CT-UNO is a Cytron version of Arduino Uno. This board combines the simplicity of the UNO’s Optiboot bootloader (which load program faster), the stability of the FTDI and the R3 shield compatibility of the latest “Arduino UNO R3”. CT-UNO has all the amazing features Arduino UNO offer. 14 Digital I/O pins with 6 PWM pins, 6 Analog inputs, UART, SPI, external interrupts, not to forget the I2C too. The SDA, SCL and IOREF pins which being broken out on UNO R3 are on CT-UNO too. We has also populated the ISP header pins (SPI and power). With this, CT-UNO will be compatible with all Arduino UNO's shield.