2017-06-19, 05:50 PM
In my fork the most important change to the mpu9255 is that it uses the internal fifo for mag readings. It's not yet back-ported to the mpu9250, but that should be easy.
Before it would use the fifo for accel and gyro, but read the mag explicitly. This had a rather serious bug that sometimes you got mismatched high and low bytes (different samples) and it had a lot of overhead. It used too much cpu to sample the mag fast enough.
Now, you could simply read the fifo at 10hz, even though the sensors are sampled at 100hz, and it averages the 10 readings giving lower noise of 100hz sample, but updating the kalman filter at 10hz.
I think it would be great to update openplotter. Btw, I tried downloading the image and no seeds on torrent, and also mega keeps timing out on me.
As for pypilot, all the sources are released now github.com/pypilot/pypilot and you could try it. Of course, it runs it's own signalk server which doesn't completely conform to the signalk spec right now, but the differences are probably trivial. The mpu9255 must be read from the realtime process in the autopilot. You can get the data into openplotter or nodered or opencpn or whatever by connecting to the autopilot. It would be unacceptable to add any lag between reading the gyro and commanding the rudder.
Before it would use the fifo for accel and gyro, but read the mag explicitly. This had a rather serious bug that sometimes you got mismatched high and low bytes (different samples) and it had a lot of overhead. It used too much cpu to sample the mag fast enough.
Now, you could simply read the fifo at 10hz, even though the sensors are sampled at 100hz, and it averages the 10 readings giving lower noise of 100hz sample, but updating the kalman filter at 10hz.
I think it would be great to update openplotter. Btw, I tried downloading the image and no seeds on torrent, and also mega keeps timing out on me.
As for pypilot, all the sources are released now github.com/pypilot/pypilot and you could try it. Of course, it runs it's own signalk server which doesn't completely conform to the signalk spec right now, but the differences are probably trivial. The mpu9255 must be read from the realtime process in the autopilot. You can get the data into openplotter or nodered or opencpn or whatever by connecting to the autopilot. It would be unacceptable to add any lag between reading the gyro and commanding the rudder.