I am using Pixhawk as fight controller with APM 3.5.5 Firmware. I am facing a problem with altitude hold mode.
I arm my quad, switch to Altitude hold mode, and then increase the throttle. This is what I observe: motors not rotating till around 1300 value, 1300- 1600 very less rpm of motor (similar to rpm of 1100 value in Stabilize mode), greater than 1600 very high RPM(similar to greater than 1600 of Stabilize mode).
Since the quad did not takeoff even till 1500, I asked my friend to hold the quad at a constant height and then change the altitude by hand to observe the response in motors. The change in rpm was negligible, not sure there was even some change actually.
Stabilize mode is working properly. Stabilizing throttle is around 1250-1300.
I tried PX4Flow sonar as well as Maxbotix sonar for getting the altitude.
Is there any additional parameter to change to tell the quad to switch from distance of barometer to distance of sonar?
Please help. Thanks in advance.