Arduino Compatible Mega 2560 R3 ATmega2560 CH340G Development Board

Arduino Compatible Mega 2560 R3 ATmega2560 CH340G Development Board is a high-I/O-density 8-bit AVR microcontroller development board built around the Microchip/Atmel ATmega2560-16AU MCU and WCH CH340G USB-to-serial interface. Furthermore, it provides a massive array of 54 digital I/O pins (15 PWM outputs), 16 analog 10-bit ADC inputs, 4 independent hardware UART serial ports, and 256KB of Flash memory. Consequently, it is the industry-standard control board for RAMPS 1.4 3D printers, multi-axis CNC routers, MobiFlight flight-simulator cockpits, and complex industrial automation panels that exceed the pin count of an Arduino UNO.

Key Features:

• Massive 54 Digital I/O & 16 Analog Inputs: Nearly quadruples the GPIO capacity of an Arduino UNO to drive dozens of stepper drivers, relays, limit switches, and sensors simultaneously.
• 256KB Flash & 8KB SRAM: Offers 8× the Flash memory and 4× the SRAM of the ATmega328P, easily hosting large firmware suites like Marlin 3D printer firmware or MobiFlight.
• 4 Hardware UART Serial Ports: Dedicated `Serial` (USB), `Serial1` (D18/D19), `Serial2` (D16/D17), and `Serial3` (D14/D15) allow simultaneous hardware communication with Nextion HMI displays, GPS receivers, ESP8266 Wi-Fi modules, and GSM modems.
• Reliable CH340G USB-to-UART Bridge: Connects via a robust full-size USB Type-B port with stable driver support across Windows, Linux, and macOS.
• backward-Compatible Shield Header Footprint: Left-side header rows match the standard Arduino UNO R3 layout while the right-side 36-pin dual-row header exposes Digital Pins 22–53.

Technical Specifications:

• Microcontroller: Microchip / Atmel ATmega2560-16AU (TQFP-100 Package, 8-Bit AVR @ 16 MHz)
• USB-to-Serial Converter: WCH CH340G
• Operating Logic Voltage: 5.0V DC
• Input Supply Voltage (DC Jack / VIN): 7.0V to 12.0V DC Recommended (6V–20V Limits)
• Digital I/O Pins: 54 Pins (D0–D53; 15 Pins Provide 8-Bit PWM Output: D2–D13 and D44–D46)
• Analog Input Pins: 16 Channels (A0–A15, 10-Bit SAR ADC)
• Hardware UARTs: 4 Serial Ports (`Serial0`, `Serial1`, `Serial2`, `Serial3`)
• Memory: 256 KB Flash (8 KB Used by Bootloader), 8 KB SRAM, 4 KB EEPROM
• External Interrupts: 6 Pins (`D2/INT0, D3/INT1, D21/INT2, D20/INT3, D19/INT4, D18/INT5`)

Mechanical Specifications:

• PCB Substrate: Extended Arduino Mega R3 Blue Double-Sided FR-4 Fiberglass PCB
• Connectors: Standard USB Type-B Female Port, 5.5mm × 2.1mm DC Barrel Jack, 6-Pin ICSP Header
• Mounting Holes: 6 × 3.2mm (M3) Mounting Holes

Dimensions:

• Length: 101.5 mm
• Width: 53.3 mm
• Height: 14.0 mm
• Weight: ≈ 37 g

Pinout and Wiring:

• 4 × Hardware UARTs: `RX0/TX0 (D0/D1)`, `TX1/RX1 (D18/D19)`, `TX2/RX2 (D16/D17)`, and `TX3/RX3 (D14/D15)`.
• I2C Bus: `D20 (SDA)` and `D21 (SCL)` (also mirrored on the top-left `SDA/SCL` R3 header pins).
• SPI Bus: `D50 (MISO), D51 (MOSI), D52 (SCK), D53 (SS)` plus the central 6-pin `ICSP` header.
• End-Row Digital Header (D22–D53): 2×18 female header along the right edge providing 32 digital I/O channels plus dual `5V` and `GND` pins.
• Engineering Precaution: Although each individual ATmega2560 GPIO pin can source up to 20mA, the total combined current across all I/O ports must not exceed 200mA; use external ULN2803 drivers, MOSFETs, or opto-isolated relay boards when switching heavy loads.

Datasheet Reference:

• View Official Microchip ATmega2560 8-Bit AVR Microcontroller Datasheet PDF

Commonly Used in:

• RepRap RAMPS 1.4 / 1.5 / 1.6 3D Printers and Multi-Axis CNC Controllers
• MobiFlight & SimVim Home Cockpit Flight Simulator Instrument Panels
• Large-Scale Model Railroad Signaling, Escape Room Puzzles, and Robotics

Applications:

• 3D Printer & CNC Motion Control: Stacks directly beneath a RAMPS 1.4 shield to drive 5× A4988/DRV8825 stepper motors, heated beds, extruders, and LCD controllers.
• Multi-Serial IoT Hub: Polls a Modbus RS485 network on `Serial1`, a GPS module on `Serial2`, and a Nextion touchscreen on `Serial3` without unstable `SoftwareSerial` bit-banging.
• High-Density Button & LED Matrix Control: Reads 40+ cockpit switches and rotary encoders in real time.

Equivalent Models:

• Mega 2560 PRO MINI (ATmega2560-16AU CH340G): Compact 55×38mm embeddable version of this exact ATmega2560 + CH340G circuit without bulky female shield headers.
• Arduino Due R3 (AT91SAM3X8E): 84MHz 32-bit ARM Cortex-M3 board in the identical Mega 2560 footprint (operates strictly at 3.3V logic).
• Arduino UNO R3 (ATmega328P): Smaller 14-digital / 6-analog board for compact projects that do not require 54 GPIOs or 4 UARTs.

Package Includes:

• 1 × Arduino Compatible Mega 2560 R3 ATmega2560 CH340G Development Board