Video Demo of USB Power Control Board

The new SwitchDoc Labs product USB Power Control board is designed to provide a controllable USB Switch for computers and other USB devices. The board switches power on and off to a USB plug. You can connect anything to the USB out connector and control it.

You could also be controlling the USB Power Control from another computer (such as an Arduino) or just to a mechanical switch that is connected to 5V. The possibilities are endless.

We then move the power down from 3.9V to about 3.3V and it shuts the Pi off as predicted. This could be connected to a LiPo battery in a Solar Power System. There is hysteresis built into USB PowerControl (ON at 3.9V / OFF at ~3.3V) to make sure you aren’t just ping ponging on and off (that is what seems to have killed Project Curacao last November).

Our test system below consisted of a SunAirPlus Solar Power Controller board driving a USB PowerControl board connected to a Raspberry Pi B+. We connected the control pin on the USB PowerControl to a variable power supply. First we ran the power supply up to 3.9V and it turned on as promised. The Raspberry Pi B+ booted correctly and started running supplied by power from the SunAirPlus board. We then shutdown the Raspberry Pi B+ (sudo halt) as it is never good to just remove the power while the Pi is still running. It leads to SD card corruption which is never fun.