Light dependent resistors

In this example, we will have a closer look at an LDR. The principal behind it is the same as the bend sensor used in previous bend sensor example. Depending on the light levels cast onto the sensor, the sensor changes its output voltage. LDR comes in different shapes and sizes and the LDR used in Figure 2.8 comes premounted with a surface mounted resistor on a small PCB manufactured by Adafruit. The principal of the PCB is similar to the circuit created using a breadboard and components in Figure 2.3.

Figure 2.8: A PCB mounted LDR and resistor

The difference is that in the case of the PCB, in this example, everything is mounted nicely and we only need to attach it to the FLORA board using alligator clips. As shown in Figure 2.8, the LDR PCB has three connections VCC, OUT, and GND. Sometimes VCC is used to indicate power in. OUT in this case is the output signal, which is an analog signal. In Figure 2.9, you will find the necessary connections to the FLORA board....