Light Tracking Servo System Using Cadmium Sulfide Light

Light Tracking Servo System Using Cadmium Sulfide Light Dependent Resistors Brandon Agtarap and Branden Nakahara

Introduction • Arduino Based Light Tracking System o Tracks for the maximum intensity of light o When there is a decrease in intensity of light, it automatically changes its direction towards the brightest source o Uses Cadmium Sulfide light dependent resistors • Arduino Based Lux Meter o Luminosity sensor using an advanced digital light sensor • Lux is the SI unit of illuminance and luminous emittance • Applications o Will be used to develop a light tracking system model that follow the movement of light o May replace the Cd. S resistors with a solar panel that can be used for a sun tracking system

Specs • DAC: o Resolution: • (5 V) / (210) = 5. 0 m. V o 6 Analog inputs o Pins 9 & 10 provide 8 -bit PWM output • Cd. S LDRs: o Spectrum Peak Value: 540 nm (yellow-green light) o At ambient room light: • 20 ms rise time and 30 ms fall time o g = log(R 10/R 100) • ADC: o Approximates Human Eye Response – filters out the 50 -60 Hz lighting ripple o 100 k. Hz or 400 k. Hz o 0. 1 to 40, 000 Lux range • 1 Lux = 1. 46 e-7 watts/cm 2 ~ full moon on a clear night

Block Diagram

Circuit

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Schedule Tuesday Wednesday • Design Review • Testing of model using different light sources • Data collection from lux meter Thursday Friday • Final Testing • Final • Change Presentations variables of circuit to find a more ideal system