published 24.07.2019

SolarCamPi is an off-grid webcam solution, that can take a picture using a Raspberry Pi Camera or a USB webcam every 5 minutes and send the image over a long-distance WiFi link.

Using a specially modified Linux image on the Raspberry Pis SD card, booting, taking a picture and sending it over wifi can be done in under 15 seconds. This allows the Raspberry Pi to be powered off most of the time, thus saving energy.

A small 5W solar panel with a 16F, 16V ultracapacitor bank can run this setup permanently, even at night.

Technical specs:
— 15s runtime with 200mA current draw
— 15Ws energy per picture
— Undervoltage lockout
— Image upload via HTTP Post
— Voltage reporting via HTTP Post
— Configurable parameters via I2C
— Wide input voltage range: 3V to 18V
— Low idle/quiescence current: 11µA

— Using ATmega328 (main MCU), INA119 (power measurement), TPS71533 (LDO), TPS63070 (buck boost)

PCB - Revision C - Bill of materials:
PCB - Errata:

GitHub Repository (Firmware, PCB layout, Linux scripts):

RevB board:

Pictures of the development process (prototype, RevA):