Arduino UNO R3 Compatible Board – ATmega328P 16AU, CH340G USB-Serial

The UNO-R3-CH340G is a microcontroller development board that is functionally compatible with the Arduino UNO R3, built around the Microchip ATmega328P microcontroller in the 16AU (TQFP) surface-mount package. The ATmega328P is an 8-bit AVR RISC-based MCU running at 16MHz, with 32KB of Flash memory (0.5KB reserved for the bootloader), 2KB of SRAM, and 1KB of EEPROM. The board exposes 14 digital input/output pins (6 of which support PWM output) and 6 analog input channels with a 10-bit ADC, making it suitable for a very wide range of electronics projects, from simple LED control to sensor interfacing and motor control.

A key difference between this board and an original Arduino UNO R3 is the USB-to-serial converter: instead of the ATmega16U2, this board uses the WCH CH340G chip, a widely adopted and cost-effective USB-to-UART bridge that supports USB 2.0 full-speed and baud rates from 50bps to 2Mbps. The CH340G requires the CH340 driver to be installed on the host computer—this is a standard step for CH340-based Arduino-compatible boards and is supported on Windows, macOS, and Linux. The board connects to the computer via a Micro USB port and can be powered either from USB (5V) or from an external source of 7–9V via the power jack or VIN pin.

The board includes a 16MHz crystal oscillator, a reset button, TX/RX and power indicator LEDs, a 3.3V regulator capable of supplying up to 50mA to external devices, and a DC input current limit of 40mA per I/O pin. It measures approximately 68.6mm × 53.4mm × 12.5mm and weighs about 27g without a cable. The board is fully compatible with the Arduino IDE, all standard Arduino shields, and the vast ecosystem of Arduino libraries and tutorials, making it a practical and economical choice for education, prototyping, and production development. A critical safety note: the maximum recommended input voltage for this non-original board is 9V; applying 12V (despite what some datasheets may suggest) can permanently damage the board.