Compared to the old version, R3 version major changes:
1) Atmega 16U2 chip alternative 8U2. Means a higher transfer rate and memory.
2) increase the SDA and SCL interface.
1. Stitching changes: beside the AREF sutural added two I2C pins (SDA and SCL, only Analog copy of 4 and 5, are not additional I2C interface), in addition, beside the RESET also added two pins, one is IOREF, can let the extension board to board, load voltage, the stitching is tell extension board currently on-board voltage is how many (such as UNO is 5 v, can is regarded as a copy of the power pins, does not provide a level), the other one is after treated with placeholder pins.
2. The RESET circuit is more stable. RESET button position is changed, and moved to near the USB interface of voids, it is more convenient.
3. ATmega16U2 instead of 8 u2, this does not mean that there are 16 k flash R3 can make your code run faster, the update service for the USB interface chip, it make UNO can simulate USB HID in theory, such as MIDI / Joystick / Keyboard.
Open circuit diagram of the original design, the development of software interface for free download, can also be in accordance with the requirements and their modified, download the program is simple and convenient. Can simply use sensors, all kinds of electronic components connection (such as: LED lights, buzzer, buttons, photoresistance, etc.), make all sorts of interesting work.Microprocessor controller (ATMEGA328), using high-speed development interface and the environment are very simple and easy to understand, very suitable for beginners to learn.
Digital I/O Digital inputs/outputs were：0~13.
Analog I/O Analog input/output: 0~5
Support ISP download function.
The input voltage: when connected to the computer USB without external power supply,
external power supply 7 v to 12 v dc input voltage.
Output voltage: 3.3 V and 5 V dc voltage output dc voltage output.
Using Atmel Atmega328 microprocessor controller.
What is the Arduino?
The Arduino is a Simple I/o platform based on open source code, and use Java, such as Processing/Wiring of C language development environment, the characteristics of easy to understand. Allows you to quickly use the Arduino do interesting things.
The Arduino can be used with some electronic components such as: LED lights, buzzer, buttons, photoresistance, etc. The Arduino development environment based on the principle of open source interface, allows you to free download to use developed more amazing interactive work.
1 X UNO R3 ATMEGA328P ATMEGA16U2 2014 New Version Board
1 X High quality USB cable