This DIY Device Can Test Up to 16 Servos at the Same Time

Hobby-style servos like those from Hitec and Futaba allow makers to create a wide array of animatronic projects at a relatively low cost and effort. However, testing them isn’t as simple as just plugging one in to power; a PWM source is required. If you’re anything like Will Cogley, this usually means a quick bit of breadboarding and serial programming to get things moving. It's a simple enough task of course, but if you want to experiment with a lot of servos at once, or rather not reinvent the wheel over and over, a better solution is needed.

With a servo-intensive mystery project on the horizon, Cogley decided to finally make such a device: a 3D-printed servo tester with an Arduino Uno at its heart. The unit features inputs for 16 servos at a time via an Adafruit PCA9685 16-Channel Servo Driver and four potentiometers to adjust the PWM outputs. Two buttons switch the inputs among the four sets of four servos for control, while feedback is provided by a 1.8” TFT display that shows all servo positions at once.

The housing is cleverly designed to fold together, enabling the connections to be made before manipulating everything into a more constricted space. The Uno’s USB port is accessible when the enclosure is folded up, allowing changes to be easily made as needed. It’s a clever and useful design, and it’ll be exciting to see the “secret” project that it’s intended to facilitate!