This Motorized Grow Light Automatically Maximizes Photon Efficiency

If you want to grow a healthy plant indoors in a reasonable amount of time, you’ll want grow lights. But most of the photons — and therefore tasty plant energy — from those lights scatters around the area, rather than reaching the leaves. To maximize efficiency, Bubs built this motorized system that keeps the grow lights focused on the plant.

The goal was to keep an array of LED grow spot lights pointed directly at the top of the plant as it grows, focusing the light to optimize photon absorption. Those lights are red and blue, because plants are green and that color would be wasted as reflection.

Bubs chose to achieve his goal through two methods. The first is with optical lenses that narrow the throw of the LEDs, keeping the light from spilling out to the surrounding area. He even created a simulator in Python to see how the light would land on the plant with different LED positions.

The second method was motorized actuation of the entire LED array. That assembly hangs from a kind of winch that can raise the LEDs up and down, which means it can go up over time as the plant grows taller.

To put that all together, Bubs used PCBWay’s SLM (selective laser melting) aluminum 3D printing service to fabricate LED mounts that double as heat sinks. The LED drivers operate under the control of ESP32 dev boards, so Bubs can control them remotely, along with the winch system. It can be set to change lighting intensity on a schedule and lift over time. But there are also spare GPIO pins, so Bubs can add sensors to make the whole system “smart” in the future.

We don’t know yet if it works well, but it sure looks cool.