(png version)

A more complete list of the functions the pins can do can be found in table 17 (page 51) of the datasheet.

• Ground
• USBv+ - Direct line to USB power.
• Batt+ - Direct line to the battery.
• 3.3v - The regulated 3.3v output. (300mA max)
• Vin - Either Batt+ or USBv+ (if connected), and controlled by the On/Off switch.

There are 4 high-power outputs, which are each powered by a MOSFET to ground and can drive up to 2.3A, each. The usual circuit is to connect the anode (+) of an LED to Batt+ and the cathode (-) side to one of these outputs. Then simply drive the pin with the microcontroller.

• PA0 - LED1
• PA1 - LED2
• PA2 - LED3
• PA3 - LED4

• PB4 - Tactile button
• PA11 - USB D-
• PA12 - USB D+

Other general-purpose IO pins:

• PA4
• PA5
• PA6
• PA7
• PA8
• PA9
• PA10
• PA13
• PA14
• PB5
• PB6
• PB7