- The Arduino MEGA ADK is a microcontroller board based on the ATmega2560.
- It has a USB host interface to connect with Android based phones, based on the MAX3421e IC.
- It has 54 digital input/output pins (of which 15 can be used as PWM outputs),
- 16 analog inputs,
- 4 UARTs (hardware serial ports),
- a 16 MHz crystal oscillator,
- a USB connection,
- a power jack,
- an ICSP header, and
- a reset button.
The Arduino MEGA ADK can be powered via the USB connection or with an external power supply. The power source is selected automatically.
External (non-USB) power can come either from an AC-to-DC adapter (wall-wart) or battery.
The adapter can be connected by plugging a 2.1mm center-positive plug into the board’s power jack.
Leads from a battery can be inserted in the Gnd and Vin pin headers of the POWER connector.
The power pins are as follows:
- VIN. The input voltage to the Arduino board when it’s using an external power source (as opposed to 5 volts from the USB connection or other regulated power source). You can supply voltage through this pin, or, if supplying voltage via the power jack, access it through this pin.
- 5V. This pin outputs a regulated 5V from the regulator on the board. The board can be supplied with power either from the DC power jack (7 – 12V), the USB connector (5V), or the VIN pin of the board (7-12V). Supplying voltage via the 5V or 3.3V pins bypasses the regulator, and can damage your board. We don’t advise it.
- 3V3. A 3.3 volt supply generated by the on-board regulator. Maximum current draw is 50 mA.
- GND. Ground pins.
- IOREF. This pin on the Arduino board provides the voltage reference with which the microcontroller operates. A properly configured shield can read the IOREF pin voltage and select the appropriate power source or enable voltage translators on the outputs for working with the 5V or 3.3V.