Note: Gravity: IO Expansion Shield for Bluno M3 is discontinued now, we recommend other IO expansion shields as a suitable replacement. Say goodbye to messy cables! This IO shield is a powerful expansion shield for the Bluno M3. The breakouts for digital pins range from D0 to D38, including 5 UARTS, 8 PWM pins and 8 analog pins. The IO Expansion shield uses a convenient color coded 3 pin format for signal, voltage and ground that is useful if used with a large range of devices. The IO expansion shield also integrates an external power connector for servos - if you need to power a large array of servos, use the screw terminals to connect your power supply and drive them directly from your Bluno M3. It will switch to the right power source automatically. An intelligent power regulator allows you to connect a battery and USB cable simultaneously, and an on-board voltage switch makes it easy to change the output voltage, making 3.3V or 5V sensors compatible.