SOL-ONE: ROBOTIC ANGLE-POISE LAMP

SOL-ONE is a robotic angle-poise desk lamp built to always point the light where your hands are working across a table or workbench.

A consistent inconvenience I face every day working at my admittedly large desk is that my angle poise lamp always needs adjusting as I move around during the making process. An example of a common workflow I'd encounter is sketching something into a booklet - an exercise that needs focused light in the right direction so my hand doesn't cast a shadow onto where I draw.

Then moving to check on my 3D print as it progresses - requiring the lamp to be directed through the glass. Then moving up to find a specific tool or part box on the shelf rack above my desk - again requiring some intentional lamp poising. Of course none of this can qualify as anything more than a minor inconvenience, but why settle?

To make this possible, inside are 5 servo motors mounted at each joint, along with a micro camera mounted inside the lightbox itself. The camera takes in a live feed of the workbench. This is fed into a barebones machine vision model to recognise hand shapes. From here, the controller program sends instructions to the motors inside each joint, for the lamp as a whole to move with the sole purpose of keeping these hands in the centre of the camera.

Since the camera is mounted onto the lightbox, it ensures the LED's are always illuminating the hands and whatever they are working on.

For the joint actuators I chose the Feetech STS3215 — a popular smart servo — and paired it with a Seeed Studio XIAO ESP32-S3. The ESP32 handles the control logic and, crucially, brings WiFi to the table, opening the door to smart-home connectivity down the line.

The light itself is produced by two 30 cm runs of COB LED strip with adjustable colour temperature and a Colour Rendering Index (CRI) of greater than 90. CRI is a measure of how faithfully a light source reveals the true colour of an object compared to natural daylight. For anyone looking to buy or build their own lights, I'd strongly recommend keeping an eye on the CRI rating — it genuinely makes a difference, and I personally find a high-CRI source far easier on the eyes over a long session.

The strips run at 24 V, so a buck converter steps the 24 V supply brick down to the 3.3 V the ESP32 needs. Because the strip is addressable — it carries a separate white line and yellow line for colour mixing — two LED drivers are used. Each takes a 24 V line, a ground line and a PWM line, then outputs the driven PWM into a GPIO pin on the ESP alongside its ground.

This makes for an interesting circuit-layout challenge, and I'd recommend committing to a custom PCB early — hand-soldering a five-wire junction is not a fun afternoon.