Creating motion-controlled cabinet lights with ATtiny85


This strip of white LEDs can be turned on, dimmed, and shut off with a wave of your hand.


In Thomas Snow’s house, the kitchen lights never seem to adequately illuminate his counter space. Beyond that, the Maker always seemed to find that whenever he needed to flick on the light switch, his hands were dirty. Cognizant of both of these things, he decided to devise a simple yet clever solution which consisted of installing a motion-controlled LED strip under his cabinets.

motion_main

As you would imagine, the DIY solution works by simply waving a hand under the cabinet whenever some additional light is required. Snow is able to adjust the brightness by moving his hand up and down within the vertical space between the countertop and cabinet. Think of it as an invisible dimmer switch — or just magic.

This was made possible by employing an ultrasonic range sensor that determines the hand distance between the cabinet and the counter, along with a pyroelectric infrared (PIR) sensor that only activates the ranging when it senses movement around the counter.

“I [didn’t] want to run the sensor all the time because, even though we can’t hear the 40kHz chirp, I imagine the dogs and bird (our pets) can hear it. Additionally, I imagine there is a limited lifetime on the sensor.”

Most importantly, the project is based on an ATtiny85. Snow simply set up an Eclipse environment with the AVR GCC compiler and programmed his own PWM for dimming LEDs)and millisecond counter.

Intrigued by this ‘bright’ idea? Head over to the project’s official Hackaday.io page here.

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