External compass not working

Hello,
I have a problem with an additional compass Bestar BN -880 .
My Navio+ could not see him at i2c . In the settings I have my external compass enable. At the same settings in Pixhawk this compass works properly .
The raspberry 2B system and APM binary downloaded from the links on the DOCS.
Has anyone had a similar problem ?

Best Regards
Marcin Brzozowski

@brzoza

Hello Marcin!

Could you please attach the output of sudo i2cdetect -y 1? Thus we can understand if the compass gets detected by Raspberry.

I thought it one needs to edit the source files to use an external compass? Because the MPU9250s compass is already seen as external?

@schuermannsebastian

As far as APM concerned the AK8963 is internal, I suppose. During the APM 3.2 development series the support for several compass backends save been added. So I think one might just plug an external magnetometer and play. But I haven’t done much testing on the issue, because at the time I tried that, there had been no support for external magnetometers’ logging in GCSs.

I’ ll keep you posted as soon as I get an external HMC5883 to play with. It’ll be in a couple of days. I’m not completely sure if one needs to alter the source code, though.

@schuermannsebastian @brzoza

I just hooked up an external HMC5883 and everything’s turned out great. It just works.

I can see both compasses updating in the APMPlanner Graph tool. They do update and do that separately.

George, what is you set frequency for i2c /etc/modprobe.d/i2c.conf? Default is 1 MHz but in manual from HMC5883L posted that works up to 400 kHz

@brzoza

I use the same Raspbian image as you. That’s why I2C is configured at 1Mhz as well. How long are the wires you use? You could try to shorten them a bit.

I checked out the short wires (10 cm) - is not working. Target wire is 80 cm.