signal from PPG heart/pulse sensor

Hello everyone, i am completely new to the forum and to arduino. I am trying to get a signal from a PPG sensor without an op Amp. I have wired the sensor up in the same way as the Arduino Potentiometer sketch but so far have just had a random reading. The ultimate goal is to turn servos with the output data. Any tips or hints would be greatly appreciated. Many thanks.

This is the ARM/LPC forum!

Leon