Digital I/O Pins: 14 (of which 6 provide PWM output)
Analog Input Pins: 6
DC Current per I/O Pin: 40 mA
DC Current for 3.3V Pin: 50 mA
Flash Memory: 32 KB (ATmega328) of which 0.5 KB used by bootloader
SRAM: 2 KB (ATmega328)
EEPROM: 1 KB (ATmega328)
Clock Speed: 16 MHz
The Arduino UNO R3 CH340 is a clone of the standard UNO R3, but has been modified to bypass the standard (and expensive) FTDI drivers with the CH340 USB serial chip. The Uno R3 ATmega328P’s drivers for the chip are available for either Windows or MacOS, depending on the operating system that you use. It not only makes prototyping and development more accessible to students and hobbyists, but it also encourages the open-source Maker movement.
In terms of upgrades since previous versions of the Arduino UNO, the Arduino UNO R3 CH340 not only offers a variety of major upgrades that improve the power and efficiency of the board, but also a few minor quality-of-life upgrades. These include the addition of solder pads from pins PB4 through PB7 to the USB header, ICSP header pins rather than simple solder pads, and a 10-pin connector for the I2C, AD4/SDA and AD5/SCL. These seemingly insignificant improvements have made the Arduino-compatible Uno R3 ATmega328P’s drivers and hardware much easier and simpler to utilize, making it an obvious upgrade from the original versions.