Summary

BEE socket1

Power

M32 uses 5v power from ms14. The mega32u4 avr is powered by 5v as well. M32 provides 5V or 3.3V output power. 

5V: The 5V output power pin is 1+ and 6+

3.3V:  pin 6+ can be used for 3.3v power output, by using the VOUT_SEL jumper. 

GND: 2 GND pins are available in 1- and 6-. 

Input and Output Pins

Each of the 10 digital i/o pins on the m32 can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms. In addition, some pins have specialized functions:

• TWI: 2 (SDA) and 3 (SCL). Support I2C / TWI communication using the Wire library.
• External Interrupts: 3 (interrupt 0), 2 (interrupt 1). These pins can be configured to trigger an interrupt on a low value, a rising or falling edge, or a change in value. See the attachInterrupt() function for details. 
• PWM: 3, 6, 9, 10. Provide 8-bit PWM output with the analogWrite() function.
• LED: 13. The "heart beat" LED is connected to digital pin 13. When the pin is HIGH value, the LED is on, when the pin is LOW, it's off.
• Analog Inputs: A0 - A3, [A6, A8, A10, A11 (on digital pins 4, 6, 9 and 10)]. The m32 has 8 analog inputs, all of which can also be used as digital i/o. Each analog input provide 10 bits of resolution (i.e. 1024 different values). The analog inputs measure from ground to 5 volts. 
• RESET_MS14:11(PB7): Bring this line LOW to reset the AR9331 microprocessor on ms14. Resetting the AR9331 will cause the reboot of the ms14. All the data stored in RAM will be lost and all the programs that are running will be terminated. The reset feature is deactivate by default to avoid error program on 11. Solder a 0ohm capacitor on R14 or short the two ends of this resister will active this feature. 

ESD and Overvoltage Protection

Except 7+ and 7- , all other pins are Overvoltage and ESD protected following the standard IEC 61000-4-2. 

Internal Connectors

The M32 has two on board connectors which are reserve for further development.

• I2C Connector: This 1x4 (2.54mm) connector has SCL/SDA/5V/GND pin out, it can used to hook up a small I2C PCB and place into MS14. 
• J2 Connector: This connector is reserved for further process the signal on 7+ and 7- pins.

USB Connector

M32 has a micro USB connector and can act as standard USB COM device. This USB connection can be used to upgrade firmware or debug the software via serial monitor on Arduino IDE.