I’d like to be able to read some environmental sensors and control some low power outdoor devices using the nRF52832. While I am aware that the nRF52 can operate for a long time on one 18650 battery, I’d like to extend this run time indefinitely by adding a single 0.5W to 1W solar panel. I have calculated the additional material cost (for the solar panel and linear charge controller) at less than $2.5 so it is a worthwhile investment.
I can build this myself but before I go down this path, I’d like to see if there is an existing design that I can re-use or improve on.
I intend to include:
- MPPT solar charge controller (probably linear, but possibly switching, depending on performance and cost difference)
- Solar panel current sensor
- Solar panel voltage sensor
- Battery current sensor
- Battery voltage sensor
- Ability to shutdown all 4 power sensors, to conserve power, while sleeping (depending on cost of switches vs. just using a bigger solar panel)
- Calculate approximate battery state of charge and remaining run time
- Transmit this data via BLE
Is anybody building, or has built, anything similar and has a design that they can share?
I also welcome any questions or comments.
