Monochron: auto-brightness with hardware mod using light-dep
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Monochron: auto-brightness with hardware mod using light-dep

by af3556 on Sun Aug 03, 2014 8:27 am

The Monochron sits proudly in my son's bedroom, alas it can be too bright of a night.

We added a light dependant resistor (LDR) poking out the back of the Monochron, and with a little supporting software we have auto-brightness control. The display backlight now smoothly ramps from dimmest to brightest according to the ambient light levels.

Hardware

Circuit:
Image

Implementation:
Image
Image
Image

Note that we wanted to have the LDR on the back of the unit for aesthetic reasons (knowing that making a hole in the acrylic case with hand tools was likely to turn out a little ugly), but doing that definitely made the re-assembly very difficult. In hindsight, I'd probably have used flying leads from the ldr to the PCB, so as to be able to tuck the LDR over the existing ISP hole.

Software

Building on Toine Ceulemans' amazing Emuchron:
https://github.com/bdlow/Emuchron/tree/autobrightness
af3556
 
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Re: Monochron: auto-brightness with hardware mod using light

by adafruit_support_bill on Sun Aug 03, 2014 8:45 am

Nice work. Thanks for posting!
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adafruit_support_bill
 
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