Adafruit Metro Mini 328 - 5V 16MHz<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>ATmega328 brains - This popular chip has 32KB of flash (1/2 K is reserved for the bootloader)， 2KB of RAM， clocked at 16MHz</li><li>Power the METRO Mini with 6-16V polarity protected on the Vin pin， or plug the micro USB connector to any 5V USB source.</li><li>20 GPIO pins， 6 of which are Analog in as well， and 2 of which are reserved for the USB-serial converter. There's also 6 PWMs available on 3 timers (1 x 16-bit， 2 x 8-bit). There's a hardware SPI port， hardware I2C port and hardware UART to USB.</li><li>GPIO Logic level is 5V but by cutting and soldering closed a jumper on the bottom， you can easily convert it to 3.3V logic</li><li>USB to Serial converter， there's a genuine FTDI hardware USB to Serial converter that can be used by any computer to listen/send data to the METRO， and can also be used to launch and update code via the bootloader</li></ul></div><img src="http://ecx.images-amazon.com/images/I/41MeH67%2Bi4L.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/51Cu0ZGEjYL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/61rAH6G%2BNyL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/51JTa-oao4L.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/61i0KzHhXuL.jpg" noproxy>