At one end is an LED and at the other the LDR, and when attached to a glove it provides a finger sensor without the fuss ... a voltage can be read by an Arduino. You can see it in action in ...

In the microcontroller era today, Arduino is ... Here an LDR (Light Dependent Resistor) is used to measure the light level. The alarm system is triggered when a “Logic High (H)” level signal is ...