Why use digtal 3 for output?

[vfbl]

Hi there,

Before extra motors and ESCs arrive to make my multi, I need 6 channels for adapting multiwii for single rotor CP use, i.e. 3 channels for the 3 axes plus 1 for throttle, CCPM pitch and gyro gain (AUX options)

I find it strange that we use digital 3 on pro mini as a servo output for BI and TRI, such that we are left with 2, 4, 5, 6 and 7 on port D served by PCINT. I am one channel short. I won't touch Tx and Rx, but I would like to have 3 back.

I am now using 3 as an input and putting my servo outputs on A0, A1, 10 and 11 instead. It seems to work.

Were there any reasons why we have been using pin 3 as output?

Regards.

[noobee]

i believe it is because digital 3 has a hardware pwm engine to generate output for the servo/esc.

[vfbl]

The servos are not driven by HW PWM on multiwii. We manually turn the servo pins on or off at timeouts. The motors are using the HW though.

Anyway I only have 1 motor to drive on a "monowii". At first I don't bother driving the motor via the pro mini, but if we want to calibrate or trim the ACC on throttle max, it would make the motor going nuts unless we disarm it via pro mini. I'll put that on 9 then.

Thanks.