How to connect and configure GPS + Compass?

metrox · August 15, 2016, 9:00am

Hi there, I have some problems to get my GPS with compass running:

I know I order the GPS Module for CC3D but I want install it on my APM Mini 3.1, is there differents hardware or protocols? I guess it’s just the wiring that changes? No ?

I have re-wired it cause it comes with four wires only, SD and SC were missing, GND, 5V, SD, SC, RX, TX, are all connected to my APM MINI 3.1.

The GPS module has the led flashing blue at 1Hz, according to my research that means a GPS fix.

Now I don’t know if I have to set up something in APM Planner (2.0.20 Mac) because the Flight data info window shows no GPS data, compass calibration fail.

Thanks in advance for your help.

billb · August 15, 2016, 11:22pm

The NEO7M is compatible with ArduPilot. There isn’t anything you need to specify for the GPS.

As for the compass part, you may need to adjust the compass orientation depending on which orientation it is on the board.

see http://copter.ardupilot.org & http://ardupilot.org/copter/docs/common-compass-setup-advanced.html

metrox · August 16, 2016, 7:35am

Thanks for your answer Bill, I double checked my wiring and found that RX and TX were reversed so I just connected RX to TX and TX to RX, and I have the GPS data showing in the AP2 now.

Now I still try to figure why the compass is missing in AP2, I suspect that I fail to cut the jumper on the APM Mini, it comes with solder on each contact. It’s so small that I cannot see if the contact is well open, I am scared to damage the board if I cut too deep. EDIT: I checked this and it seems to be OK.

Is there a way to see the jumper state in the software? Is there something like a parameter to choose from internal and external compass?

I believe that the built-in APM Mini compass has never worked. I’ve read somewhere that on those Chinese boards the built-in compass doesn’t work.

I am going to buy a new tip for my soldering iron and desoldering wick to clean up the jumper and a magnifying glass to see the jumper state; I am currently using the iPhone zoom but the iPhone is quite bad for the macro.

Any advises welcomes as I am struggling for several hours with this issue. On the other hand, I’ve just received my MINIM OSD Micro, and it took only 10 minutes to get it work and to have the telemetry on the goggles, so I am not totally desperate yet. Getting GPS and OSD working is not bad for today

Tim_D · August 16, 2016, 9:43pm

If that link to your module is correct and the image on that page is correct then that module does not have a compass. How many wires come out of the GPS module? Is it 4 or 6?

Also what value is “COMPASS_DEV_ID” in your parameter list?

metrox · August 17, 2016, 8:48am

I have soldered SD and SC wires because it comes with only four wires, there is a compass on the board; I can see it. I don’t have the parameter “COMPASS_DEV_ID” in my parameter list.

billb · August 18, 2016, 3:50am

There is no way for the APM2.x board to know if the compass is external or not. It just won’t report values if not working.