Arduino mega 2560 wiring diagram. How to make a smart home on Arduino with your own hands. Scheme, datasheet, pinout

Brushed Motor Controller IC, IR Remote Control, NRF24L01 Radio Module, OKI 120A2, SD Card Module, Brushed Motor Controller IC, M590E GSM GPRS Modem, Real Time Clock DS 3231/DS 1307, Mini 360 on LM2596, L293D, Infrared Sensors distances, Real time clock, HC-SR501, Mini 360 power supply based on LM2596 scheme, L298N controller, HC-SR501, GSM GPRS, M590E GSM GPRS modem, Real time clock DS 3231/DS 1307, ESP8266-12E Wi-Fi module, Card Module, Power supply, Mini 360, L293D, Mini 360 power supply in LM2596 scheme, Radio module, IR remote control, IR remote control, Ethernet shield, Brushed motor controller IC, Brushed motor controller IC, IR remote control, SD Card Module, NRF24L01 Radio Module, OKI Motor, L293D, Stepper Motor, Power Supply, L293D, Mini 360 Power Supply on LM2596, SD Memory Card, Ethernet shield, HC-SR501 Motion Sensor, ESP8266-12E Wi-Fi Module, Stepper OKI 120A2 motor, Stepper motor,

The Arduino Mega is based on the ATmega2560 microcontroller.

Arduino Mega2560 board

Arduino Mega2560 board specifications

microcontroller	ATmega2560
Working voltage	5 V
	7-12V
Input voltage (limit)	6-20V
Digital inputs/outputs	54 (14 of which can work as PWM outputs)
Analog inputs
DC current through input/output	40 mA
DC for 3.3V output	50 mA
Flash memory	256 KB, of which 8 KB are used for the bootloader
RAM	8 KB
EEPROM	4 KB
Clock frequency	16 MHz

General information

Arduino Mega 2560 is a device based on the ATmega2560 microcontroller. It includes everything you need to conveniently work with the microcontroller: 54 digital inputs / outputs (of which 15 can be used as PWM outputs), 16 analog inputs, 4 UARTs (hardware transceiver for implementation of serial interfaces), a 16 MHz crystal, a USB connector, a power connector, an ICSP connector for in-circuit programming, and a reset button. To start working with the device, simply supply power from an AC/DC adapter or battery, or connect it to a computer via a USB cable. The Arduino Mega is compatible with most expansion boards designed for the Arduino Duemilanove and Diecimila.

The Mega 2560 is an updated version of the Arduino Mega.

The Arduino Mega 2560 differs from all previous boards in that it uses the ATmega16U2 microcontroller instead of the FTDI chip to convert the USB-UART interfaces (ATmega8U2 in the R1 and R2 versions of the board).

On the Mega 2560 version R2 board, a resistor is added to pull the HWB line of the 8U2 microcontroller to ground. Such a measure makes it possible to simplify the process of updating the firmware and switching the device to DFU mode.

The changes on the R3 board are listed below:

Pinout 1.0: Added SDA and SCL pins (near the AREF pin), as well as two new pins located near the RESET pin. The first - IOREF - allows expansion boards to adapt to the operating voltage of the Arduino. This pin is provided for compatibility of expansion boards with both 5V Arduino based on AVR microcontrollers and 3.3V Arduino Due boards. The second pin is not connected to anything and is reserved for future use.

Improved noise immunity of the reset circuit.

Microcontroller ATmega16U2 replaced by 8U2.

Diagram, original design and pinout

Pinout: PinMap2560

Nutrition

Arduino Mega can be powered from USB or from an external power source - the type of source is selected automatically.

An external AC/DC adapter or battery/battery can be used as an external power source (not USB). The adapter plug (diameter - 2.1mm, center pin - positive) must be inserted into the corresponding power connector on the board. In the case of battery/battery power, its wires must be connected to the Gnd and Vin terminals of the POWER connector.

The voltage of the external power supply can be in the range from 6 to 20 V. However, a decrease in the supply voltage below 7V leads to a decrease in the voltage at the 5V pin, which can cause the device to become unstable. Using a voltage greater than 12V can lead to overheating of the voltage regulator and failure of the board. With this in mind, it is recommended to use a power supply with a voltage in the range of 7 to 12V.

The power pins located on the board are listed below:

VIN. Voltage supplied to the Arduino directly from an external power supply (not related to 5V from USB or other regulated voltage). Through this output, you can both supply external power and consume current when the device is powered from an external adapter.

5V. This pin receives a voltage of 5V from the voltage regulator on the board, regardless of how the device is powered: from the adapter (7 - 12V), from USB (5V) or through the VIN pin (7 - 12V). It is not recommended to power the device through 5V or 3V3 pins, since in this case a voltage regulator is not used, which can lead to failure of the board.

3v3. 3.3V coming from the voltage regulator on the board. The maximum current drawn from this pin is 50 mA.

GND. Ground conclusions.

IOREF. This pin provides the expansion boards with information about the operating voltage of the Arduino microcontroller. Depending on the voltage read from the IOREF pin, the expansion board can switch to the appropriate power supply or use level converters, which will allow it to work with both 5V and 3.3V devices.

Memory

The ATmega2560 microcontroller has 256 KB of flash program memory (of which 8 KB is used by the bootloader), 8 KB of SRAM and 4 KB of EEPROM (which is used to work with this memory).

Inputs and outputs

Using the , digitalWrite() and digitalRead() functions, each of the Arduino Mega's 54 digital pins can be configured to act as an input or output. The voltage level at the outputs is limited to 5V. The maximum current that a single output can supply or consume is 40 mA. All pins are paired with internal pull-up resistors (disabled by default) of 20-50 kΩ. In addition, some Arduino outputs can perform additional functions:

Serial interface Serial: pins 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). These pins are used to receive (RX) and transmit (TX) data over the serial interface. Pins 0 and 1 are also connected to the corresponding pins of the ATmega16U2 chip, which acts as a USB-UART converter.

PWM: pins 2 - 13 and 44 - 46. The function can output 8-bit analog values as a PWM signal.

SPI interface: pins 50 (MISO), 51 (MOSI), 52 (SCK), 53 (SS). When used, these pins allow communication over the SPI interface. The SPI lines are also routed to an ICSP header compatible with Arduino Uno, Duemilanove and Diecimila.

LED: 13. Built-in LED connected to pin 13. Sending a HIGH value turns the LED on, sending LOW turns it off.

TWI: pins 20 (SDA) and 21 (SCL). When used, these pins allow communication via the TWI interface. Note that the layout of these pins is different on the Arduino Duemilanove and Diecimila.

The Arduino Mega 2560 has 16 analog inputs, each of which can represent an analog voltage as a 10-bit number (1024 different values). By default, the voltage measurement is relative to the 0 to 5V range. However, the upper limit of this range can be changed using the AREF pin and the analogReference() function.

In addition to those listed on the board, there are several more conclusions:

AREF. Reference voltage for analog inputs. Can be used with the function.

reset. Formation of a low level (LOW) on this pin will reset the microcontroller. Typically, this pin is used to operate the reset button on expansion boards.

Connection

The Arduino Mega 2560 provides a number of options for communicating with a computer, another Arduino, or other microcontrollers. The ATmega2560 has four hardware UART transceivers for implementing serial interfaces (with TTL 5V logic level). The ATmega16U2 microcontroller (or ATmega8U2 on R1 and R2 boards) connects one of the transceivers to the computer's USB port, and when connected to a PC, it allows Arduino to be defined as a virtual COM port (for this, the Windows operating system will need the corresponding .inf file, in unlike OSX and Linux, where the board is recognized as a COM port automatically). The Arduino software package includes a special SerialMonitor program that allows you to read and send simple text data to the Arduino. When data is being transferred via the ATmega8U2/ATmega16U2 chip during a USB connection to a computer, the RX and TX LEDs on the board will blink. (Serial communication via pins 0 and 1, without using a USB converter, will not light these LEDs.)

Programming

The Arduino Mega is programmed using the Arduino software (download). See the ATmega2560 in the Arduino Mega for more information. It comes with a flashed bootloader that allows you to upload new programs to the microcontroller without the need for an external programmer. Interaction with it is carried out according to the original protocol STK500 ( , ).

The firmware source code for the ATmega16U2 microcontroller (or ATmega8U2 on R1 and R2 boards) is located in the Arduino repositories. The ATmega16U2/8U2 firmware includes a DFU (Device Firmware Update) bootloader that allows you to update the microcontroller firmware. To activate DFU mode, you must:

On boards of version R1: close the jumper on the reverse side of the board (near the image of Italy), then reset 8U2.

Automatic (software) reset

To avoid having to press the reset button each time before downloading the program, the Arduino Mega 2560 is designed in such a way that it can be reset programmatically from a connected computer. One of the ATmega8U2's data flow control (DTR) pins is connected to the ATmega2560's RESET pin via a 100nF capacitor. When the DTR line goes zero, the RESET pin also goes low for a period long enough to reset the microcontroller. This feature is used in order to be able to flash the microcontroller with just one click in the Arduino programming environment. This architecture allows you to reduce the bootloader timeout, since the flashing process is always synchronized with the signal decay on the DTR line.

However, this system can lead to other consequences. When connecting the Mega 2560 to computers running Mac OS X or Linux, its microcontroller will reset each time the software connects to the board. After a reset, the Arduino Mega2560 activates the bootloader for about half a second. Even though the bootloader is programmed to ignore extraneous data (i.e., all data that is not related to the process of flashing a new program), it can intercept the first few bytes of data from the packet sent to the board immediately after the connection is established. Accordingly, if the program running on the Arduino is intended to receive any settings or other data from the computer at the first start, make sure that the software that the Arduino interacts with sends a second after the connection is established.

There is a track on the Mega 2560 board (labeled as "RESET-EN"), by opening which, you can disable the automatic reset of the microcontroller. To restore the automatic reset function again, it is necessary to solder together the leads located along the edges of this track. Auto reset can also be disabled by connecting a 110 ohm resistor between the RESET pin and 5V.

USB overload protection

The Arduino Mega 2560 has resettable fuses that protect the computer's USB port from short circuits and overloads. Although most computers have their own protection, these fuses provide an additional layer of protection. If more than 500 mA is drawn from the USB port, the fuse will automatically disconnect the connection until the cause of the short circuit or overload is corrected.

Physical Specifications and Compatibility with Expansion Cards

The maximum length and width of the Mega2560 PCB is 10.2 cm and 5.4 cm respectively, including the USB connector and power connector protruding from the board. Three mounting holes allow you to attach the board to a surface or chassis. Note that the distance between digital pins 7 and 8 is not a multiple of the traditional 2.54mm and is 4mm.

The Arduino Mega2560 is designed to be compatible with most Arduino Uno, Diecimila and Duemilanove expansion boards. To do this, digital pins 0 - 13 (as well as the adjacent AREF and GND pins), analog inputs 0 - 5, the power connector and the ICSP connector are located the same on all boards. In addition, in these devices, the main UART transceiver lines are connected to the same pins (0 and 1) as the external interrupt lines 0 and 1 (pins 2 and 3, respectively). The SPI interface lines are routed to the ICSP connector on both boards - both on the Mega2560 and on the Duemilanove / Diecimila. Keep in mind that on the Arduino Mega, the I2C interface pin layout is different from the Duemilanove / Diecimila boards: on the Arduino Mega, these are pins 20 and 21, and on the Duemilanove / Diecimila, analog inputs 4 and 5.

If you make an Arduino yourself, and you don’t have an in-circuit programmer or other Arduino board other than the Arduino Mega 2560 to program the microcontroller, then you can use it to flash the chip without any problems.

What will be required:

Arduino Mega
Board with ATmega microcontroller to be flashed
Capacitor 100nF
USB cable connecting Arduino Mega to computer
Arduino IDE development environment
A few wires to connect the Arduino Mega with a homemade Arduino

The main difficulty is that the Arduino Mega has a different pinout than the Arduino UNO, Duemilanove or Diecimila, so the instructions for using the listed boards as a programmer are not suitable. You can learn more about the Arduino Mega pinout.

You need to connect Arduino Mega 2560 to board with Atmega 168/328 chip like this:

So the first thing you need to do is upload the ArduinoISP sketch. Open the Arduino IDE, select Tools - Board - Arduino Mega 2560 (Service - Board - Arduino Mega 2560). Select the correct COM port: Tools - Serial port - the desired port (Service - Serial Port - the desired port). Now go to File - Examples - ArduinoISP (File - Examples - ArduinoISP). The ArduinoISP sketch will open in front of you. Click the Upload button and upload it to the Arduino Mega 2560.

After the sketch is fully loaded, connect a 100nF capacitor between the +5V supply line and the Arduino Mega's RESET pin to disable auto-reset. Otherwise, nothing will work.

Select Tools - Burn Bootloader - Arduino as ISP (Service - Programmer - Arduino as ISP). After downloading the code, you will be able to enjoy your homemade Arduino.

If you experience errors:

Check if the board is correct
If you get an error like avrdude: stk500_getsync(): not in sync: resp=0x00, then you didn't put a 100nF capacitor between the +5V supply line and the RESET pin on the Arduino Mega
If you have a different error, then look for the answer in Google
If you didn't find the answer in Google, then use the thematic forums about Arduino

If you get the error avrdude: stk500_getsync(): not in sync: resp=0x00 avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51 while programming your Arduino, then auto-reset (DTR) is out of order. That is, the Arduino IDE cannot reset the Arduino, and the code upload fails. To avoid this, you can:

Press the reset button on the Arduino, the code appears "Binary sketch size: xxxx bytes (of a xxxxxxx byte maximum)"
If that doesn't work, you can connect the USB cable to the computer, but not to the Arduino, and after "binary sketch..." appears, quickly plug the cable into the Arduino
If that doesn't work, you can hold down the reset button on the Arduino, hit Upload in the Arduino IDE, and release the button when "binary sketch size..." appears.
If this does not help, then you can press the reset button after the “binary sketch size ...” appears and hold it for 2-10 seconds
If this does not help, then you can re-download the bootloader
If this does not help, then you can take another Arduino board if you have one in stock.
If this does not help, then you can only ask on the forum

Translation

This board differs from other arduinos in a large number of inputs and outputs, increased memory and other characteristics, which we will discuss below. Arduino Mega is presented in several versions. They practically do not differ from each other. The differences between the Arduino Mega 2560 R3 and previous versions of the board are in the following details:

To convert the USB-UART interface, the ATmega16U2 microcontroller is used in the R3 version and ATmega8U2 in the R1 and R2 versions of the board.
Since version R2, a pull-up resistor for the HWB line has been added on the board. This makes the microcontroller firmware process easier and more convenient.
In version R3, a couple of pins were added for the I2C SDA and SCL serial interface.
The noise immunity of the reset circuit has also been improved.
Changed microcontroller to work with USB-UART interface from ATmega8U2 to ATmega16U2

As you can see, the changes did not affect performance. Therefore, further we will only talk about the latest version of this board.

Arduino Mega 2560 R3

Arduino Mega 2560 is equipped with an ATmega2560 microcontroller with a clock frequency of 16 MHz.

Characteristics of Arduino Mega 2560

Microcontroller: ATmega2560
Clock frequency: 16MHz
Operating voltage: 5V
Limit supply voltages: 5-20 V
Recommended supply voltage: 7-12V
Maximum current from one output: 40 mA
Digital inputs/outputs: 54
Digital I/O with PWM support: 15
Analog inputs: 16
Flash memory: 256 KB (8 of which are used by the bootloader)
SRAM: 8 KB
EEPROM: 4 KB

Powering the Arduino Mega 2560

This board can be powered in four different ways:

Through the USB port. You can power the arduino from a computer, powerbank, smartphone (if it supports OTG mode) or from an adapter plugged into a power outlet.
Through pin + 5V. This pin is not only an output, but also an input. Be careful! 5 volts must be applied to this pin. Otherwise, you can burn the microcontroller itself.
Through the power plug located on the board. You can use batteries, accumulators and a variety of power supplies. This plug is connected to the VIN pin. Voltage and precautions are described in the next paragraph.
Through the VIN pin. The current from this pin passes through the built-in voltage regulator. According to the manufacturer, you can apply from 5 to 20 volts. But it is not so. Since the stabilizer is not 100% efficient, when 5 volts is applied to the VIN pin, the voltage may not be enough to power the microcontroller, and the digital pins will not have 5 volts, but less. Also, do not work at maximum voltage. At 20 volts on the VIN pin, the voltage regulator will get very hot, up to failure. Therefore, it is recommended to use a voltage of 7 to 12 volts.

As already mentioned above, the board has 54 digital pins. They can be both input and output. The operating voltage of these pins is 5 V. Each of them has a pull-up resistor and a voltage below 5 volts applied to one of these pins will still be considered as 5 volts (logical one).

The analog pins are inputs and do not have pull-up resistors. They measure the voltage applied to them and return a value between 0 and 1024 when used with the function. These pins measure voltage with an accuracy of 0.005 V.

PWM Arduino Mega

If you look closely at the board, you can see a tilde (~) icon next to some of the digital pins. This icon means that this pin can be used as a PWM output. Some arduino boards do not have this icon because manufacturers do not always find a place for this symbol on the board. The Arduino Mega has 15 PWM pins, these are digital pins 2 to 13 and 44 to 46. To use PWM, the Arduino has a special function.

Other pins:

Serial: 0 (rx) and 1 (tx), Serial1: 19 (rx) 18 (tx), Serial2: 17 (rx) and 16 (tx), Serial3: 15 (rx) and 14 (tx) are used for data transmission via serial interface.
Pins 53 (SS), 51 (MOSI), 50 (MISO), 52 (SCK) are designed for SPI communication.
Also on pin 13 there is an LED built into the board.
20 (SDA) and 21 (SCL) can be used to communicate with other devices via the I2C bus. You can read more about this interface on Wikipedia. The Arduino IDE has a built-in "wire.h" library for easier I2C work.
External interrupts: pins 2 (interrupt 0), 3 (interrupt 1), 18 (interrupt 5), 19 (interrupt 4), 20 (interrupt 3), and 21 (interrupt 2). These pins can be used as interrupt sources for a variety of conditions: low, rising, falling, or changing. See the function for more information.
AREF. Reference voltage for analog inputs. Can be used by the function.
reset. Formation of a low level (LOW) on this pin will reset the microcontroller. Typically, this pin is used to operate the reset button on expansion boards.

physical characteristics

Arduino Mega has the following dimensions: length 102mm and width 54mm. Arduino Mega weighs about 45 grams. The board has 4 holes for the possibility of fixing it on the surface. The distance between the pins is 2.5 mm, except for pins 7 and 8. There are 4 mm between them.

circuit diagram

General information

The Arduino Mega 2560 is a device based on the ATmega2560 microcontroller (). It includes everything you need for convenient work with the microcontroller: 54 digital inputs / outputs (of which 15 can be used as PWM outputs), 16 analog inputs, 4 UARTs (hardware transceivers for implementing serial interfaces), a 16 MHz crystal resonator , USB connector, power connector, ICSP connector for in-circuit programming and reset button. To start working with the device, simply supply power from an AC/DC adapter or battery, or connect it to a computer via a USB cable. The Arduino Mega is compatible with most expansion boards designed for the Arduino Duemilanove and Diecimila.

The Mega 2560 is an updated version of the Arduino Mega.

On Mega 2560 board R2 versions a resistor is added to pull the HWB line of the 8U2 microcontroller to ground. Such a measure makes it possible to simplify the process of updating the firmware and switching the device to DFU mode.

Board changes R3 versions listed below:

Pinout 1.0: Added SDA and SCL pins (near the AREF pin), as well as two new pins located near the RESET pin. The first - IOREF - allows expansion boards to adapt to the operating voltage of the Arduino. This pin is provided for compatibility of expansion boards with both 5V Arduino based on AVR microcontrollers and 3.3V Arduino Due boards. The second pin is not connected to anything and is reserved for future use.
Improved noise immunity of the reset circuit.
Microcontroller ATmega16U2 replaced by 8U2.