Wiring up a vtp8651 h photodiode

Hello I was wondering if someone could help me wire up a vtp8651 h photodiode. I have tried using several resistor values and changing the orientation but I can't get it to read different values when I shine a laser pointer on it. Here is the data sheet for the photodiode. http://www.perkinelmer.co.uk/CMSResources/Images/44-3712DTS_vtp8651.pdf Here is my schematic, the white led is the photodiode and the grey is the laser pointer.

Have you tried with the photodiode reverse-biased [that's anode to Ground, cathode to input/pull-up resistor]? Also, try digitalRead with that, too (finding the linear region may not be easy.)

thanks for the input but I'm still getting nothing. I changed from using a analog read to digital read but the values from the serial print don't seem to change at all. Switching the photodiode the other way didn't help either. It just read a really high number like an open circuit.

In the interest of full disclosure, please "post your code". A good quality picture of your set-up would also be helpful.

sorry about that here is my code

// this sketch displays changes in the photodiode. void setup() { Serial.begin(9600); }

void loop(){ Serial.println(analogRead(0)); }

here is a picture of how I wired up everything: red wire is 5v green wires are ground yellow wire is A0 gold-ish wires go to the laser the resistor is 10k the black square is the photodiode

a couple more pictures

Oh my.

You have:

void loop()

No Dice.

The result of the analogRead gets put into a variable, so to a digitalRead for that matter, and that variable gets Serial.print 'ed.

So, before your void setup (), place

int diodeVal = 0;


void loop()
  diodeVal = analogRead(0);
  Serial.println (diodeVal);

And… I’m assuming the photodiode leads make good contact in the breadboard.

Okay I got it working. Thanks runaway pancake for all of your help. In case anyone is interested in how to get the photodiode to work use runaway pancake's code and remove the resistor. For some reason this diode don't need any power coming in to function. Only the ground and the pin that is reading the values. Here is a picture of the setup that worked for me. green is ground yellow is A0 note: the pin on the photodiode that's red goes to the ground