Adding a second GPS to Navio and GPS issues


From pretty much the first day of having the Navio2 I’ve always had a somewhat unreliable GPS. It often takes a very long time to find any satellites, it doesn’t work at all if the battery starts getting low and it often looses fix. I am running it with a wifi setup which is probably affecting the signal which is why I have an MCX extender cable on order so I can position the GPS in the tailplane. I have also shielded my UBEC and RPI Camera. However as an added measure, I have an older GPS off the Ardrucopter 2.8 I rerouted the wires so I could plug the SDA and SCL into the I2C port and the 5v, GND, Tx, Rx into the UART port. The GPS is the U-blox NEO-6M-0-001.

I have activated the second GPS in the startup commands with “-E /dev/ttyAMA0” and changed the appropriate eg. GPS-TYPE2, GPS-AUTO-SWITCH and the Serial4, options in mission planner. When I turn the RPI, the light on the GPS glows however when I connect gpsstatus2 stays at 0 also when I connect to the RPI via U-Center I can’t see to find a second GPS. Is there any way I could check on the RPI if it is recognizing the GPS that is plugged into the UART port? Or does anyone have any suggestions that could help me with my GPS issues?

I am running the latest image and the latest version of Adruplane.

first off, you shoulnt be having all those issues with the Navio2 GPS, works rock solid for me every time, I would try to figure out why all those issues first, maybe a bad GPS sensor on the board?
I do have dual GPS on a non-navio Pixhawk setup and works remarkably well but only on AC3.5rc5, maybe try a newer beta release for Arduplane? also common mistake when hookin up serial is that you have the TX/RX connected to each other where they need to be reversed (TX to RX and RX to TX), if this is happening it would explain why it powers up but no data, triple check this, it happens to everyone, self included.
Also what do you mean serial4? the NAvio only has one serial port so I think on AP you would be configuring Serial1 instead with 5 as GPS protocol, or am I missing something?

last thing, the ublox 6M is not really all that good, a much nicer option for $25 USD is a the M8N…

Serial 3 UART B is for GPS1 (Int)
Serial 4 UART E is for GPS2 (Ext)

If connected to Navio UART plug, [quote=“sam_naissen, post:1, topic:6057”]
-E /dev/ttyAMA0

is OK.

In Parameter list, serial speed should be set to 38400 if GPS serial speed is set to 38400 (it could be at default 9600). Check it with u-center.


but you are still bound to the limitation of a single UART port on the Navio correct? I dont understand even the logical assignment with a single physical port, how do you tell Ardupilot that whats plugged into the serial port is Serial 4 GPS, how about if I had a 3DR telemetry radio instead?? why would it be serial4 and not serial1? thank you

Have a look at

I have 3DR Radio on USB and GPS2 on Navio UART

-C /dev/ttyUSB0 -E /dev/ttyAMA0


Thanks @iriol the RX and TX were connected wrong, silly mistake. I shielded all the cables near the GPS including the GPS cable however what I found out was happening was that the EMF being produced by the WiFi access point was messing with the signals on the Navio itself. Just moving the WiFi access point double the distance away as what it originally was, and sorted my GPS out quicksmart.