Raspberry Pi GPIO control<\/h2>\n\n\n\n
I happened to have an old Raspberry Pi lying around, and I built up a circuit that had an three separate LEDs: Red, Green, and Blue. Each was connected to a separate GPIO pin and I used keyboard input to turn on and off the LEDs.<\/p>\n\n\n\n
Once I completed that, I grabbed and RGB LED and wired that into the same GPIO pins, and was able to directly control that through the same method as the individual LEDs.<\/p>\n\n\n\n
Here’s the circuit with all the LEDs in place:<\/p>\n\n\n\n I also had a Circuit Playground Express<\/a> lying around and it has an infrared receiver. I used a remote control from a commercial LED lightbulb and some code to process the signal and change the onboard RGB LEDs based on button presses from the remote.<\/p>\n\n\n\n I then stumbled on the AdaFruit Rotary Trinkey<\/a> and built some code to change the onboard LED. I wanted to have the knob control the each color of the RGB LED individually.<\/p>\n\n\n\n I’ve been a fan of the Micro:bit ecosystem, so I wanted to use it to control LEDs. I have some experience controlling NeoPixels from a Micro:bit so I wired up a strand something like this one<\/a> to the Micro:bit. I have asked Claude to help me build a QLC+ connector in another recent project<\/a> so I figured I’d try to use it again for this one. It built me the Micro:bit firmware and a bridge between QLC+ and the Micro:bit. Ultimately, I was able to use the sliders in QLC+ to change the individual colors in each LED. <\/p>\n\n\n\n Unfortunately, there were a couple things I couldn’t overcome. First is that I couldn’t get the protocol timing quite right, so I couldn’t send QLC+ cues, or any more data than a single slider at a time. (I did have better luck using the Circuit Playground Express, which seemed to have better serial behavior.) Also, the Micro:bit didn’t provide quite enough voltage, so the LEDs misbehaved a little bit. Overall, I was excited to build a good proof of concept.<\/p>\n\n\n\n In order to supply better power to the LEDs, and because I bought a servo arm<\/a> that also needed more power, I bought a Micro:bit Crickit<\/a>. I was going to buy the Circuit Playground Express Crickit<\/a>, but it was out of stock so I figured I’d give the Micro:bit a shot with better electrical power. The LEDs behaved much better with the Crickit, but the serial was still flakey so I couldn’t send lots of data from QLC+, so I may ultimately have to move back to the Circuit Playground Express for the serial performance, but this was a good upgrade.<\/p>\n\n\n\n![\"\"](\"https:\/\/engineeringharmony.com\/wp-content\/uploads\/2026\/06\/1000084741-1024x925.jpg\")
<\/figure>\n\n\n\nAdafruit Circuit Playground Express infrared control<\/h2>\n\n\n\n
Adafruit Rotary Trinkey<\/a><\/h2>\n\n\n\n
Micro:bit control<\/h2>\n\n\n\n
Servo control with Micro:bit Crickit<\/h2>\n\n\n\n
![\"\"](\"https:\/\/engineeringharmony.com\/wp-content\/uploads\/2026\/06\/1000084742-1024x768.jpg\")
<\/figure>\n","protected":false},"excerpt":{"rendered":"