This color-changing lamp emulates a “touch” sensor with a microphone

YouTuber “Peterbiglab” wanted an input for his DIY color-changing lamp, but didn’t want to use buttons or even have it detect claps, so he decided to make it respond to touch. 

Instead of using a capacitive sensor or force-sensitive resistor, he placed a microphone inside his lamp to hear inputs. An op-amp was also included to pull the voltage up to a level that can be read by its Arduino Nano.

With code implemented to keep it from picking up on music and other sounds, the device can now be controlled with finger taps: two to switch colors, three to turn on/off , or even four to enter Hue mode. It’s an ingeniously-simple sensing method, which works well here, and could be applied to a variety of other projects.