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Arduino Tutorial 9: Understanding Ohm’s Law and Simple Circuit Design

As we learn more about programming the Arduino, we become more and more excited about connecting and controlling simple circuits. In order to do this, we need to begin to understand how to design and analyze the circuits we are building. In this lesson we introduce you to Ohm’s Law and some techniques that will allow you to design and analyze simple series circuits. If you want to follow along at home, you can order the Arduino Kit we are using HERE. The nice digital voltmeter used in the lesson is available HERE.

 

Arduino Tutorial 8: Understanding Pulse Width Modulation (PWM) and the Arduino Analog Write Command

In Lesson 7, we learned how we can get in-between voltages from the Arduino pins using the analogWrite command. Actually, this command only approximates analog voltages, and does not produce actual analog signals. It works by quickly turning the voltage to the pin on and off. For example, if you ask for 2.5 volts, it will quickly switch the pin on, with it on 50% of the time and off 50% of the time. Similarly, if you asked for 1 volt, it is really switching 5 volts on and off quickly. For this case, it would be on 20% of the time and off 80% of the time. This technique is called Pulse Width Modulation. In this video we show you the actual waveforms coming from the analogWrite command on an oscilloscope. If you want to follow this lesson at home, you can get the Arduino kit we are using HERE.

Arduino Tutorial 7: Understanding the Arduino Analog Write Command

In earlier lessons we learned how to turn pins on and off with the Arduino digitalWrite command. This is great if you only want 0 or 5 volts. In this lesson we show how you can get the in between values by using the analogWrite command. In later lessons we will show more specifically how analogWrite works, but this present lesson gets you started, and shows you how to control brightness of an LED. In all these lessons we are using the Arduino Super Starter Kit, which you can pick up HERE.