Thank you for the reminder of checking micro-sd storage. I replaced with a 32GB card and flashed with "Erle-Brain2-PXFmini-RaspberryPiZero-frambuesa-12-10-2016.img.gz". However, I got a new problem now. I can arm and disarm through both APM Planner and turnigy-i6. However, the hexacopter doesn't even takeoff now.
I did ESC calibrations before I the operation. I used 6 carbon fiber propeller for the operation (ordered from erlerobotics, with purple and blue head) instead of standard yellow propellers (with black and silver head). Both the standard or carbon fiber ones are of the same size (9450). I remembered that only 35% thrust will be enough to takeoff with standard propellers. After I increase the thrust with CH3 stick to even 100%, the copter doesn't takeoff , while spinning in CCW direction (I didn't use the landing legs but attached a layer of airbag, about 3cm thick, under the body frame as a simple protection. The airbag surface is a little slippy and that's why the copter is able to spin on the ground). Even if I move yaw stick to right most 100%, the copter still spin CCW and there are no obvious roll or pitch trend during the operation. I double checked that the propellers and servos were in the right order (CW for arm1,3,6 and CCW for 2,4,5). Then I removed the propellers and wrote down the following servo_ raw PWM values in the order servo1-6:
Disrarmed 1000 1000 1000 1000 1000 1000
Armed 1070 1070 1070 1070 1070 1070
25% thrust 1381 1326 1330 1377 1365 1343
50% thrust 1628 1500 1497 1630 1577 1556
75% thrust 1765 1655 1667 1754 1733 1690
So far I guess it could be either an ESC module damage or servo damage problems.
Then I changed the servos in this way: servo1 to arm3; servo3 to arm6; servo6 to arm1; servo2 to arm4; servo4 to arm5; servo5 to arm2. Then I did the ESC calibration. After the calibration, I tried to takeoff, and it still spin on ground in CCW, no roll or pitch trend, and didn't takeoff when thrust is up to 100%. I just want to know if there is something wrong?
BTW, can it be the propeller problem? Do stand and carbon fiber propeller has the same lift and drag ratio aerodynamically? I measured the length, width and thickness and find the following conclusion: they have the same length and width and the thickness of carbon fiber propeller is
distinctly smaller than the standard propeller.