Hope someone can help me out here.
I am trialing an ALFAT SDR/F40 board with a PJRC Teensy 3.2 micro controller and a GPS.
Both the SDR and ALFAT SDR are connected via separate UART ports.
Both boards work well in isolation of each other.
The GPS works perfectly with NMEA sentences coming out at the correct 9600 baud rate into either Serial1, 2, or 3 (depending on how their wired and read from within code). I’ve tried all 3 with the same effect.
The ALFAT SDR board also works perfectly on either of the serial ports.
Now this is where is gets interesting.
If the ALFAT SDR board is powered, then the GPS module cannot see any satellites and loses its fix. That is, if the GPS module is running prior to powering up the ALFAT SDR and receiving satellites, as soon as the ALFAT SDR board is powered on, whether or not it is connected to any serial ports on the Teensy, the GPS receiver loses all signals.
The GPS module still continues to transmit its 9600 baud NMEA sentences, but cannot receive any satellite signals. I can see the sentences work perfectly receiving satellites and a fix, and as soon as the ALFAT SDR is powered up the sentences lose their GPS data. All NMEA sentences from the GPS unit are being transmitted and received fine.
I’ve even tried the ALFAT SDR board on different power supplies with the same effect. As soon as the ALFAT SDR board is powered up - it kills the GPS’s ability to receive satellite signals.
All power supplies have been grounded - thereby eliminating possible ground issues.
I have tried 3 different GPS modules, 2 of the same NEO UBLOX 6 and 7 type and even a SkyMaster GPS module. The ALFAT SDR module has the same effect on all three.
So, all I can assume now is that the ALFAT SDR board is emitting so much that it is interfering with any type of GPS module to receive signals.
Has anyone had this issue before?
If so, how did you resolve the issue?
Does GHI know about this issue?
If so, is there any workaround?
I really like your product for its plug and play features, but unfortunately, its not workable around GPS receivers in its current format.
Any help is greatly appreciated.