A computer mouse uses rotating wheels and phototransistors(?) to detect mouse motion. I took a mouse apart to see if I could apply these components to a project I'm working on.

I think I can use the mouse LEDs and phototransistors but I don't know how to select resistors (and other components?) to set the bias on an LED or phototransistor.

The mouse phototransistors and LED's don't have any identifying numbers written on them so I don't know what type they are. I hope they are somewhat standard but I don't know for sure. I don't have a strong electronics background. But I am somewhat knowledgeable.

I wonder if there's someone out there who can help me select bias resistors to avoid toasting the LED and phototransistor while providing enough power to get them to work. I have a 5-volt source of power.

I want to extract just the pulse output from from one transistor. There are actually two phototransistors in each physical component. I will send these pulses to my data acquisition (DAQ) unit that has a pulse counter input. I want to take the pulses from a phototransistor and feed them to the DAQ. The DAQ has optical isolation on its inputs.

I plan to disconnect the mouse sensors from the rest of the circuit. The mouse microprocessor circuit will not be used.

Here is a link I found showing where someone has done something similar to what I want. But they are using the microprocessor output instead the output of the phototransistor itself. The link shows the mouse circuits involved.

Thanks