Stepper motors are increasingly taking its position in the world of the electronics. Starting from a normal Surveillance camera to a complicated CNC machines/Robot these stepper motors are used everywhere as actuators since they provide accurate controlling. A Stepper Motor is a brushless, synchronous motor which completes a full rotation into a number of steps. In this Arduino stepper motor tutorial nosotros will learn about the most commonly available stepper motor 28-BYJ48 and how to interface it with Arduino using ULN2003 stepper motor module.

Stepper Motors:

Permit usa take a look at this 28-BYJ48 Stepper motor.

Okay, so unlike a normal DC motor this 1 has five wires of all fancy colors coming out of it and why is it so? To understand this we should kickoff know how a stepper works and what its specialty is. First of all steppers motors do not rotate, they step and and then they also known as step motors. Significant, they will move only one step at a fourth dimension. These motors have a sequence of coils present in them and these coils have to exist energized in a particular fashion to make the motor rotate. When each curlicue is beingness energized the motor takes a step and a sequence of energization volition make the motor take continuous steps, thus making it to rotate. Permit us accept a expect at the coils nowadays inside the motor to know exactly know from where these wires come from.

As you can see the motor has Unipolar five-lead coil organisation. In that location are iv coils which accept to be energized in a particular sequence. The Red wires volition exist supplied with +5V and the remaining iv wires volition be pulled to ground for triggering the respective gyre. We use a microcontroller like Arduino energize these coils in a particular sequence and make the motor perform the required number of steps.

So at present, why is this motor called the 28-BYJ48? Seriously!!! I don't know. There is no technical reason for this motor for being named so; maybe we should dive much deeper into it. Permit us look at some of the important technical information obtained from the datasheet of this motor in the picture below.

That is a head full of information, but nosotros need to wait at few of import ones to know what type of stepper we are using so that we can programme it efficiently. First nosotros know that information technology is a 5V Stepper motor since nosotros energize the Red wire with 5V. Then, nosotros also know that information technology is a 4 phase stepper motor since it had iv coils in information technology. Now, the gear ratio is given to exist 1:64. This means the shaft that you lot encounter outside volition make i complete rotation only if the motor inside rotates for 64 times. This is considering of the gears that are connected between the motor and output shaft, these gears assist in increasing the torque.

Some other of import information to notice is the Step Bending: 5.625°/64. This means that the motor when operates in 8-step sequence volition motion 5.625 degree for each step and it will have 64 steps (5.625*64=360) to complete one full rotation. You can larn more nearly working of stepper motors with ARM LPC2148, ATMega16 Microcontroller, MSP430.

Calculating the Steps per Revolution for Stepper Motor:

It is important to know how to summate the steps per Revolution for your stepper motor because only then y'all tin programme it effectively.

In Arduino we will be operating the motor in 4-step sequence so the stride angle volition be 11.25° since information technology is five.625°(given in datasheet) for 8 footstep  sequence information technology will exist 11.25° (5.625*2=11.25).

     Steps per revolution = 360/step angle

Hither, 360/eleven.25 = 32 steps per revolution.

Why so nosotros need Driver modules for Stepper motors?

Most stepper motors volition operate only with the help of a driver module. This is because the controller module (In our case Arduino) volition not be able to provide enough current from its I/O pins for the motor to operate. And then we will apply an external module like ULN2003 module as stepper motor driver. In that location are a many types of commuter module and the rating of one will change based on the blazon of motor used. The main principle for all driver modules will exist to source/sink enough current for the motor to operate.

Arduino Stepper Motor Position Command Excursion Diagram and Caption:

The circuit Diagram for the arduino stepper motor control projection is shown in a higher place. Nosotros have used the 28BYJ-48 Stepper motor and the ULN2003 Driver module. To energise the four coils of the stepper motor we are using the digital pins viii,nine,10 and 11. The driver module is powered by the 5V pin of the Arduino Lath.

Simply, power the driver with External Power supply when you are connecting some load to the steppe motor. Since I am just using the motor for sit-in purpose I have used the +5V rail of the Arduino Board. Too remember to connect the Footing of the Arduino with the ground of the Diver module.

Code for Arduino Board:

Before nosotros start programming with our Arduino, let usa understand what should really happen inside the program. As said earlier we will be using 4-step sequence method and so we will have four steps to perform for making one complete rotation.

Step	Pin Energized	Coils Energized
Footstep one	8 and 9	A and B
Step 2	9 and 10	B and C
Pace three	ten and 11	C and D
Step 4	11 and 8	D and A

The Driver module will have four LED using which we tin can bank check which coil is being energised at any given fourth dimension. The video which shows the sequence of energization can be found at the end of this tutorial.

In this tutorial we are going to write the arduino stepper motor lawmaking and for that we willprogramme the Arduino in such a way that we tin can enter the number of steps to be taken by the stepper motor through the serial monitor of the Arduino. The consummate program can exist plant at the cease of the tutorial few important lines are explained below.

The number of steps per revolution for our stepper motor was calculated to be 32; hence we enter that every bit shown in the line below

#define STEPS 32

Next y'all have to create instances in which we specify the pins to which nosotros take connected the Stepper motor.

Stepper stepper (STEPS, 8, ten, ix, eleven);

Note: The pins number are matted as 8,ten,9,xi on purpose. You have to follow the same pattern even if you change the pins to which your motor is connected.

Since we are using the Arduino stepper library, we can gear up the speed of the motor using the beneath line. The speed can range between 0 to 200 for 28-BYJ48 stepper motors.

stepper.setSpeed(200);

Now, to make the motor move ane step we can use the following line.

stepper.step(val);

The number of steps to be moved will exist provided past the variable "val". Since we have 32 steps and 64 as the gear ratio we need to movement 2048 (32*64=2048), to brand one complete rotation.

The value of the variable "val" tin exist entered by the user using the serial monitor.

Working of Stepper Motor with Arduino:

Once the connection is made the hardware should look something like this in the motion-picture show below.

Now, upload the below programme in your Arduino UNO and open the serial monitor. As discussed before we volition take to make 2048 steps to make ane complete rotation, so when we enter 2048 the motor will make one complete rotation in clockwise management by making 2048 steps. To rotate in anti-clockwise simply enter the number with "–"negative sign. So, entering  -1024 will make the motor to rotate half the fashion in anti-clock wise direction. You can enter whatever desired values, like inbound 1will make the motor to accept only one step.

Hope you understood the projection and enjoyed building it. The consummate working of the project is shown in the video below. If yous have any doubts mail service them on the comment section below our on our forums.