When you buy an Arduino Mega, the question of pinout will surely arise in the course of your electronics project.
Inputs and outputs of the Arduino Mega
Each of the 54 digital pins on the Arduino 2560 Mega can be used as an input or output, using the pinMode (), digitalWrite () and digitalRead () functions. They work with 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pullup resistor (disconnected by default) of 20-50 kOhms.
In addition, some pins have special 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 serial USB-to-TTL 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. For more information refer to the function attachInterrupt ()
PW
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 in the ICSP header, which is physically compatible with Uno, Duemilanove, and Diecimila.
LED:
13. there is a built-in LED connected to digital pin 13. When the pin is HIGH the LED is on, when the pin is LOW it is off.
TWI:
20 (SDA) and 21 (SCL). Support for 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 provides 10 bits of resolution (i.e. 1024 different values). By default, they measure ground to 5 volts. However, it is possible to change the upper end of their range using the AREF pin and the analogReference () function.
There are a few other pins on the board:
AREF:
Reference voltage for the analog inputs. Used with analogReference ().
Reset:
Bring this line to LOW to reset the microcontroller. Usually used to add a reset button for shields that block the one on the board.
Arduino Mega 2560 PIN Diagram
Arduino Mega Pin Mapping Table
| Pin Number | Pin Name | Mapped Pin Name |
|---|---|---|
| 1 | PG5 ( OC0B ) | Digital pin 4 (PWM) |
| 2 | PE0 ( RXD0/PCINT8 ) | Digital pin 0 (RX0) |
| 3 | PE1 ( TXD0 ) | Digital pin 1 (TX0) |
| 4 | PE2 ( XCK0/AIN0 ) | |
| 5 | PE3 ( OC3A/AIN1 ) | Digital pin 5 (PWM) |
| 6 | PE4 ( OC3B/INT4 ) | Digital pin 2 (PWM) |
| 7 | PE5 ( OC3C/INT5 ) | Digital pin 3 (PWM) |
| 8 | PE6 ( T3/INT6 ) | |
| 9 | PE7 ( CLKO/ICP3/INT7 ) | |
| 10 | VCC | VCC |
| 11 | GND | GND |
| 12 | PH0 ( RXD2 ) | Digital pin 17 (RX2) |
| 13 | PH1 ( TXD2 ) | Digital pin 16 (TX2) |
| 14 | PH2 ( XCK2 ) | |
| 15 | PH3 ( OC4A ) | Digital pin 6 (PWM) |
| 16 | PH4 ( OC4B ) | Digital pin 7 (PWM) |
| 17 | PH5 ( OC4C ) | Digital pin 8 (PWM) |
| 18 | PH6 ( OC2B ) | Digital pin 9 (PWM) |
| 19 | PB0 ( SS/PCINT0 ) | Digital pin 53 (SS) |
| 20 | PB1 ( SCK/PCINT1 ) | Digital pin 52 (SCK) |
| 21 | PB2 ( MOSI/PCINT2 ) | Digital pin 51 (MOSI) |
| 22 | PB3 ( MISO/PCINT3 ) | Digital pin 50 (MISO) |
| 23 | PB4 ( OC2A/PCINT4 ) | Digital pin 10 (PWM) |
| 24 | PB5 ( OC1A/PCINT5 ) | Digital pin 11 (PWM) |
| 25 | PB6 ( OC1B/PCINT6 ) | Digital pin 12 (PWM) |
| 26 | PB7 ( OC0A/OC1C/PCINT7 ) | Digital pin 13 (PWM) |
| 27 | PH7 ( T4 ) | |
| 28 | PG3 ( TOSC2 ) | |
| 29 | PG4 ( TOSC1 ) | |
| 30 | RESET | RESET |
| 31 | VCC | VCC |
| 32 | GND | GND |
| 33 | XTAL2 | XTAL2 |
| 34 | XTAL1 | XTAL1 |
| 35 | PL0 ( ICP4 ) | Digital pin 49 |
| 36 | PL1 ( ICP5 ) | Digital pin 48 |
| 37 | PL2 ( T5 ) | Digital pin 47 |
| 38 | PL3 ( OC5A ) | Digital pin 46 (PWM) |
| 39 | PL4 ( OC5B ) | Digital pin 45 (PWM) |
| 40 | PL5 ( OC5C ) | Digital pin 44 (PWM) |
| 41 | PL6 | Digital pin 43 |
| 42 | PL7 | Digital pin 42 |
| 43 | PD0 ( SCL/INT0 ) | Digital pin 21 (SCL) |
| 44 | PD1 ( SDA/INT1 ) | Digital pin 20 (SDA) |
| 45 | PD2 ( RXDI/INT2 ) | Digital pin 19 (RX1) |
| 46 | PD3 ( TXD1/INT3 ) | Digital pin 18 (TX1) |
| 47 | PD4 ( ICP1 ) | |
| 48 | PD5 ( XCK1 ) | |
| 49 | PD6 ( T1 ) | |
| 50 | PD7 ( T0 ) | Digital pin 38 |
| 51 | PG0 ( WR ) | Digital pin 41 |
| 52 | PG1 ( RD ) | Digital pin 40 |
| 53 | PC0 ( A8 ) | Digital pin 37 |
| 54 | PC1 ( A9 ) | Digital pin 36 |
| 55 | PC2 ( A10 ) | Digital pin 35 |
| 56 | PC3 ( A11 ) | Digital pin 34 |
| 57 | PC4 ( A12 ) | Digital pin 33 |
| 58 | PC5 ( A13 ) | Digital pin 32 |
| 59 | PC6 ( A14 ) | Digital pin 31 |
| 60 | PC7 ( A15 ) | Digital pin 30 |
| 61 | VCC | VCC |
| 62 | GND | GND |
| 63 | PJ0 ( RXD3/PCINT9 ) | Digital pin 15 (RX3) |
| 64 | PJ1 ( TXD3/PCINT10 ) | Digital pin 14 (TX3) |
| 65 | PJ2 ( XCK3/PCINT11 ) | |
| 66 | PJ3 ( PCINT12 ) | |
| 67 | PJ4 ( PCINT13 ) | |
| 68 | PJ5 ( PCINT14 ) | |
| 69 | PJ6 ( PCINT 15 ) | |
| 70 | PG2 ( ALE ) | Digital pin 39 |
| 71 | PA7 ( AD7 ) | Digital pin 29 |
| 72 | PA6 ( AD6 ) | Digital pin 28 |
| 73 | PA5 ( AD5 ) | Digital pin 27 |
| 74 | PA4 ( AD4 ) | Digital pin 26 |
| 75 | PA3 ( AD3 ) | Digital pin 25 |
| 76 | PA2 ( AD2 ) | Digital pin 24 |
| 77 | PA1 ( AD1 ) | Digital pin 23 |
| 78 | PA0 ( AD0 ) | Digital pin 22 |
| 79 | PJ7 | |
| 80 | VCC | VCC |
| 81 | GND | GND |
| 82 | PK7 ( ADC15/PCINT23 ) | Analog pin 15 |
| 83 | PK6 ( ADC14/PCINT22 ) | Analog pin 14 |
| 84 | PK5 ( ADC13/PCINT21 ) | Analog pin 13 |
| 85 | PK4 ( ADC12/PCINT20 ) | Analog pin 12 |
| 86 | PK3 ( ADC11/PCINT19 ) | Analog pin 11 |
| 87 | PK2 ( ADC10/PCINT18 ) | Analog pin 10 |
| 88 | PK1 ( ADC9/PCINT17 ) | Analog pin 9 |
| 89 | PK0 ( ADC8/PCINT16 ) | Analog pin 8 |
| 90 | PF7 ( ADC7 ) | Analog pin 7 |
| 91 | PF6 ( ADC6 ) | Analog pin 6 |
| 92 | PF5 ( ADC5/TMS ) | Analog pin 5 |
| 93 | PF4 ( ADC4/TMK ) | Analog pin 4 |
| 94 | PF3 ( ADC3 ) | Analog pin 3 |
| 95 | PF2 ( ADC2 ) | Analog pin 2 |
| 96 | PF1 ( ADC1 ) | Analog pin 1 |
| 97 | PF0 ( ADC0 ) | Analog pin 0 |
| 98 | AREF | Analog Reference |
| 99 | GND | GND |
| 100 | AVCC | VCC |
