MEGA2560 R3 — ATmega2560 Development Board with CH340 & USB Type-C
When the Uno runs out of pins or program space, the MEGA2560 R3 is the answer. With 54 digital I/O pins, 16 analog inputs, 4 hardware serial ports, and 256 KB of flash memory, this is the go-to board for 3D printers, CNC controllers, large sensor arrays, and complex robotics projects. This improved version uses the CH340G USB-to-serial chip and a modern USB Type-C connector — fully compatible with the Arduino IDE out of the box.
- 54 Digital I/O (15 PWM)
- 16 Analog Inputs
- 4 Hardware Serial Ports
- 256 KB Flash / 8 KB SRAM
- CH340G USB-to-Serial
- USB Type-C Connector
- Arduino IDE Compatible
- 5V Operating Voltage
- ICSP Header Included
- Mega Shield Compatible
The CH340G USB chip is cost-effective and reliable on macOS and Linux with no drivers needed. Windows 10 and 11 users may need to install the CH340 driver once. Search "CH340 driver WCH" for the official download from the chip manufacturer.
This improved R3 version upgrades to USB Type-C for programming and power — reversible and compatible with any standard Type-C cable. No adapter needed if you're already on Type-C.
Electrical & Physical Specifications
Full specifications for the MEGA2560 R3 CH340 TYPE-C development board. Based on the ATmega2560-16AU microcontroller running at 16 MHz with 5V operating voltage.
- Microcontroller
- ATmega2560 (8-bit AVR)
- USB Interface Chip
- CH340G (replaces ATmega16U2)
- USB Connector
- Type-C
- Operating Voltage
- 5V DC
- Input Voltage (Recommended)
- 7–12V
- Input Voltage (Limits)
- 6–20V
- Digital I/O Pins
- 54 (15 support PWM output)
- Analog Input Pins
- 16 (10-bit, 0–5V)
- Hardware Serial Ports (UART)
- 4 × TTL-level UART
- DC Current per I/O Pin
- 40 mA max
- DC Current for 3.3V Pin
- 50 mA max
- Flash Memory
- 256 KB (8 KB used by bootloader)
- SRAM
- 8 KB
- EEPROM
- 4 KB
- Clock Speed
- 16 MHz crystal oscillator
- Communication Interfaces
- SPI (ICSP header), I²C (SDA/SCL), 4× UART
- Board Dimensions
- 101.52 mm × 53.3 mm
- Shield Compatibility
- Arduino Mega 2560 R3 shields
- IDE Compatibility
- Arduino IDE (select "Arduino Mega or Mega 2560")
- Built-in LED
- D13 (user-programmable)
- ICSP Header
- Yes (AVR in-system programming)
- Reset Button
- Yes
Pinout & Getting Started
The MEGA2560 R3 exposes its pins across four headers around the board perimeter. Here is a summary of the key pin groups and how to get your first sketch running.
Digital I/O (D0–D53)
- D0–D1 Serial0 (RX/TX) — USB programming
- D2–D3 External interrupts INT4/INT5
- D13 Built-in LED (LED_BUILTIN)
- PWM pins D2–D13, D44–D46 (15 total)
- D18–D21 Serial1–3 (4 hardware UARTs)
Analog Inputs (A0–A15)
- A0–A15 10-bit analog inputs (0–5V)
- A4/A5 I²C SDA/SCL (shared with pins 20/21)
- Reference AREF pin for external voltage ref
Power Pins
- VIN External supply input (7–12V)
- 5V Regulated 5V output (from USB or VIN)
- 3.3V 3.3V regulated output (50 mA max)
- GND Multiple ground pins
- RESET Active-low reset
Communication
- Serial0 D0/D1 — USB via CH340G
- Serial1 D18/D19 (TX1/RX1)
- Serial2 D16/D17 (TX2/RX2)
- Serial3 D14/D15 (TX3/RX3)
- SPI ICSP header (MISO/MOSI/SCK/SS)
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1Install CH340 driver (Windows only)
macOS and Linux detect the board automatically. Windows 10/11 users should download the CH340 driver from WCH's website and install it before plugging in the board.
-
2Connect via USB Type-C
Use any standard USB-A to Type-C or Type-C to Type-C cable. The board powers up immediately and the green power LED will illuminate.
-
3Select the correct board in Arduino IDE
Go to
Tools > Board > Arduino AVR Boardsand selectArduino Mega or Mega 2560. Then selectATmega2560under Processor. -
4Select the correct port
Go to
Tools > Portand select the COM port that appeared when you plugged in the board. On Windows it will show as "USB-SERIAL CH340 (COMx)". -
5Upload the Blink example to verify
Open
File > Examples > 01.Basics > Blinkand click Upload. The D13 LED should blink once per second, confirming the board is working correctly.
Applications & Use Cases
The MEGA2560's combination of large flash memory, abundant I/O pins, and multiple hardware serial ports makes it the board of choice whenever an Uno's resources run short — from 3D printer control boards to large automation rigs.
Powers RAMPS 1.4 and similar shields for FDM 3D printers — the most common MEGA2560 application in the maker community.
Drive Grbl-compatible CNC shields for routers, laser cutters, and milling machines. Four serial ports handle multiple steppers comfortably.
Control multiple servos, motors, and sensors simultaneously. The 54 I/O pins and PWM outputs make complex robot builds straightforward.
Read dozens of sensors simultaneously using analog inputs and multiple UARTs — ideal for weather stations, environmental monitors, and data loggers.
Industrial-style automation projects that need many digital inputs/outputs, relay control, and serial communication to HMI panels.
The extra headroom in pins, memory, and serial ports makes the MEGA2560 ideal for classroom projects and advanced maker builds that outgrow the Uno.
If your sketch is running out of flash memory, you need more than 14 digital pins, you need more than one hardware serial port, or your project needs to talk to many peripherals simultaneously — the MEGA2560 is the natural next step within the Arduino ecosystem.
Frequently Asked Questions