Arduino Uno R3

The Uno R3 is a open source microcontroller board based on the ATmega328 chip. 

This Board has 14 digital input/output pins, 6 analog input pins, Onboard 16 MHz ceramic resonator, 

Port for USB connection, Onboard DC power jack, An ICSP header and a microcontroller reset button. 

It contains everything needed to support the microcontroller. Using the board is also very easy, 

simply connect it to a computer with a USB cable or power it with DC adapter or battery to get started.

The Uno R3 CH340G ATmega328p Development Board is the low-cost version of the popular Uno R3 Arduino. 

It is assembled in India with the CH340 USB to Serial converter chip, instead of using an Atmega16U2 chip.

It works 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 CH340 chip.

External (non-USB) power can come either from an AC-to-DC adapter (wall-wart) or battery. 

The adapter can be connected by plugging a 2.1mm center-positive plug into the board's power jack. 

Also leads from a battery can be inserted in the Gnd and Vin pin headers of the Power connector. 

The board can operate on an external supply of 7 to 30V volts. If supplied with less than 7V, however, 

the 5V pin may supply less than five volts and the board may be unstable. 

the voltage regulator may overheat and damage the board. The recommended range is 5v to 24V for Uno.