I’m using SW Maps to receive NMEA data from a SparkFun GNSS module over Bluetooth/serial. The issue I’m experiencing is that the data rate shown in SW Maps is highly inconsistent: it drops to 0 B/s for about 1 second, then jumps to 2587 B/s or a similar value, and keeps repeating this cycle.
I’m also using my own NTRIP caster, which is functioning properly and delivers RTCM corrections without issues when tested separately.
I’m also using my own NTRIP caster, which is functioning properly and delivers RTCM corrections without issues when tested independently. To illustrate this, I’ve attached:
Two screenshots of the NTRIP status page in SW Maps, showing the fluctuating data rate.
One screenshot of the caster status report from RTK2go, confirming that the caster is online and receiving a stable RTCM stream.
You mentioned that you are using a Sparkfun GNSS as a Rover.
You are also questioning the NTRIP Caster, which is independent of a Rover.
Are you also operating the Base that’s pushing observations to RTK2Go, with another Sparkfun GNSS ?
Apart from connectivity/bandwidth issues at the Rover, my first thought would be to confirm your Rover is producing the GGA message often enough for sending to the Caster.
You “might” be at a race condition where RTK2Go requires a GGA every 30 seconds (just an example/guess) and the Rover is right at the threshold ?
Like I said… just a guess
The Rover is a SparkFun GNSS module connected to SW Maps via Bluetooth.
The Base is also a SparkFun RTK Reference Station with its own antenna, and I’m sending RTCM corrections using STRSRV (from RTKLIB) to RTK2go.
So the entire setup (base, antenna, caster) is mine.
I see this often and have been ignoring it. I believe the app is showing 0 kb/s periodically because the display is updating multiple times per second, and all the bytes show up in the first 100ms, thus it really is 0 kb/s at least in that slice of time.
If you’re concerned, test with GNSS Master - I believe it shows a rolling count rather than an instantaneous calc.
