PWM Frequencies

AutoQuad will use fast PWM frequencies on the motor ports. For now the frequency is fixed on 400Hz when using the port for motors.  Connecting a standard (analog) servo for use as a gimbal can result in a non working servo because most (analog) servo’s will accept a PWM frequency between 30-100Hz.  Digital servos can go as high as 400Hz, but typically work best in the 300-333Hz range. You can set the desired gimbal servo PWM frequency using the ground control software (QGC), on the Gimbal parameters page.

AQ uses 6 different timers within it’s infrastructure. Within a timer you can only use one frequency. So, for using a lower pwm rate on a port you must use a timer that is not used by a motor.

Port numbers and timers reference

Examples

That raises the question about motor timers. It is possible to occupy all timers for motors, but you could also concentrate them for using as low as 1 timer (for a quad). A table can be made to spot the possibilities;

In this example 3 timers (1, 4 & 2) are used for 4 motors. The gimbals have separate timers.
if you want to use a minimum of timers you could use this example;