I have a Pixfalcon on a quad copter and was having a lot of trouble getting Arducopter to work, so I’m posting here to provide some help for other people starting out. There’s very little info out there on the Pixfalcon and what works and what doesn’t, I couldn’t tell if I was making mistakes or if only particular versions of Arducopter worked with the Pixfalcon.
Some of this info I’ve posted over on the PX4 forums, but more of a PX4 focus.
I had 3 problems:
1. Could install Arducopter firmware, could calibrate everything except power module/battery voltage. I figured I could set it to ignore the voltage and still work for testing purposes.
2. Could sometimes arm, but motors would be operating randomly, one or two spinning instead of four, sometimes they’d start going to high RPM for no apparent reason. ESCs had already been calibrated and working with PX4. Takeoff was impossible/
3. Flight modes, channel 5, ORX T6 transmitter - need I say more?
Symptoms had me thinking that late versions of Arducopter wouldn’t work with the Pixfalcon. There were reports around of people using AC 3.3.3 and earlier with the Pixfalcon, but I couldn’t seem to download the earlier version to try it. I wasn’t up to building it from source yet. PX4 firmware would just install and work, indicating there was nothing wrong with the Pixfalcon.
1. After installing the latest AC firmware and calibrating, I found that selecting a power board style of “Other” (or whatever suits your setup) I had to reboot the Pixfalcon for it to be possible to then calibrate the voltage in Advanced. Prior to the reboot there was no battery voltage reading. The difference being with PX4 the readings are immediately available and calbration works - this made me think Arducopter was not working properly.
2. For arming and motors to run as expected, I had to recalibrate ESCs, even though they had previously been calibrated manually and via QGC/PX4. and were working OK with PX4.
3. We’re using a Orange RX T6 (Tsix) transmitter and Orange RX R615 receiver. There’s no issues with the receiver. The TX only has a two position flight mode switch on Channel 5.
I was able to set up the ORX T6 to suit flight modes in Arducopter firmware by mixing channel 5 and 6 and output to channel 5 - Arducopter will ONLY use channel 5 for flight modes. With the two switches in combination Arducopter would pick up 5 modes using this method, might get 6 modes with a bit more fiddling.
I’ll see if I can post somewhere else with the details of that channel 5 and 6 mixing.
So really, all traps for new users, not actual faults with arducopter or the Pixfalcon. I’m now on AC 3.5.2 and basic flight testing is OK. We’re yet to get into more advanced flying and tuning.
I can’t work out how to get Autotuning completed by just changing flightmodes, since there’s no separate autotune switch I can use on the TX.
I’ve also changed the firmware parameter to turn off the internal buzzer for flight mode changes, so as not to interfere with accelerometers. I cant say the vibration was an issue, but figured it cant hurt to disable the buzzer anyway.
Since I’ve got a Linux laptop, I’ve found it best/easiest to use QGroundControl for firmware installs, config and calibration. I use APM2 for missions (Auto mode) since it handles the Spline waypoints and advanced features better than QGC. Also I noticed in QGC you cant select “Simple” next to the flight modes, so APM2 is good for that.