This is a USB programmer which enables you to upload new firmware for the ARPIE. This programmer can also be used with other “bare bones Arduino” projects or as a general USB-to-TTL serial interface.
It is based on the Silicon Labs CP2102 chip, plugs directly into a USB socket and comes with a 4-way cable of 20mm length.
The board breaks out GND, VCC(+5V and +3.3V), TXD, RXD and RST.
Please note that the RST pin will not drive the reset line of an AVR in the same way that an FTDI-type cable will. A manual reset is still needed to start an upload.
You will need to download free drivers from Silicon Labs web site http://www.silabs.com/products/mcu/Pages/USBtoUARTBridgeVCPDrivers.aspx
Windows and Mac are supported by the SiLabs drivers. Please check the link to validate support for your operating system version