Hi everyone, I have an adxl193 analog accelerometer (http://www.sparkfun.com/products/9332) that I am trying to interface with a phidget i/o board (http://www.phidgets.com/documentation/Phidgets/1011_0_Product_Manual.pdf). I am having trouble calibrating the signal because the acceleration is (zero-g_reference_signal - signal)/sensitivity and the zero-g reference signal is VCC/2. However, VCC is not constant - I assume since it is powered by USB. I would like to now use an external 5v power supply. I can see the signal on the oscilloscope when I connect the power supply. Unfortunately, the phidget is not detecting the sensor. I am completely wiring ignorant --- VCC and GND on the accelerometer are connected to +5v and grn on the power supply while OUT on the accelerometer is connected only to A1 on the phidget ----- VCC and GND on the phidget are not connected to anything. Does anyone have any advice? I am electronics ignorant. Thank you.