This is a discussion to focus the feedback and support of ardupilot on the PixRacer board from AUAV.co.
We believe that all teething problems encountered are now resolved and so we recommend people load Copter-3.3.4 which is available for all multicopters through the Mission Planner's (and other GCS's) Install Firmware screens. Note that because regular Pixhawks are still on Copter-3.3.3 the install icon may show Copter-3.3.3 but rest assured, Copter-3.3.4 will be installed (you can check the version by looking at the very top of the Mission Planner).
Also make sure your ATC_ACCEL_P_MAX and ATC_ACCEL_R_MAX are set quite high, start at 100000. It's also very important on these small quads to set THR_MID and THR_MIN, in particular lower THR_MIN as low as you can without stalling the props on low throttle. If you don't lower THR_MIN then the flight controller doesn't have enough of a range of throttle to stabilize properly at low throttle (hover).
Yes THR_MIN is set a bit high , i will decrease and try
But THR_MID is set at 300, I have understand that this parameter is use to althold , loiter mode ?
try to increase ATC_ACCEL_P/R to 100000.
P=0.01 is too low, so it won't react quickly enough and fly like a boat. The easiest way to do this is to assign rateKp to chan6 which is usually a dial on your tx, and set the range to something like 0.02 to 0.06. Then start with the dial in the middle (=0.04) and you can change it while you're flying until you get something that's responsive. Once you get used to it, it's quite straight forward and works across most sizes of craft.
I think traditionally arducopter isn't used much on smaller quads, so the settings are more difficult to setup at first. I'm sure with the likes of pixracer and fpv, this will change quickly.
thanks, i will try your method next days.
But I have identified a strange reaction of throttle management :
- my quad is armed and my props turn and when i put my throttle to zero , I notice that prop turning speed is not linear, it's like "2 speed management" , At zero throttle : a specific speed and after 1 second an other specific speed (thr_min) ... ?
What is the setting for the first speed before thr_min? It seems that my PID works with with speed manegement...unlinear with 2 speed seetings and make ma quad unflyable?
Yes that's what you can get if you have thr settings not quite right, also if you haven't calibrated ESCs possibly. Try lowering thr_min, also mot_spin_armed (which has to be lower than thr_min). If you lower these settings, it should then jump less when you raise the throttle.
I often save my parameters to a file. Then I can use the "Compare" feature in Mission Planner to see what's different. If I want to change a couple I uncheck all of them and then check the ones I want to update. Most of the time I'm checking PID values between copters or after an Auto Tune to see how it changed.
I'm still having a couple old problems, with the current beta... I thought they were fixed, but maybe not..
I can't calibrate ESC's in oneshot mode. They never enter calibration mode... they just activate as normal when rebooting into calibration mode. The flight controller does go into calibration mode, but the ESC's don't seem to care.
And, the 3rd compass does not work. As soon as I disable it, I can arm. If it is enabled, I get "compass not calibrated" even though it is.
I just 'landed' in a lake, completely submerged. Took it out, dried it off, and she still flys. Even all my FPV/Camera equipment is OK.
It's actually more impressive than that, because I tried powering it on when it was about 1/2 dry.. and it worked for a few min and died. I was sure it was lost. But after a complete dry, it's ok!!