Adding GPS to Vengeance 280

Thanks for all the technical support to date on the Vengeance 280 - got all working fine in the end. On to the next task which is installing a GPS module. Not as ‘plug and play’ as first appears. I’m using the mini UBLOX gps and its all fine until I try and get it connected to the board. Tried multiple configurations.

I can get the GPS working ok through Pins 3 and 4 on the Receiver Input, but then I cant configure the UART2 to accept both RXSerial which it needs for the Spektrum Satellite PPM input and GPS, the save and reboot switches them off. I’ve tried to enable GPS through SoftwareSerial assuming this then works off the 3.3v/GND/TX/RX outputs but the correct configuration crashes the board so guessing there is something amiss there.

Do you have a standard process for a GPS set up I can have?

What receiver are you using with your vengeance? As you should use a CPPM input as that frees up the other UART / soft serial pins for using GPS. GPS will need a dedicated UART port, and cannot be shared with anything else. Can you get the GPS working if you disable the spektrum PPM on that port? However you could try using GPS via softserial?

I’m using the Spektrum AR8000 via the spektrum specific port ie rxserial. It requires uart2 to be enabled for Rx serial as per instructions. I then plug the gps into 5v, gnd, pin 3 and pin 4 but cant get it to function . Maybe gps needs to be enabled on uart 1? How could I use softwareserial?

Dont change any UART1 settings as that is what the USB port uses and changing that could brick your flight controller from connecting to your PC.

You cannot use GPS with a spektrum receiver, you can only use GPS with PPM as the GPS module will use UART 2 exclusively.

Ok great thanks. Yes I figured this out the long way. I am in the process of trying to get CPPM to work through an Orange R615X, but I have a feeling that this isn’t going to work with my Spektrum DX9, so winding back to older technology…

Is there any way to use SoftwareSerial (2) on eg pins 7,8 rather than have them set to Aux channels? This will only work I guess if SoftSerial overrides the use of those pins for the standard PWM input. ie my Spektrum receiver is happy to work on PWM into the standard 10 receiver inputs on the naze32, but do I enable SoftSerial2 to free up 7,8 for gps?

There is unfortunately no way to change the pins for soft serial. I still prefer to use PPM anyway with cleanlfight controllers as it gets the job done and is super easy to setup and connect.

Also let me know about your experiences once you get GPS working on your quad as I have never tried that myself with cleanflight and will be interested to see how it compares to something like arducopter.