The IOIO-OTG board contains the following components:
USB connector (micro-AB, female): Used to connect to host computer, an Android device or a Bluetooth dongle.
Power jack (2-pin JST, female): Used for power supply to the board. Voltage between 5V-15V should be supplied.
GND pins (10 pins): Ground connection.
VIN pins (3 pins): Used for outputting the supply voltage to your circuit, or as an alternative input to the power jack.
5V pins (3 pins): 5V output from the on-board regulator, which can be used in your circuit.
3.3V pins (3 pins): 3.3V from the on-board regulator, which can be used in your circuit.
I/O pins (46 pins, numbered 1-46): General purpose I/O pins. Some have special functions, see artwork on back of PCB.
PWR LED (red): Lights when the IOIO is getting power.
STAT LED (yellow): General purpose on-board LED, under application control.
MCLR pin: Not normally used. Its purpose is for programming new bootloader firmware on the IOIO board.
BOOT pin: Not normally used. Special pin used for getting the IOIO into bootloader mode on power-up. Note that this pin is shared with the stat LED.
Charge current trimmer (CHG): Adjusts the amount of current supplied on the VBUS line of the USB when acting as a USB host (or when it is connected to your Android). Typically used in battery-powered application with Android to prevent the Android from draining the battery quickly. Turning in the (+) direction increases charge current.
Not normally used. Keep switch in A mode. Host switch: In "A" mode, the IOIO-OTG will detect whether it should act as host or as device automatically, according to whichever USB connector is plugged in (micro-A or micro-B). To support non-standard USB cables or adapters that use micro-B type, move the switch to the "H" position to force host mode.