Solar-Powered Sensor Grid with Supercapacitor Energy Storage Could Last for a Century

An unusual project from Hackaday user sciencedude1990, would see a mesh of solar-powered sensors with supercapacitor energy storage, be deployed all over the globe to detect and measure the point when the Earth’s magnetic field flips. Known as a geomagnetic reversal, the flip interchanges the positions of magnetic north and south, which are random, and have changed positions 183 times over the last 83 million years, and scientists say we’re due for another.

sciencedude1990’s goal is to create a solar-powered wireless sensor grid, capable of running 24/7 and lasting over 100 years, a lofty goal, but not out of the realm of possibility. Each node in the grid uses photovoltaic cells that feed the suns energy into a small conditioning circuit to aid and protect the other circuits in the platform. The power is then transferred to a supercapacitor charger that fills a couple of 50 F supercaps with PTC fuses to regulate the output, which is then fed to an energy-harvesting DC/DC converter, providing a constant 5V output.

After power has been conditioned and regulated, it’s then used to provide juice to an ATmega256RFR2 board outfitted with an SMD chip antenna, an LSM303 (accelerometer/magnetometer), UART multiplexor, and several load switches to power different accessories, including a SAM-M8Q-0–10-based GPS/RF unit scienceguy1990 designed for uploading data to a local base station. All hardware is packed into a clear weatherproof container with the solar cells affixed to the top using 3D printed braces.

The ATmega256RFR2 was programmed using Atmel Studio, and every few seconds, a watchdog timer wakes the microcontroller to read the sensors and check on the supercapacitors. If everything is functioning correctly, the GPS module is activated, and the location/UTC information is recorded and sent wirelessly to the base station (another ATmega256RFR2). Anyone interested in scienceguy1990’s solar power sensor can follow his project page for updated information.