Arduino 59: Step Motor
This time were going to talk about this here. This is a step motor. Okay, you see, it so looks already a little bit different than the dc motor or the servo motor. It has much more connections well and a stepper motor. What is it? Okay, a stepper motor actually can turn left, can turn right, but not any to any position. The position of the rotor can only be changed in steps right, so how is this working? The internal construction might differ, yeah or the first for sure, but from principle from basic principle. You can think about that here that you have somewhere here, lets, say a coil and here the next coil all right on the outside and this data. So here is one coil, and here we have a second coil theyre, both equally strong. Now imagine we have here something which is attracted to a magnetic field right if we turn on this coil, this will move exactly to this position, so we will see it standing like this. Okay. If we turn on both coils yeah, then we will see it ill. Make it brown the middle position exactly in the middle of those two yeah and then, if youre, turning off this coil, we will see the middle part, the rotating part, pointing to this coil yeah. So if we move, if we first put this, then both then this, then we are moving in steps yeah and thats it. This is the basic principle of a stepper motor were turning on and off little magnets in there and the magnets will move the rotating part into a certain direction and if we turn it the other way around it simply by switching on and off the coils there.
In a different pattern, it will move in the other direction yeah and it will even have quite a moment to blocking moment. This is how a stepper motor from principle is working. The reality is a little bit more complex, but you can think about its working like that. Okay, this should be sufficient for us. This specific stepper motor even has a gearbox inside. So of course, the shaft you see the shaft is out of the center. So this already indicates: oh, there must be some gears, so there is also ratio between the rotating of this shaft and the internal rotating of the rotor. Okay, usual sizes. Parameters of a stepping motor are how many steps per rotation the internal part here. This one has 64 steps by rotation Music. These are 5.6 to 5 degree, okay, so every time i change something on the coil, the internal part will move 5.6 degrees in steps. Okay, the gearbox ratio is 1 divided by 64., so if the internal part is doing 64 rotations, the external part is only doing one yeah. So externally it looks like we have 4096 64 times 64 steps per rotation. This is really tiny. You can only feel it at the beginning, yeah it will okay and of course we need some driving element. Of course, we again have the the case that our arduino is not powerful enough, so we have to use here a driving element, motor driver, stepper motor driver.
You also have it in your breadboard in your starter kit. Looking like this, the connector is fitting perfectly inside, and here these are the in one to infor. We can control with our arduino okay, so this is how a stepper motor is working and how we can control this with our arduino. What to do, we will see in next video for this time.