Review: Light Paintbrush for Circuit Playground
I love when a DIY project gives you something that feels almost like a magic trick. The TV-B-Gone project is one such project, but so is this LED paintbrush project published by John Park on Adafruit.
John Park has an embarrassing number of great projects, but I ordered up the parts for this one specifically because I’ve been looking for an approachable project with a fun payoff to use for a beginner electronics workshop I’m teaching in April. I love the idea of students walking away with a unique gadget to show off, rather than just a blinking LED.
Ultimately, I’ve gone with another project for my workshop because for better or worse — this project is just too damn easy to put together. It’s great, don’t get me wrong. But I can’t fill up a 45 minute workshop with a project that realistically takes just 10 minutes to wire up and code.
That said, I fully encourage anyone to give this project a try. The total of materials is around $30 plus shipping, which isn’t cheap but every element of this project and be reused and reprogrammed into other projects. That was another part of its appeal — no soldering. Technically, John’s build involved some soldered connections between the three potentiometer (a.k.a. the knob) terminals and the 3 alligator clip wires, but I found it easy to accomplish without soldering provided that you use a potentiometer with big, graspable leads for the alligator clips to hook onto.
Aside from the short alligator clips and the 10k potentiometer, you also need to pick up a battery pack (3xAAA) with a JST connection, and an Adafruit Circuit Playground board. The Circuit Playground is the real centerpiece of this project, since it not only holds the code (Arduino code) but also includes a ring of color-changing LEDs and an accelerometer for detecting movement.
How it Works
What makes the project work is that the code listens to the accelerometer for info on the board’s position (left, right, up, down, etc.) and translates that data into values for the color changing LEDs (“when left, turn blue”). The potentiometer is just there to adjust the brightness of the LEDs. You could technically build the project without it, but it’s nice to have.
Painting with Light
To put the light paintbrush to use, you’ll need a either a nice camera with a manual shutter mode (set to long exposure) or a smartphone loaded with a long exposure photo app. I took these photos with my nice Sony DSLR. But on John Park’s recommendation, I also downloaded and tried the free LongExpo app for my iPhone, which worked great considering the price but took a little time to adjust the settings. If you end up giving this project a try in a classroom setting, LongExpo is a good solution you can recommend to students or use yourself in class with a little practice.
You can see John’s full instructions for this project (and video) on Adafruit.