The RFD22121 USB Programming shield interface will be needed to load the arduino code/sketches onto the RFduino modules, see RFD22301 RFduino SMT module 8011689 and RFD22102 RFduino DIP 8011691. The RF Digital RFD22121 USB shield and the RFD22124 PCB USB shield will plug into any USB port. The RFduino can be mounted on top or below it and the shields can plug into a breadboard.
The RFD22124 (8011702) includes a PCB type connector not a formed metal USB connector like the RFD22121 model incorporates.
Dimensions: L 38.45mm x W 22.86mm On board FTDI chip enable it to be used as a UART Serial Interface - RX, TX, RESET USB Controller: FT231XQ-R Interface IC
