BBB UART ports. I can see the NMEA messages coming from the GPS receiver, but I never get a valid fix. I doesn’t report any satellites in view (GPGSV messages). Not even if I leave it on my rooftop for a couple hours.
Initially I thought it might be a problem with the GPS receivers, so I tested them on my laptop. Every one of the receivers I have worked fine, taking a less than a minute to get a fix from my window.
The next thing i thought was that there might be some power supply noise messing with the GPS receiver, so I tried powering the receiver by itself (connecting the grounds of my receiver supply and the BBB). Surprisingly, this worked. More surprisingly, it stopped working If I moved the BBB close to the GPS receiver.
This lead me to suspect that the BBB might be causing some RF interference on the GPS frequency band. My next test was to have the GPS receiver and the BBB powered independently. This confirmed my suspicion. If I powered the GPS receiver, waited until it got a valid GPS fix, powered the BBB, and placed the BBB close to the GPS receiver, the I would get the same result as before. No GPS fix, no satellites in view. Since the two devices are being powered with two independent power sources, then the BBB must be causing some RF interference. I do not have a RF spectrum analyzer to confirm this, but I do not see any other reason.I tested this with three different BBB and 6 different PMB-648/688. I always got the same result.
I tried the same GPS receiver on a Raspberry Pi and It works fine, so that is what I am going to work with for the moment. But I really like the BBB, and would love to use it for my application. Is there anything I could do to fix this?
I’m sure other people have used GPS receivers with the BBB. Can anyone recommend a GPS receiver that works with the BBB? I’m looking for a receiver that’s approximately the same size (3cm*3cm) and price ($35-$40) as the PMB-648/688. I’m getting the Adafruit Ultimate GPS soon, so I’ll report about that.