empowering creative people

Arduino > Official

Arduino Mega 2560 R3

SKU: A000067

$74.95 AUD, inc GST

More Views

Arduino Mega 2560 R3
74.95 AUD

SKU: A000067

$74.95 AUD, inc GST
2 reviews 0 5 5
Ships today (delivered by Mon, 5th of Dec)
Shipping Offer

OR

The Arduino Mega 2560 is a microcontroller board based on the ATmega2560 (datasheet). 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. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started. The Mega is compatible with most shields designed for the Arduino Duemilanove or Diecimila.

The Mega 2560 is an update to the Arduino Mega, which it replaces.

The Mega2560 differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip. Instead, it features the ATmega16U2 (ATmega8U2 in the revision 1 and revision 2 boards) programmed as a USB-to-serial converter.

Revision 2 of the Mega2560 board has a resistor pulling the 8U2 HWB line to ground, making it easier to put into DFU mode.

Revision 3 of the board has the following new features:

  • 1.0 pinout: added SDA and SCL pins that are near to the AREF pin and two other new pins placed near to the RESET pin, the IOREF that allow the shields to adapt to the voltage provided from the board. In future, shields will be compatible both with the board that use the AVR, which operate with 5V and with the Arduino Due that operate with 3.3V. The second one is a not connected pin, that is reserved for future purposes.
  • Stronger RESET circuit.
  • Atmega 16U2 replace the 8U2.

Arduino MEGA 2560 Specifications

Power

The Arduino Mega 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 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 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.

Memory

The ATmega2560 has 256 KB of flash memory for storing code (of which 8 KB is used for the bootloader), 8 KB of SRAM and 4 KB of EEPROM (which can be read and written with the EEPROM library).

Input and Output

Each of the 54 digital pins on the Mega 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:

  • Serial 0: (RX) and 1 (TX); 
  • Serial 1: 19 (RX) and 18 (TX); 
  • Serial 2: 17 (RX) and 16 (TX); 
  • Serial 3: 15 (RX) and 14 (TX). Used to receive (RX) and transmit (TX) TTL serial data. Pins 0 and 1 are also connected to the corresponding pins of the ATmega16U2 USB-to-TTL Serial chip.
  • External Interrupts: 2 (interrupt 0), 3 (interrupt 1), 18 (interrupt 5), 19 (interrupt 4), 20 (interrupt 3), and 21 (interrupt 2). 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: 2 to 13 and 44 to 46. Provide 8-bit PWM output with the analogWrite()function.
  • SPI: 50 (MISO), 51 (MOSI), 52 (SCK), 53 (SS). These pins support SPI communication using the SPI library. The SPI pins are also broken out on the ICSP header, which is physically compatible with the Uno, Duemilanove and Diecimila.
  • LED: 13. There is a built-in LED connected to digital pin 13. When the pin is HIGH value, the LED is on, when the pin is LOW, it's off.
  • TWI: 20 (SDA) and 21 (SCL). Support TWI communication using the Wire library. Note that these pins are not in the same location as the TWI pins on the Duemilanove or Diecimila. 

The Mega2560 has 16 analog inputs, each of which provide 10 bits of resolution (i.e. 1024 different values). By default they measure from ground to 5 volts, though is it possible to change the upper end of their range using the AREF pin and analogReference() function.

There are a couple of other pins on the board:

  • AREF. Reference voltage for the analog inputs. Used with analogReference(). 
  • Reset. Bring this line LOW to reset the microcontroller. Typically used to add a reset button to shields which block the one on the board.

Communication

The Arduino Mega2560 has a number of facilities for communicating with a computer, another Arduino, or other microcontrollers. The ATmega2560 provides four hardware UARTs for TTL (5V) serial communication. An ATmega16U2 (ATmega 8U2 on the revision 1 and revision 2 boards) on the board channels one of these over USB and provides a virtual com port to software on the computer (Windows machines will need a .inf file, but OSX and Linux machines will recognize the board as a COM port automatically. The Arduino software includes a serial monitor which allows simple textual data to be sent to and from the board. The RX and TX LEDs on the board will flash when data is being transmitted via the ATmega8U2/ATmega16U2 chip and USB connection to the computer (but not for serial communication on pins 0 and 1).

A SoftwareSerial library allows for serial communication on any of the Mega2560's digital pins.

The ATmega2560 also supports TWI and SPI communication. The Arduino software includes a Wire library to simplify use of the TWI bus; For SPI communication, use the SPI library.

Programming

The Arduino Mega can be programmed with the Arduino software (download).

The ATmega2560 on the Arduino Mega comes preburned with a bootloader that allows you to upload new code to it without the use of an external hardware programmer. It communicates using the original STK500 protocol.

You can also bypass the bootloader and program the microcontroller through the ICSP (In-Circuit Serial Programming) header using Arduino ISP or similar; 

The ATmega16U2 (or 8U2 in the rev1 and rev2 boards) firmware source code is available in the Arduino repository. The ATmega16U2/8U2 is loaded with a DFU bootloader, which can be activated by:

  • On Rev1 boards: connecting the solder jumper on the back of the board (near the map of Italy) and then resetting the 8U2.
  • On Rev2 or later boards: there is a resistor that pulling the 8U2/16U2 HWB line to ground, making it easier to put into DFU mode. You can then use Atmel's FLIP software (Windows) or the DFU programmer (Mac OS X and Linux) to load a new firmware. Or you can use the ISP header with an external programmer (overwriting the DFU bootloader). 

Automatic (Software) Reset

Rather then requiring a physical press of the reset button before an upload, the Arduino Mega2560 is designed in a way that allows it to be reset by software running on a connected computer. One of the hardware flow control lines (DTR) of the ATmega8U2 is connected to the reset line of the ATmega2560 via a 100 nanofarad capacitor. When this line is asserted (taken low), the reset line drops long enough to reset the chip. The Arduino software uses this capability to allow you to upload code by simply pressing the upload button in the Arduino environment. This means that the bootloader can have a shorter timeout, as the lowering of DTR can be well-coordinated with the start of the upload.

This setup has other implications. When the Mega2560 is connected to either a computer running Mac OS X or Linux, it resets each time a connection is made to it from software (via USB). For the following half-second or so, the bootloader is running on the Mega2560. While it is programmed to ignore malformed data (i.e. anything besides an upload of new code), it will intercept the first few bytes of data sent to the board after a connection is opened. If a sketch running on the board receives one-time configuration or other data when it first starts, make sure that the software with which it communicates waits a second after opening the connection and before sending this dat

The Mega2560 contains a trace that can be cut to disable the auto-reset. The pads on either side of the trace can be soldered together to re-enable it. It's labeled "RESET-EN". You may also be able to disable the auto-reset by connecting a 110 ohm resistor from 5V to the reset line.

USB Overcurrent Protection

The Arduino Mega2560 has a resettable polyfuse that protects your computer's USB ports from shorts and overcurrent. Although most computers provide their own internal protection, the fuse provides an extra layer of protection. If more than 500 mA is applied to the USB port, the fuse will automatically break the connection until the short or overload is removed.

Physical Characteristic

The maximum length and width of the Mega2560 PCB are 4 and 2.1 inches respectively, with the USB connector and power jack extending beyond the former dimension. Three screw holes allow the board to be attached to a surface or case. Note that the distance between digital pins 7 and 8 is 160 mil (0.16"), not an even multiple of the 100 mil spacing of the other pins.

The Mega2560 is designed to be compatible with most shields designed for the Uno, Diecimila or Duemilanove. Digital pins 0 to 13 (and the adjacent AREF and GND pins), analog inputs 0 to 5, the power header, and ICSP header are all in equivalent locations. Further the main UART (serial port) is located on the same pins (0 and 1), as are external interrupts 0 and 1 (pins 2 and 3 respectively). SPI is available through the ICSP header on both the Mega2560 and Duemilanove / Diecimila. Please note that I2C is not located on the same pins on the Mega (20 and 21) as the Duemilanove / Diecimila (analog inputs 4 and 5).

This product is listed in:

Documentation and Resources:
  • Arduino Boards, Compared
  • There are a bunch of Arduino boards, they come in different shapes and sizes, with different processing power, digital IO, and other capabilities. Rather than telling you guys what to buy, we have put together a handy guide to show you the capabiliti...
  • Arduino vs. Raspberry Pi
  • One of the big questions in DIY electronics circles is which DIY platform is going to be the best for me? And the two biggest platforms right now is Arduino and Raspberry Pi. Whilst at first glance they might seem the same; circuit board with some el...
  • Arduino, Learn the Lingo
  • Getting into the Arduino environment is a lot of fun but with so many acronyms and slang terms its easy to get confused. Knowing this first hand, I have put together a glossary of sorts for terms relating to Arduino, if you are new to the Arduino pla...
  • Our Arduino SPI Tutorial
  • SPI stands for Serial Peripheral Interface and it is a way to send data between microcontrollers and other small devices. It is a synchronous data bus, meaning it uses a clock to regulate the data transfer. SPI is also Full-Duplex communication mean...
  • Arduino with LattePanda
  • Ah, Arduino and LattePanda coming together at last. What could be better? Well along with the fact that your LattePanda is a fully fledged Windows 10 computer so you can program any Arduino board you want as normal, one of the best things about Latte...
  • Coffee Grinder With Arduino
  • Using a few bits and pieces, this ordinary coffee grinder now has two presets to run the motor for a programmable length of time. The idea being that the grinder running for a set amount of time will deliver a certain amount of coffee each button press meaning the beans can be stored unground, keeping them fresher for longer. I completed this project for a friend, Ian, who lives for coffee. Ian wanted the same functionality in h...
  • The Hipster Coaster
  • We wanted to make a interactive display of the fun that can be had with DIY projects to take to Sydney Mini Maker Faire. We decided to do so by utilising the TinkerKit Braccio from Arduino.org, alongside some 3D Printing ingenuity, for an engaging display for all ages. Enter the Hipster Coaster in all its glory.   All the parts were printed seperately on our family of Lulzbot 3D Printers, later stuck together using a mi...

Product Comments

Documentation and Resources:
  • Arduino Boards, Compared
  • There are a bunch of Arduino boards, they come in different shapes and sizes, with different processing power, digital IO, and other capabilities. Rather than telling you guys what to buy, we have put together a handy guide to show you the capabiliti...
  • Arduino vs. Raspberry Pi
  • One of the big questions in DIY electronics circles is which DIY platform is going to be the best for me? And the two biggest platforms right now is Arduino and Raspberry Pi. Whilst at first glance they might seem the same; circuit board with some el...
  • Arduino, Learn the Lingo
  • Getting into the Arduino environment is a lot of fun but with so many acronyms and slang terms its easy to get confused. Knowing this first hand, I have put together a glossary of sorts for terms relating to Arduino, if you are new to the Arduino pla...
  • Our Arduino SPI Tutorial
  • SPI stands for Serial Peripheral Interface and it is a way to send data between microcontrollers and other small devices. It is a synchronous data bus, meaning it uses a clock to regulate the data transfer. SPI is also Full-Duplex communication mean...
  • Arduino with LattePanda
  • Ah, Arduino and LattePanda coming together at last. What could be better? Well along with the fact that your LattePanda is a fully fledged Windows 10 computer so you can program any Arduino board you want as normal, one of the best things about Latte...
  • Coffee Grinder With Arduino
  • Using a few bits and pieces, this ordinary coffee grinder now has two presets to run the motor for a programmable length of time. The idea being that the grinder running for a set amount of time will deliver a certain amount of coffee each button press meaning the beans can be stored unground, keeping them fresher for longer. I completed this project for a friend, Ian, who lives for coffee. Ian wanted the same functionality in h...
  • The Hipster Coaster
  • We wanted to make a interactive display of the fun that can be had with DIY projects to take to Sydney Mini Maker Faire. We decided to do so by utilising the TinkerKit Braccio from Arduino.org, alongside some 3D Printing ingenuity, for an engaging display for all ages. Enter the Hipster Coaster in all its glory.   All the parts were printed seperately on our family of Lulzbot 3D Printers, later stuck together using a mi...

Customer Reviews

  1. Review by Phong - Excellent verified purchaser
    Rating
    100

    Genuine and Fast delivery! (Posted on 8/03/2014)

  2. Review by Michael - Great product verified purchaser
    Rating
    100

    Purchased this along with the UNO.
    Product was in stock and fast delivery. (Posted on 9/09/2013)

We deliver Australia-wide with these options:

  • $3 for Small Items (4-6 days, not tracked, only available on selected small items)
  • $6.95 for Standard Post (2-4 days, tracked)
  • $8.32 for Express Post (1-2 days, tracked)

If you order lots of gear, the postage amount might increment based on the weight of your order.

Our physical address (no pickups sorry!):

Unit 18, 132 Garden Grove Parade
Adamstown
NSW, 2289
Australia

Please checkout our customer service page if you have other frequently asked questions such as "do we do purchase orders" (yes!) or "are prices GST inclusive" (yes they are!). We're here to help - get in touch with us to talk shop.