Directional Light Sensor

Specifications

Ability to quantify light intensity in particular direction is one of the most important capability you can give to your robot. This sensor is essentially a photo transistor with precision lense assembly. It receives light from the cone of +- 10 degrees only. This is a NPN photo transistor. All you have to do is connect resistor between collector and Vcc for biasing and measure voltage across collector and ground. Resistance can be varied between 10K to 100K ohm. More resistance gives better sensitivity to the light.