The Uno R3 CH340G ATmega328p Development Board is the low-cost version of the popular Uno R3 Arduino. It is assembled with the CH340 USB to Serial converter chip, instead of using an Atmega16U2 chip. We have used plenty of these low-cost Arduino boards with CH340 chips, and have found them to work perfectly. The only time the CH340 chip is used is during programming and when using the serial output of the USB port. During normal operation, this board is identical to the more expensive version without the CH340 chip. Specification: Microcontroller Chip  ATmega328 (SMD) Operating Voltage 5V Input Voltage (recommended) 7-12V Input Voltage (limit) 6-20V Digital I/O Pins 14 (of which 6 provide PWM output) PWM Digital I/O Pins 6 Analog Input Pins 6 Clock Speed 16 MHz. SRAM 2 KB (ATmega328) EEPROM 1 KB (ATmega328P) Operating Temperature (°C) -40 to 90 Power Supply via DC Jack or USB