Servo motors tend to work from the 0-6V range, especially the hobby servos we are used to seeing in the Makersphere. In order to control the rotation, we send a pulse of a variable width on the signal wire (the power and ground wires used as references for the signal). If you aren't familiar with it, a pulse is simply a square waveform that goes from 0V to another voltage for a set period of time, before returning to 0V. The servo will turn left or right according to the width of this pulse. The idea of using pulses to control a servo’s position can seem a little backward at first, take a look at this diagram to get a more intuitive understanding of how it all works. Essentially there is a neutral position that the servo motor’s circuitry will hold at, this will be defined by a pulse width (let’s call it 1ms for this example). Hypothetically, imagine the 1ms pulse that holds our servo at neutral will hold that position indefinitely. If we send a pulse that is shorter than the 1ms neutral pulse ( 1ms ) and the motor will turn fractionally toward maximum rotation (180 degrees). The circuitry that calculates this fractional amount of rotation either side of neutral is a lot more complicated than this simplification. That should give you a good idea of the way it works, though. This theory behind the servo isn’t too relevant when we are programming with the Arduino either. There is a library that we import that takes care of most of this PWM talk behind the scenes. We can now write a position to the servo using.Create a variable for the position of the servo (or just use an integer value).Attach our servo to a pin, this pin will be the signal pin for our servo and uses the.Name our servo motor as a servo, this is done using the Servo function.The basics of using the servo library includes the following steps: The library is known as the Servo library and you can see Arduino’s reference page for all the different functions of that library. We are going to use an Arduino Uno and a small hobby servo in this tutorial.
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