I built a simple sensor board connecting a RFDUINO to two I2C components. A ADXL345 accelerometer and a MPR121 Touch controller. The board also includes an RGB LED, vibration motor and Li-Po charger circuit.
The I2C bus seems not to be working, and I cannot read the register (using the wire library for Arduino) on the two I2C. If I connect a scope to the I2C lines (using some pads exposed on the PCB, see figure) I can see a 3.3v but no activity on both SCL and SDA lines.
In a ealier breadboard prototype I used a RFDUINO shield and breakout boards for ADXL345 and MPR121 and did not present any problems.