The Open Solar Project Controller
This controller works with 12-82V solar panels and provides MQTT data tracking.
Hacker Tim O'Brien wanted to charge his eWheel (like an e-bike, but with one wheel) using solar. After finding a 2x1 meter solar panel capable of a 450W output for sale on Craigslist for $50, he got to work creating his own Open Solar Project Controller.
Like any solar panel, the device outputs power in DC, and instead of converting it to AC, to be converted back to DC with little wall-mounted adapters, he’s keeping things DC. This allows for charging of small e-transportation, as well as electronics like a laptop or lights without the inefficiency of an inverter. This single panel is able to charge his eWheel every night, and power computers during the day, though one would need something like 50x the panel area to charge a Tesla.
The unit employs a custom Maximum Power Point Tracking (MPPT) setup to increase solar output from the panel, via a Drok DKP6012 power converter with ‘secret’ UART functionality. An ESP32 module is used for control, interface, and data output through MQTT.
Hardware is housed in a custom 3D-printed structure with a new 80mm fan to keep everything cool. The controller works with 12 to 82VDC solar panels, and 3 to 60VDC batteries, and is open source so you can modify it as you see fit.