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Motors & Control
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Topic starter
2019-06-22 4:55 pm
Hi,
I’m new to this forum and new to Arduino. I’m working on a project to control my window blinds in the tilt axis only. I have the prototype blind working with an Arduino Uno and a DXW90 micro servo. The code seems to work pretty well, (I may want to add 10 more degrees of travel). I am trying to control 12 blinds and I’m hoping to use a PCA9685 16 channel controller with all of the servos powered by an independent power supply but also tied on the neg leg to the Arduino. I have a unique situation with having (4) extra 22 ga home run wires at each window so I plan to have only the servos at each window with the Arduino and power supply in a utility room. Would you know if the PWM leg or the power/ground legs would have a significant amount of line loss? My longest run is 55’. My current prototype is controlling the blinds with a photo sensor using a 3 second time delay to account for lightning but I’d be interested in ideas to control it by a z wave switch. I’m also not sure how I would control the 12 servos with the PCA9685. Please offer any suggestions you may have.
Thanks,
Ray
2019-06-23 1:38 am
Hi Ray,
The first check I would make is the resistance of the wire you are going to use. To get a rough estimate, measure the wire resistance with a multimeter and do this calculation: Voltage drop = I (current source of GPIO PWM line) x resistance. You could have issues with ambient noise along the run as well. Long unshielded DC runs are always fun.
Scott
Topic starter
2019-06-23 6:21 am
Thanks for the reply Scott I’m traveling today but will check their resistance when I return home These wires were originally used for the original alarm system that was using a glass break sensor at each window, hopefully there is some noise protection.