Automatic Blinds

I have finally got round to implementing a project I have wanted to do for a few years: Automate my log cabin blinds.

The blinds are (well used to be ) opened and closed by twisting a perspex pole, which is attached to the mechanism at the top. Servo motors were therefore the obvious choice to automate this function. However, most are only designed to turn up to 360 degrees whereas the pole required 6 full turns to open or close fully. Fortunately, you can get sail winch servo motors which are designed (as the name says) to raise and lower model yacht sails.

The hardest part of the project was (as I expected), physically attaching the motors to the blind mechanism. After lots of experiments, I managed it as the first picture shows.

The servos were then wired to the Raspberry Pi using a 16 channel servo controller which communicates via the I2C serial bus.

Waveshare 16-Channel 12-Bit PWM Servo Driver for Raspberry Pi ...

Then it was down to writing the python code and adding it to my current control system. I followed several articles but this was one of the best.

And finally the blinds in action: