This is Version TWO of the USB PowerControl. Version ONE is here.
Note: If you leave the Grove Connector unconnected, Version Two behaves exactly like Version One.
The USB PowerControl board is a USB to USB solid state relay. It is is a digitally controlled power switch for your Arduino or Raspberry Pi. It is a Pi On and Off switch.
We have now added a Grove Digital Input that allows you to control the USB PowerControlV2 using two GPIO Lines (one enable and one control line) to switch on and off from a Grove Digital Port. The Grove Enable Line, when high, disables the LIPOBATIN line and makes control of the device under the Grove Control Line. When the Grove Enable Line is low, the LIPOBATIN line controls the relay as in the original USB PowerControl. The Grove Enable Line is pulled down by a 43K resistor so if it is disconnected, the USB PowerControlV2 is compatible with the original USB PowerControl.
This circuitry is provided to allow the USB PowerControlV2 to be controlled by either LIPOBATIN or the state of the CONTROL Line (J3 Pin 1). ENABLE (J3 Pin 2) controls whether the USB POWERCONTROLV2 is switched by LIPOBATIN or the CONTROL line. Remember that LIPOBATIN is not a digital input. It is designed to look at the voltage level of the battery.
The truth table for the USB PowerControl V2 is given below:
The WatchDog board and the USB PowerControl board are often used together.
If you look at the pin locations diagram in the USB PowerControl specification, you will see the TP3 test pad marked. This is the COut / TP3 signal mentioned in the specification. It is also clearly marked on the board itself. Since it is in an image, a keyword search will not find it.
USB PowerControl Application Diagram