In the microcontroller era today, Arduino ... light level is below a threshold value. Here an LDR (Light Dependent Resistor) is used to measure the light level. The alarm system is triggered when a ...

Furthermore, the vacant solder pads near the three-pin interface header is for mounting a light-dependent resistor (LDR/CdS cell ... motion detector safety light circuits because the PIR sensor module ...

In order to accomplish this, [Bas] is using a light-dependent resistor and a pull-up resistor to create a resistance bridge, which is then connected to an analog input pin on a Raspberry Pi Pico.