Hi Juan, Interesting problem. I'm using a Ublox UP501 GPS module with my BBB and haven't experienced anything like that. I can also run the module right next to the black without issues. However, I have a large cape that covers the BBB and my power source is a battery with a heavily decoupled supply feeding the BBB and the GPS. The GPS module also has its own regulator and filtering. Here's a picture<http://andicelabs.com/wp-content/uploads/2013/11/IMG_0837s.jpg>of my setup if you're interested.
Pretty sure that the UP501 uses the same MediaTek chipset as the module that Adafruit carries. It'll be interesting to hear what your results are with it. -Ron On Sunday, November 17, 2013 5:59:52 PM UTC-6, [email protected] wrote: > > Hello everyone, > > Sorry for the repost. i had posted this on the BeaglBone group, but this > is a BBB issue. > > 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. > > Thanks! > > --Juan Camilo > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
