Ohh damn! I should not lie to you! But my knowledge about arduino programming is really not much,
I haven't learnt the basics good enough yet, all the statements, symbols and so on,
I've really tried learning, and barely started to understand, but it was like 2 years ago, everything I've learnt is pretty much gone..
the sensor should give out a pwm signal? Between AO/DO and Gnd?
There is a schematic erlier in the thread on the sensor board, and also some pictures on the sensor unit itself, imgur link,