Stephen Heinz Turns Cheap Solar Marine Buoys Into Solar-Powered Meshtastic Nodes

Engineering manager and maker Stephen Heinz is building robust, weatherproof, deploy-anywhere solar-powered nodes for the Meshtastic LoRa mesh network — by repurposing cheap marine buoys.

"This [guide] shows how to repurpose an inexpensive solar anchor buoy light to build an extremely durable and waterproof solar powered Meshtastic node," Heinz explains of the project. "My original prototype has been living its best life 80 feet up in a tall tree since August 2024. So far it has proven to be extremely reliable with range only limited by line of sight!"

The buoys in question are sold as anchor- or net-marking devices for watercraft: solar panels on the sides keep an internal 18650 lithium-ion battery topped up, and an array of LEDs blink up through a lens when triggered — alerting other watercraft as to where your anchor or net is set. As you'd expect, they're designed to be weather- and water-proof to an extreme — and it's those very features that attracted Heinz to reusing them as nodes on the community-driven Meshtastic network.

Heinz' conversion takes one of the off-the-shelf light beacons and extracts the electronics bar the battery and solar panels, leaving room for a RAKwireless WisBlock Mini Meshtastic Starter Kit with compatible solar connector cable. A pigtail provides a means of attaching a range-boosting high-gain antenna outside the main body of the buoy — with the connection point waterproof using a resin that cures under ultraviolet light.

"Before I designed a 3D printed bracket for this, I found it frustrating that the antenna connectors would frequently pop off while screwing the cap onto the tube," Heinz notes of the assembly process. "One time a board got itself wedged in at a weird angle and I accidentally bent and broke the board while unscrewing the cap. Not fun. My bracket features a secure screw mount for the bottom edge of a RAK19003 board, a pillar to stabilize the USB port, Bluetooth antenna holder, and a safety tab to prevent the LoRa IPX connector from disconnecting."

The project is documented mostly-fully on Instructables, but Heinz admits it's missing one important step: "In a followup Instructable I will demonstrate how to add a BMS [Battery Management System] protection circuit to the 18650 battery that comes with this solar buoy," he writes. "The RAK board will function properly and charge the battery without a BMS circuit. However, a BMS is important to prevent overcharging or undercharging, which can damage the battery and create a fire hazard."