Hey all, I'm newish to arduino and would like advice on my first project.
I'd like to build a little device to open and close my window if the temperature in my room goes above a certain threshold. My thinking is that I'll have a thermistor leading into one of the analog in pins and if the value drops below a certain value I'd activate the motors.
My questions is what is the best way to handle the motors. I'm going to be using a screw jack powered by motors to open and close the window, so I may need two motors to push and pull the window. I think I can probably add an attachment to pull the window back closed as well though.
Either way, how would you recommend controlling multiple motors or a single motor to do this task. Do I need a motor shield (I'm a bit unsure on if a motor shield is necessary, or when it would be necessary for a project) or can I just power the motors straight from the arduino.
Those will likely be fairly hefty motors.
Using a DPDT relay to switch AC to the motors will likely be best, with 2nd relay to connect the mains to the motors.
The relays can controlled by Arduino outputs switching a transistor to enable coil current. I'll post a pic in moment.
Thanks for the help, but I'm afraid I don't know what the nc and no paths stand for, and a quick google search yields nothing. Would anyone mind helping me out.
I was trying to show how the current flowed one direction (NC path, say to open the window) vs the NO path (to close the window) in a relay-based H-bridge for a motor.
DPDT (double pole, double throw) relay will have 2 sets of contact pins - each set has a Common pin that connects to the Normally Closed (NC) contact when the relay is not energized, and to the Normally Open (NO) pin when the relay is energized.
example:
SPDT (single pole, double throw) has one set.
example:
SPST (single pole, single throw) only has 2 contacts, Common and Normally Open, that are connected when the relay is energized.
example:
If you need a relatively powerful motor on the cheap, an old Harbor Freight rechargable drill motor works wonders. It can be powered with an old PC power supply and you'll most likely be able to control it's direction with an H-bridge or motor driver.
