The Arduino Uno R3 is a microcontroller board based on the ATmega328P (datasheet) chip. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an ICSP header and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with an AC-to-DC adapter or battery to get started. You can tinker with your UNO without worrying too much about doing something wrong, worst case scenario you can replace the chip for about R35.00 and start over again.

You can download the software for free on the Arduino official website.

If I may be bold to ask – please donate when downloading the software, the Arduino guys do not make any money out of these clones (but 100% identical boards) we sell. You can donate as little as $3.00. Think of it this way – you can get all the Arduino software and upgrades for the rest of your life for only $3.00. Yes, you can get it free but your $3.00 make this a win-win thing for all.On the Arduino IDE download page is an option to donate Arduino – Donate.

Microcontroller	ATmega328P
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
DC Current per I/O Pin	20 mA
DC Current for 3.3V Pin	50 mA
Flash Memory	32 KB (ATmega328P) of which 0.5 KB used by bootloader
SRAM	2 KB (ATmega328P)
EEPROM	1 KB (ATmega328P)
Clock Speed	16 MHz
LED_BUILTIN	13
Length	68.6 mm
Width	53.4 mm
Weight	25 g