The project's hardware, including the ESP32 camera module, stuffed into the GoPro-intended waterproof shell. The camera portion of the ESP32 module sticks out exactly where the GoPro's camera would be. To the left, a hacked ESP32-CAM module is shown.

Hackaday Prize 2022: Solar-Harvesting ESP32 Camera Is Waterproof, Repeatable

[alberto nunez] shows off his sleek build of a solar-harvesting ESP32 camera – waterproof, somewhat energy-efficient, and able to be built by more-or-less anyone. For that, he’s chosen fairly jellybean components – an ESP32-CAM module with a matching protoboard, a small solar cell, a LiFePO4 battery, and a waterproofed GoPro shell that all of these parts neatly fit into.

A BQ25504 energy harvesting chip is used to ensure the ‘solar’ part of the project can meaningfully contribute to the project’s power budget, with energy otherwise mainly provided by the LiFePo4 battery. Since this battery’s nominal voltage is 3.2 V, it can be wired straight to ESP32’s power input and there’s no need for a regulator – thus, that one got mercilessly desoldered. [alberto] has also modded the board using a FET to gate power to the ESP32-CAM module’s camera, with all of these hacks bringing the board’s deep sleep current from 2.8 mA to 0.8 mA. Not great for a low-power device, but not terrible for something you can build so easily. Plus, it’s waterproof, dust-resistant, and quite robust!

These ESP32 camera modules are seriously nifty – we see them put to good use on the regular. Whether you need to detect motion in your Halloween project, decode your water meter readings, or perhaps merely a security camera, it’s worth having a few in your toolbox. Maybe even pick up a programming helper for these while you’re at it!

Ultra-Low Power, Energy Harvesting Battery Charger

This half-inch square ultra-low power energy harvesting LiPo cell charger by [Kris Winer] uses a low voltage solar panel to top up a small lithium-polymer cell, which together can be used as the sole power source for projects. It’s handy enough that [Kris] uses them for his own projects and offers them for sale to fellow hackers. It’s also his entry into the Power Harvesting Challenge of the Hackaday Prize.

The board is essentially a breakout board for the Texas Instrument BQ25504, configured to charge and maintain a single lithium-polymer cell. The BQ25504 is an integrated part that takes care of most of the heavy lifting and has nifty features like battery health monitoring and undervoltage protection. [Kris] has been using the board along with a small 2.2 Volt solar panel and a 150 mAh LiPo cell to power another project of his: the SensorTile environmental data logger.

It’s a practical and useful way to test things; he says that an average of 6 hours of direct sunlight daily is just enough to keep the 1.8 mA SensorTile running indefinitely. These are small amounts of power, to be sure, but it’s free and self-sustaining which is just what a remote sensing unit needs.