Mega 2560 R3 Compatible Board — ATmega2560 with CH340G USB Interface The Mega 2560 R3 CH340 is a high-performance, Arduino-compatible development board built around the ATmega2560 8-bit AVR microcontroller — Microchip's most I/O-rich AVR for the Arduino ecosystem. With 54 digital I/O pins, 16 analog inputs, 256 KB of flash memory, and 4 hardware serial ports, the Mega 2560 is the go-to platform when the standard Arduino UNO runs out of pins or memory. This board adopts the reliable CH340G USB-to-serial chip, ensuring plug-and-play compatibility on Windows 7, 8, 10, macOS, and Linux without hardware-level driver issues. The pin layout is fully compliant with the official Arduino Mega 2560 R3 standard, meaning all Mega-compatible shields, libraries, and sketches work out of the box. Whether you're building a 3D printer controller, a multi-axis CNC machine, a complex robotics platform, or a large-scale IoT sensor network, the Mega 2560 R3 CH340 gives you the headroom to scale without compromising performance. Technical Specifications Parameter Specification Main Microcontroller ATmega2560 (TQFP100) USB-to-Serial Chip CH340G Operating Voltage 5V USB Power Input 5V via USB Type-B (Square) External Power Input DC 7–12V (recommended 9V, barrel jack) Clock Speed 16 MHz Flash Memory 256 KB (8 KB used by bootloader) SRAM 8 KB EEPROM 4 KB Digital I/O Pins 54 (pins 2–13 and 44–46 support PWM) PWM Output Pins 15 Analog Input Pins 16 (A0–A15, 10-bit ADC) DC Current per I/O Pin 40 mA max 3.3V Output Current 50 mA max Hardware Serial Ports (UART) 4 (Serial, Serial1, Serial2, Serial3) I2C Interface 1 (pins 20 SDA / 21 SCL) SPI Interface 1 (pins 50 MISO / 51 MOSI / 52 SCK / 53 SS) ICSP Header Yes (in-circuit serial programming) Reset Button Yes Onboard LEDs Power LED, TX0/RX0 LEDs, D13 LED Included USB Cable 50 cm USB-A to USB-B cable OS Compatibility Windows 7 / 8 / 10 / 11, macOS, Linux For complete electrical characteristics and register-level documentation, refer to the official ATmega2560 Datasheet (Microchip Technology). For USB-to-serial driver specifications, see the CH340G Datasheet. Board Layout & Label Guide CH340G USB-to-Serial Chip — Converts USB to UART; compatible with Win7/8/10 and modern macOS/Linux natively ATmega2560 MCU — Main 8-bit AVR processor with 256 KB flash, 8 KB SRAM, running at 16 MHz 16 MHz Crystal Oscillator — Provides precise clock timing for the microcontroller USB Port (Type-B Square) — For programming, serial monitoring, and USB power input DC Power Jack (7–12V) — Barrel jack for standalone power supply; AMS1117 regulates to 5V AMS1117 Voltage Regulator — Onboard 5V linear regulator for powering the board from external DC Reset Button — Manually resets and restarts the running sketch Digital I/O Pins D0–D53 — 54 general-purpose digital pins; 15 support PWM output Analog Pins A0–A15 — 16 analog inputs; all also usable as digital I/O I2C Header (pins 20/21) — SDA on pin 20, SCL on pin 21; dedicated I2C communication interface SPI Header (pins 50–53) — MISO/MOSI/SCK/SS pins for high-speed SPI device communication 4× UART Headers — Serial (D0/D1), Serial1 (D18/D19), Serial2 (D16/D17), Serial3 (D14/D15) ICSP Header — 6-pin in-circuit serial programming connector for bootloader flashing Power Output Pins — 3.3V (50 mA max), 5V, GND, VIN for powering external modules TX0/RX0 LEDs — Blink during serial data activity on the primary UART D13 LED — Onboard indicator driven by digital pin 13; useful for debug feedback To connect Grove-standard sensor modules directly to the Mega 2560's pins, the Seeed Studio Grove Mega Shield v1.2 provides standardized 4-pin Grove connectors for digital (D0–D21) and analog (A0–A15) interfaces — making sensor wiring clean and mistake-proof. Application Scenarios 1. Getting Started — Multi-LED Blink with millis() The Mega's 54 digital I/O pins make it straightforward to drive multiple independent outputs simultaneously. This example blinks three LEDs at different intervals using millis() — a non-blocking technique essential for real embedded projects. // Non-blocking multi-LED blink using millis() // Connect: LEDs with 220Ω resistors on pins 13, 12, 11 unsigned long prevMillis1 = 0, prevMillis2 = 0, prevMillis3 = 0; const long interval1 = 500, interval2 = 1000, interval3 = 1500; bool state1 = LOW, state2 = LOW, state3 = LOW; void setup() { pinMode(11, OUTPUT); pinMode(12, OUTPUT); pinMode(13, OUTPUT); } void loop() { unsigned long now = millis(); if (now - prevMillis1 >= interval1) { prevMillis1 = now; state1 = !state1; digitalWrite(11, state1); } if (now - prevMillis2 >= interval2) { prevMillis2 = now; state2 = !state2; digitalWrite(12, state2); } if (now - prevMillis3 >= interval3) { prevMillis3 = now; state3 = !state3; digitalWrite(13, state3); } } 2. Multi-Channel Analog Data Acquisition The Mega 2560 provides 16 analog inputs (A0–A15), making it ideal for multi-sensor data acquisition systems. This example reads 4 sensors simultaneously and prints their values and converted voltages to the Serial Monitor. // Multi-channel analog read — read sensors on A0 to A3 // Connect: sensors or potentiometers to A0–A3 void setup() { Serial.begin(115200); } void loop() { for (int ch = 0; ch
