This tutorial gives an introduction to the HY-M154 / 817 optocoupler module. Moreover, a simple application is programmed that shows how to wire and how to program an Arduino when working with the module. Optocouplers are very useful when you need to isolate different sections of a circuit, for example in power. PC817 is an optoisolator consists of an infrared diode and phototransistor. In electric circuits, we use mostly filters to remove noise. The circuit based on the capacitor and resistor always removes the noise from the incoming signal but the value capacitor and resistor always depend on the. There are many different applications for optocoupler circuits, so there are many different design requirements, but a basic design for an optocoupler providing isolation for example between two circuits, simply involves the choice of appropriate resistor values for the two resistors R1 and R2. Today in this tutorial we will see the interfacing optocoupler with Arduino (4N35 or MCT2E). But before that let's see what an optoisolator or optocoupler is? Optocouplers or optical isolators are designed to electrically isolate one circuit from another.
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