My project is working, although I'm still tweaking things both in code and electrically.
It's a program for PICAXE 08M2 microcontroller to keep blinds open to allow maximum light up to a setpoint.
Tweaks the blinds open now and then to try to get more light in, unless the light goes above the setpoint, then it
turns them down until the setpoint.
Circuit needs a gearbox motor attached to the swivel device that opens or closes venetian blinds.
Based on original circuit/program by Randy Crowell
http://www.instructables.com/id/Build-A-Motorized-Window-Blinds-Controller-For-Les/
Circuit was modified as follows:
* 1 button attached to pin 3 (with pulldown resistors as specified in picaxe manual) (other button removed)
* Motor switched by another relay instead of directly by darlington array, and on completely separate set of batteries (hope to switch this back to original design)
* 3X 220nf capacitor in series with 120ohm resistor to ground, as low pass filter to reduce noise, these are attached as follows, to 5V rail, to low voltage side of each relay coil
(I had electrical noise problems that kept resetting the PicAXE, presumably because the supply votage dropped momentarily. Moving the motor
to a separate set of batteries, having it switched by the relay,
and adding the low pass filters has solved the problem.)
Designed to keep my office bright, but to close the blinds when the sun shines directly in, because bright sun glares off my computer monitor.
Closing the blinds manually when the sun shines was easy enough, but opening them back up
(and keeping them at the optimum position)
when the sun goes behind a cloud or building, or moves up or down with the time of day in overcast conditions,
required dedication or some automation with a microcontroller.
I wasn't getting up every 15 minutes to tweak the blinds, so I was
sitting in the dark all day if the sun peaked through the clouds at 9AM.
This program could also be used to maintain bright indirect sun on plants (most house plants want lots of light, but not direct sunlight,
which can scorch their leaves and dry them out.)
It's a program for PICAXE 08M2 microcontroller to keep blinds open to allow maximum light up to a setpoint.
Tweaks the blinds open now and then to try to get more light in, unless the light goes above the setpoint, then it
turns them down until the setpoint.
Circuit needs a gearbox motor attached to the swivel device that opens or closes venetian blinds.
Based on original circuit/program by Randy Crowell
http://www.instructables.com/id/Build-A-Motorized-Window-Blinds-Controller-For-Les/
Circuit was modified as follows:
* 1 button attached to pin 3 (with pulldown resistors as specified in picaxe manual) (other button removed)
* Motor switched by another relay instead of directly by darlington array, and on completely separate set of batteries (hope to switch this back to original design)
* 3X 220nf capacitor in series with 120ohm resistor to ground, as low pass filter to reduce noise, these are attached as follows, to 5V rail, to low voltage side of each relay coil
(I had electrical noise problems that kept resetting the PicAXE, presumably because the supply votage dropped momentarily. Moving the motor
to a separate set of batteries, having it switched by the relay,
and adding the low pass filters has solved the problem.)
Designed to keep my office bright, but to close the blinds when the sun shines directly in, because bright sun glares off my computer monitor.
Closing the blinds manually when the sun shines was easy enough, but opening them back up
(and keeping them at the optimum position)
when the sun goes behind a cloud or building, or moves up or down with the time of day in overcast conditions,
required dedication or some automation with a microcontroller.
I wasn't getting up every 15 minutes to tweak the blinds, so I was
sitting in the dark all day if the sun peaked through the clouds at 9AM.
This program could also be used to maintain bright indirect sun on plants (most house plants want lots of light, but not direct sunlight,
which can scorch their leaves and dry them out.)
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