I’m using one of my cores to automate the blinds on my house and after removing the pull string tilting mechanism and making an adapter to attach an HS-311 servo to the tilt rod (this picture may help understand what i just said http://i.imgur.com/HItOMlr.jpg).
I was able to successfully open and close the blinds via curl. The only issue i have ran into is the fact that after setting the angle on the blinds even though they move, the servo ends up with strain which keeps it engaged so not only does it make the whining noise it will also drain the battery faster than the solar cell can recharge it, the only way i have found to get around this is to set the degrees + or - 10 after the intial movement depending on which way the blinds moved, although this sometimes works to disengage the servo it doesn’t always work.
I tried using servo.detach() but this only kills the PWM signal which locks the servo in the current angle position but doesn’t disengage it. I have thought about running the power for the servo through a relay that is also controlled by the core however this is not ideal and it’ll also bring up the cost for all the blinds in my house.
Does anyone know if the core has the ability to disable one of the ground pins or maybe disengage a servo via PWM?