The Arduino Micro is a microcontroller board based on the ATmega32u4 , developed in conjunction with Adafruit. It has 20 digital input/output pins (of which 7 can be used as PWM outputs and 12 as analog inputs), a 16MHz crystal oscillator, a micro USB connection, an ICSP header, and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a micro USB cable to get started. It has a form factor that enables it to be easily placed on a breadboard.
The Arduino Micro USB Microcontroller a microcontroller board based on the ATmega32u4, developed in conjunction with Adafruit.
The Arduino Micro can be powered via the micro USB connection or with an external power supply. The power source is selected automatically. External (non-USB) power can come either from a DC power supply or battery. Leads from a battery or DC power supply can be connected to the Gnd and Vin pins.
The board can operate on an external supply of 6 to 20 volts. If supplied with less than 7V, however, the 5V pin may supply less than five volts and the board may be unstable. If using more than 12V, the voltage regulator may overheat and damage the board. The recommended range is 7 to 12 volts.
The ATmega32u4 has 32 KB (with 4 KB used for the bootloader). It also has 2.5 KB of SRAM and 1 KB of EEPROM (which can be read and written with the EEPROM library).
Input and Output
Each of the 20 digital i/o pins on the Micro can be used as an input or output, using pinMode(), digitalWrite(), anddigitalRead() 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:
· Seri: 0 (RX) and 1 (TX).
· TWI: 2 (SDA) and 3 (SCL).
· PWM: 3, 5, 6, 9, 10, 11 and 13.
· LED: 13
· Analog Inputs: A0-A5, A6 – A11 (on digital pins 4, 6, 8, 9, 10, and 12).