Raspberry Pi has a simple power supply solution – via microUSB port. This is great for prototyping but in real applications you would probably like more control. If your end device is battery or solar powered you should implement some king of power monitor-controller.
Kevin Sangeelee has been working on Raspberry Pi power controller based on PIC microcontroller. Power controller is connected to Raspberry Pi as I2C slave and has following features:
- Power the Raspberry Pi off and on with a push-button;
- Fully shut down the Raspberry Pi on ‘shutdown -h’;
- Wake-up at a specified time (one-off or periodic);
- Monitor the supply voltage;
- Log glitches in the power-supply (e.g. caused by USB device activity);
- Maintains the time from a CR2032 button cell.
Project is still on breadboard and software is under development, but it already shows promising results.