To deal with this you’ll want to supply the Arduino 5V via the RAW pin (it’s regulator will then supply 3.3V to VCC feeding the Host Shield and Bluetooth module). Then route a wire from this ...

Based on a Nordic Semiconductor 32-bit ARM system-on-chip that has built-in support for Bluetooth 4.0, the RFduino runs the same code as Arduino UNO and DUE boards, and it works with any type of ...