- Icsp +5v gnd +5v gnd gnd +5v gnd gnd 47u 47u gnd gnd g n d gnd green g n d +5v m7 gnd mc33269d-5.0 mc33269st-5.0t3 100n gnd 100n 100n +3v3 +5v +5v atmega1280-16au 100n 100n.
- After doing a quick search, I was unable to find an accurate technical drawing of the new Arduino UNO and Arduino Mega 2560. Using the PCB design files available at the Arduino hardware website, I created a detailed technical drawing of both the Uno and Mega 2560. The drawings are available in vector-based SVG format, but low-resolution PNG.
- The Arduino Mega 2560 is actually a microcontroller board in light of the ATmega2560 (datasheet). It has 54 digital input/output pins (of which 15 can be utilized as PWM outputs), 16 simple inputs, 4 UARTs (hardware serial ports), a 16 MHz crystal oscillator, a USB connection, a power jack, an ICSP header, and a reset button.
This is a project which is reproduced from arduino.cc Arduino Mega 2560. Using EasyEDA to re-layout the PCB. This is a project which is reproduced from arduino.cc Arduino Mega 2560.Using EasyEDA to re-layout the PCB. If the driver for CP2102 was installed, when connected the Naked Mega can be programmed like an original Arduino Mega 2560. Add Tip Ask Question Comment Download. Step 7: Cost Breakdown. Cost Breakdown: PCB: $45.6 for 40, $1.14 for 1. ATmega2560: $6-10 for 1 (price fluchuates greatly).
How to connect a serial port Arduino Mega 2560 R3 to an Arduino UNO R3 compatible and to an Arduino Leonardo clone.
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This tutorial we are covering Serial Port Basics on the Arduino Mega 2560 R3.
If you ever wonder how to use the other Serial ports on the Arduino Mega 2560 R3, but don't know where to start? This short tutorial we'll go over the basics, we'll connect to an Adafruit Metro 328 = its an Arduino compatible; works just like an Arduino UNO R3, and we will connect to an Arduino Leonardo clone...
The connections will be UART to UART, SoftwareSerial to SoftwareSerial, UART to SoftwareSerial, and ALL 3 connected together!! :)
Before you make the physical wire connections.... LOAD the code to your Arduinos first!
Please follow this step because your Arduinos use the 'DEFAULT' SerialPort to upload your code from the Computer, once you make the physical wire connections the 'Default' SerialPort will be used on the Arduino UNO (Adafruit Metro 328) to communicate with the Arduino Mega 2560 R3's SerialPort #1 which is pin19 RX1 and pin18 TX1 on the Mega. This will not allow the Arduino UNO(Adafruit Metro 328) to communicate with the outside world; AKA your computer. The Leonardo will use the SoftwareSerial example but if using the UART; same will apply as the Arduino UNO's....
MEGA to Adafruit 328(Arduino UNO) UART to UART connection.
- Upload the the codes to Arduino Mega and Arduino UNO(Adafruit 328)
- Connect one end of a wire to Mega's pin19 RX1 and the other end to Arduino UNO's(Adafruit 328) pin1 TX...
- Connect one end of a wire to Mega's pin18 TX1 and the other end to Arduino UNO's(Adafruit 328) pin0 RX
- Connect the ground pin on the Mega to the ground pin on the Arduino UNO(Adafruit 328).
- Connect Arduino UNO to a Stable/Reliable power source.
- Connect Arduino Mega to the Computer from the USB cable.
- On the Arduino Mega UART1 program window of the Arduino IDE, make sure your COM is selected to the Arduino Mega before opening the Serial Console, Open the Serial Console set to 9600 baud COM Speed.
- On the Top window in the text box enter the letter x … not the capital X … the LED on the Arduino UNO(Adafruit 328) goes ON.
- On the Top window in the text box enter the letter a … not the capital A … the LED on the Arduino UNO(Adafruit 328) goes OFF.
What we are doing in this code is calling on the Arduino Mega's default UART Serial port by calling Serial.begin at a 9600 baud speed rate. This is going to listen to the Computer for instructions through the USB cable. We are also calling upon the 2nd UART Serial port by calling Serial1.being at a 9600 baud rate. This is going to communicate with the Arduino UNO(Adafruit Metro 328).
What happens.... when you type the letter x or a on the text window on the Serial Console it sends it to the Arduino Mega, then the Arduino Mega sends it to the Arduino UNO(Adafruit Metro 328) through the 2nd UART Serial port with the Serial1.write(Serial.read()); command.
In this code we are using the Arduino UNO (Adafruit Metro 328) default Serial UART to communicate with the Mega, The Arduino waits for the Serial UART to receive a message, if the data is a refence what is in the code, in this case is a letter x or a the code will turn ON or OFF the LED on the Arduino UNO (Adafruit Metro 328).
Arduino Mega to Arduino Leonardo …. SoftSerial to SoftSerial connection.
- Load code to Arduinos
- One end of one wire goes to pin9 of Mega, the other side of wire goes to pin8 of Arduino Leonardo.
- One end of one wire goes to pin9 of Mega, the other side of wire goes to pin9 of Arduino Leonardo.
- One end of one wire goes to Ground pin of Mega, the other side of the wire goes to the Ground pin of Arduino Leonardo.
- Connect a reliable power supply to your Leonardo
- Connect the computer USB cable to your Mega
- On the Arduino Mega SoftSerial window in the Arduino IDE, make sure your comm port is set for the Arduino Mega.
- Open your Serial Console, set it to 9600 baud speed rate if its not there yet, type the letter a on the text box on the top, the light on the Leonardo should go ON, type x on the text box and the light on the Leonardo should go OFF.
In this code we use software serial instead of the hardware UART serial, to communicate with the Leonardo, Pin8 will be RX and pin9 will be TX. Hardware Serial UART is used to communicate with the computer. The same process hapens here; type something in the serial console text window and the computer sends it to the Mega, then the Mega sends it to the Leonardo.
Here we use software serial instead of the hardware serial; pin8 is RX, pin9 is TX, and the same thing happens as the other example; if the letter a is received the LED on the Leonardo is turned ON if the letter x is received the LED is turned OFF.
Arduino Mega Hardware UART to Arduino Leonardo Software Serial
- Keep the same program on the Arduino Leonardo
- Load Arduino Mega UART3 code on the Mega
- connect pin14 TX3 on the Mega to pin8 RX on the Leonardo
- connect pin15 RX3 on the Mega to pin9 TX on the Leonardo
- connect the Leonardo to a reliable power source
- connect the Mega to the computer USB cable
- On the Arduino Mega UART3 code in the Arduino IDE make sure your using the Mega port, Open the serial console when you type a the LED turns ON the Leonardo, when you type an x the LED on the Leonardo turns OFF.
In this code we use UART3 on the Mega to communicate with the Leonardo. Same thing happens as the other example we only used UART #3 on the Mega. The code on the Leonardo remains the same as the previous example.
This is the LAST Example!!!
We will connect ALL 3 together!!!
You may be wondering why would you want to do that?!??!
Because you may find yourself in a situation where your using your default hardware UART for a device and then you need another UART connection; this is where you use the software serial on the same board!!!... you may say.... well I will just use a Mega... Well, … my little programmer, not ALL shields or sensors are compatible with the Mega; that's why were are going to connect the Arduino UNO (Adafruit Metro 328) as an In-between microcontroller just for this reason.... You'll thank me later when the issue arrives..
- To save time and energy, the Mega keeps the same program and the Leonardo keeps the same program from the last example.
- We just need to upload the new program to the Arduino UNO (Adafruit Metro 328)
- Upload Arduino UNO UART___SoftSerial code to the Arduino UNO(Adafruti Metro 328)
- connect pin9 TX on the Leonardo to pin8 RX on the Arduino UNO(Adafruit Metro 328) this is for Software Serial
- connect pin8 RX on the Leonardo to pin9 TX on the Arduino UNO(Adafruti Metro 328) this is for Software Serial
- connect pin14 TX3 on the Mega to pin0 RX on the Arduino UNO(Adafruit Metro 328) this is for Hardware Serial UART
- connect pin15 RX3 on the Mega to pin1 TX on the Arduino UNO (Adafruit Metro 328)
- connect ALL 3 Micros ground pins together
- connect Leonardo and UNO (Adafruit Metro 328) to a reliable power source
- connect Mega to computers USB cable
- On the Arduino Mega UART3 code IDE make sure your Mega comm port is selected.
- Open the Serial Monitor use 9600 baud speed, when you type the letter v on the text window the LED on the UNO (Adafruit Metro 328) goes ON. Whe you type the letter b the LED goes OFF.
- When you type the letter a on the text window the computer sends it to the Mega then the Mega sends it to the UNO (Adafruti Metro 328) then the UNO (Adafruit Mero 328) sends it to the Leonardo to turn ON the LED on the Leonardo. Type the letter x and the LED on the Leonardo goes OFF
Here you can see how softSerial is declared and used, when the letter x is recieved, softSerial will send a letter x to the Leonardo, same for the letter a.
Arduino UNO (Adafruit Metro 328) SLAVE UARTArduino
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Published onSeptember 16, 2019
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Arduino 2560 Schematic
Table of contents
The Arduino Mega 2560 is a microcontroller board based on the ATmega2560. 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 2560 board is compatible with most shields designed for the Uno and the former boards Duemilanove or Diecimila.
The Mega 2560 is an update to the Arduino Mega, which it replaces.
If you are looking at upgrading from previous Arduino designs, or if you are just interested in boards with similar functionality, at Arduino you can find:
- Uno Rev 3
- Arduino Nano
- Arduino DUE without headers
Find inspiration for your projects with the Mega 2560 board from our tutorial platform Project Hub.
You can find in the Getting Started with Arduino MEGA2560 Rev 3 section all the information you need to configure your board, use the Arduino Software (IDE), and start tinkering with coding and electronics.
From the Tutorials section you can find examples from libraries and built-in sketches as well other useful information to expand your knowledge of the Arduino hardware and software.
Check the Arduino Forum for questions about the Arduino Language, or how to make your own Projects with Arduino. Need any help with your board please get in touch with the official Arduino User Support as explained in our Contact Us page.
You can find here your board warranty information.
|Input Voltage (recommended)||7-12V|
|Input Voltage (limit)||6-20V|
|Digital I/O Pins||54 (of which 15 provide PWM output)|
|Analog Input Pins||16|
|DC Current per I/O Pin||20 mA|
|DC Current for 3.3V Pin||50 mA|
|Flash Memory||256 KB of which 8 KB used by bootloader|
|Clock Speed||16 MHz|
Arduino Mega 2560 is open-source hardware! You can build your own board using the following files:
Arduino Mega 2560 Proteus Schematic Pinout
Download the full pinout diagram as PDF here.
Interactive Board Viewer
The Mega 2560 board can be programmed with the Arduino Software (IDE). For details, see thereference and tutorials.
The ATmega2560 on the Mega 2560 comes preprogrammed 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 (reference, C header files).
You can also bypass the bootloader and program the microcontroller through the ICSP (In-Circuit Serial Programming) header using Arduino ISP or similar; see these instructions for details.
The ATmega16U2 (or 8U2 in the rev1 and rev2 boards) firmware source code is available in theArduino 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). See this user-contributed tutorial for more information.
The Mega 2560 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.
The Mega 2560 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 become 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 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 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.
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
See the mapping between Arduino pins and Atmega2560 ports:
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 20 mA as recommended operating condition and has an internal pull-up resistor (disconnected by default) of 20-50 k ohm. A maximum of 40mA is the value that must not be exceeded to avoid permanent damage to the microcontroller.
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 level, a rising or falling edge, or a change in level. 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 theSPI library. The SPI pins are also broken out on the ICSP header, which is physically compatible with the Arduino /Genuino Uno and the old Duemilanove and Diecimila Arduino boards.
- 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 old Duemilanove or Diecimila Arduino boards.
See also the mapping Arduino Mega 2560 PIN diagram.
The Mega 2560 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.
The Mega 2560 board has a number of facilities for communicating with a computer, another board, 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 (IDE) 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 Mega 2560's digital pins.
The Mega 2560 also supports TWI and SPI communication. The Arduino Software (IDE) includes a Wire library to simplify use of the TWI bus; see the documentation for details. For SPI communication, use the SPI library.
Physical Characteristics and Shield Compatibility
The maximum length and width of the Mega 2560 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 Mega 2560 is designed to be compatible with most shields designed for the Uno and the older Diecimila or Duemilanove Arduino boards. 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. Furthermore, 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 Mega 2560 and Duemilanove / Diecimila boards. Please note that I2C is not located on the same pins on the Mega 2560 board (20 and 21) as the Duemilanove / Diecimila boards (analog inputs 4 and 5).
Automatic (Software) Reset
Rather then requiring a physical press of the reset button before an upload, the Mega 2560 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 (IDE) 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 Mega 2560 board 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 ATMega2560. 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 data.
The Mega 2560 board 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; see this forum thread for details.
The Mega 2560 does not use the FTDI USB-to-serial driver chip used in past designs. Instead, it features the ATmega16U2 (ATmega8U2 in the revision 1 and revision 2 Arduino boards) programmed as a USB-to-serial converter.
Revision 2 of the Mega 2560 board has a resistor pulling the 8U2 HWB line to ground, making it easier to put into DFU mode.
Revision 3 of the Arduino board and the current Genuino Mega 2560 have the following improved features:
- 1.0 pinout: SDA and SCL pins - 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 board that uses ATSAM3X8E, 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.