Tom Hammond's Two-in-One "Pixel Tester" Makes Testing Lighting Setups a Cinch

Maker Tom Hammond has designed a two-in-one tool that aims to assist with troubleshooting LED light setups: a combination bench-top power supply and "Pixel Tester."

"[This is] a new invention to help with Christmas lights troubleshooting and other electronics hobbies," Hammond explains of the device. "This combines a power supply, digital buck/boost converter with display, and a two-port pixel controller. You can use your phone to interact with the lights (no app required, it's a Wi-Fi access point). It defaults to a red-green-blue-white pattern at power-up. The silver button in the lower-right allows two user-defined actions in WLED without needing to involve your phone. And it's an xLights receiver, too."

Hammond's tool is built around a low-cost adjustable DC voltage regulator designed to deliver 120W at up to 6A or up to 36V, whichever hits the limit first. This is linked to a 6A 12V DC power supply, though the voltage regulator will work on supplies as low as 6V, and an Espressif ESP32-based digital lighting controller running the WLED firmware. Everything is off-the-shelf, with Hammond's contribution coming in how everything is connected together in a custom-made housing.

"It can test two strings of 800 lights (Ray Wu and xConnect supported)," Hammond says of the finished device. "It will test any pixel voltage (5, 12, 24V). You can dial-down the voltage to see how the lights work with low voltage (a common problem). It also serves as a bench power supply for any voltage up to 36V and 6A. You feed it one power source, it will adapt to any voltage that you need. You can plug it into the wall (AC input) or strap-on a power bank via USB-C to make it portable! The case is 3D printed (of course). I've been wanting something like this for years."

The project is detailed in full on Instructables, though anyone looking to follow in Hammond's footsteps should observe the usual precautions about working with mains power supplies.