Light Dependent Resistor (LDR) – 5mm

Teach your robots to distinguish between day and night. The 5mm Light Dependent Resistor (LDR), also known as a photoresistor, is an essential, highly responsive component for optical sensing. Manufactured using high-quality cadmium sulfide (CdS), this resistor exhibits photoconductivity—meaning its electrical resistance drops drastically when exposed to bright light and spikes exponentially into millions of ohms in complete darkness.

As an IIT Bhubaneswar-incubated STEM enterprise, XROBOTICS WORKS integrates this 5mm LDR into our foundational electronics and automation curricula. It is the core hardware component behind student-favorite projects like the Automatic Street Light Controller, Laser-Based Security Tripwires, and Dual-Axis Solar Trackers deployed across composite school labs. Operating as a simple analog component, it can be easily paired with a 10kΩ resistor to create a quick voltage divider circuit, allowing any Arduino, ESP32, or Raspberry Pi to read ambient light percentages with absolute ease. Cheap, reliable, and deeply educational, it is an absolute staple for any PM Shri Robotics Lab inventory.