open and close a pet door. it will raise straight up, and close down.
i will create a door on sliders, a motor to hoist/lower and sensor to know full open, full close positions.
I have relays on system to a 12v source already.
My thoughts -
simply turn on the motor via relay on until fully open sensor tripped (like a do(lift) - while(senor not tripped)).
then, when wanted, use an h-bridge, or another relay (on reverse volts) to close using same concept.
would this work, or do I need a motor controller or other approach?
What size motor? You said 12V, but how much current? If you already have 2 DPDT 12VDC relays, I would use that with transistors to switch the coil current. What kind of relays do you have?
It would be ideal to control the motors using an external motor driver. Unless you have a motor shield that you can use, the Arduino will not be able to control any voltage at all; especially motors which need a constant 12v supply.
Thx guys. I haven’t picked the motor yet. Relays say 15A rated.
This will be a small door. Like most certainly less than 5lbs. I’d probably start with a smaller 12v dc motor that has worm gear reducer -so low rpm, high torque (and hopefully low current draw).
I’d consider the motor “dumb” in that exact speed or distance traveled not so important