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

2. 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 CdS resistors with a solar panel that can be used for a sun tracking system

3. Specs DAC: o Resolution: (5 V) / (2 10 ) = 5.0 mV o 6 Analog inputs o Pins 9 & 10 provide 8-bit PWM output CdS 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  = log(R10/R100) ADC: o Approximates Human Eye Response – filters out the 50-60 Hz lighting ripple o 100 kHz or 400 kHz o 0.1 to 40,000 Lux range 1 Lux = 1.46e -7 watts / cm 2 ~ full moon on a clear night

4. Block Diagram

5. Circuit

6. Circuit-continued

7. Schedule TuesdayWednesdayThursdayFriday Design Review Testing of model using different light sources Data collection from lux meter Final Testing Change variables of circuit to find a more ideal system Final Presentations