OpenMarine

I would like to know if Pypilot can control a stepper motor?

I would like to connect a motor directly to the head of the self-steering windvane.  The head will rotate only about 30 degrees each direction so I am thinking a brushed motor might not be able to increment in that small amount. Or am I wrong about that?

Would adding a pwm control accomplish the same thing?  How about setting the gains way down instead?  With the paddle removed from the vane there would be very little resistance.

The best way to do this with pypilot currently would be to gear down a brushed motor sufficiently. My actuator moves my main rudder by 30 degrees per second, so if you geared it similarly so that 1-2 seconds moves the full range it should work as well. The motor required to do this could be very small. There are linear actuators available which move very slowly 10-20mm/s and you could probably rig this up to work.

Stepper motors generally consume more power, unless they are closed-loop. They are great for accuracy but in an autopilot there are constantly errors that are being compensated for, so absolute accuracy is not required, at least not for a boat that can steer well using a wind vane.