Sep. 12 In-class exercise-Johnny, Qiao, Sujay

Arduino Light Sensitive Bar Graph

Team: Johnny Wu, Sujay Kotwal, Qiao Yin

The project uses Light Dependent Resistor or a photocell as the input sensor. The internal resistance of LDR decreases as the intensity of incident light increases. The LDR is connected in a voltage divider circuit with a 10K ohms resistor. Arduino measures the voltage across the LDR at the analog input pins. The input voltage is mapped by arduino and depending on the intensity of light, the mapped and quantized input signal is used to drive the 3 LEDs connected at the digital output pins of arduino. The 3 LEDs give a visual representation of intensity of incident light.

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