Circuit diagram to control Nema 17 stepper motor with Arduino

Circuit Diagram
Circuit diagram to control Nema 17 motor with Arduino is given in the above image. As A4988 module has a built-in translator that means we only need to connect the Step and Direction pins to Arduino. Step pin is used for controlling the steps while the direction pin is used to control the direction. Stepper motor is powered using a 12V power source, and the A4988 module is powered via Arduino. Potentiometer is used to control the direction of the motor.

If you turn the potentiometer clockwise, then stepper will rotate clockwise, and if you turn potentiometer anticlockwise, then it will rotate anticlockwise. A 47 µf capacitor is used to protect the board from voltage spikes. MS1, MS2, and MS3 pins left disconnected, that means the stepper driver will operate in full-step mode.

Complete connections for Arduino Nema 17 A4988 given in below table.

S.NO.	A4988 Pin	Connection
1	VMOT	+ve Of Battery
2	GND	-ve of Battery
3	VDD	5V of Arduino
4	GND	GND of Arduino
5	STP	Pin 3 of Arduino
6	DIR	Pin 2 of Arduino
7	1A, 1B, 2A, 2B	Stepper Motor

Code Explanation

Complete code with working video control Nema 17 with Arduino is given at the end of this tutorial, here we are explaining the complete program to understand the working of the project.

First of all, add the stepper motor library to your Arduino IDE. You can download the stepper motor library from here.

After that define the no of steps for the NEMA 17.  As we calculated, the no. of steps per revolution for NEMA 17 is 200.

#include <Stepper.h>
#define STEPS 200

After that, specify the pins to which driver module is connected and define the motor interface type as Type1 because the motor is connected through the driver module.

Stepper stepper(STEPS, 2, 3);
#define motorInterfaceType 1

Next set the speed for stepper motor using stepper.setSpeed function. Maximum motor speed for NEMA 17 is 4688 RPM but if we run it faster than 1000 RPM torque falls of quickly.

void setup() {
    stepper.setSpeed(1000);

Now in the main loop, we will read the potentiometer value from A0 pin. In this loop, there are two functions one is potVal, and the other is Pval. If the current value, i.e., potVal is higher than the previous value, i.e., Pval than it will move ten steps in the clockwise direction and if the current value is less than previous value than it will move ten steps in the counter-clockwise direction.

potVal = map(analogRead(A0),0,1024,0,500);
  if (potVal>Pval)
      stepper.step(10);
  if (potVal<Pval)
      stepper.step(-10);

Pval = potVal;

Now connect the Arduino with your laptop and upload the code into your Arduino UNO board using Arduino IDE, select the Board and port no and then click on the upload button.

Now you can control the direction of Nema17 stepper motor using the potentiometer. The complete working of the project is shown in the video below. If you have any doubts regarding this project, post them in the comment section below.   

Code

#include <Stepper.h> 
#define STEPS 200

// Define stepper motor connections and motor interface type. Motor interface type must be set to 1 when using a driver
Stepper stepper(STEPS, 2, 3); // Pin 2 connected to DIRECTION & Pin 3 connected to STEP Pin of Driver
#define motorInterfaceType 1
int Pval = 0;
int potVal = 0;

void setup() {
  // Set the maximum speed in steps per second:
  stepper.setSpeed(1000);
}
void loop() {
 
  potVal = map(analogRead(A0),0,1024,0,500);
  if (potVal>Pval)
      stepper.step(10);
  if (potVal<Pval)
      stepper.step(-10);

Pval = potVal;

Which is better for 4-Wire, 6-Wire and 8-Wire Stepping Motor

I have a stepper motor with either 4, 6, or 8 lead wires available to connect to a stepper drive. What is the difference between these wiring types, and does this affect how I connect the motor to my drive?

Solution

The basic operation of any stepper motor relies on the use of inductive coils which push or pulls the rotor through its rotation when they are energized. A pair of wire leads coming from a stepper motor will correspond to at least one of these windings and possibly more depending on the motor type. In each of the following cases a chassis ground lead is also pictured to ensure the motor is correctly grounded.

 

• 4-Wire Stepper Motors

While many motors take advantage of 6- and 8-wire configurations, the majority of bipolar (one winding per phase) stepper motors provide four wires to connect to the motor windings. A basic 4-wire  Nema 34 - 86 x 86m stepper motor is shown in Figure 1. Connecting this motor type is very straightforward and simply requires connecting the A and A' leads to the corresponding phase outputs on your motor drive.

 

Figure 1: 4-Wire Stepper Motor

 

• 6-Wire Stepper Motors

A 6-wire stepper motor is similar to a 4-wire configuration with the added feature of a common tap placed between either end of each phase as shown in Figure 2. Stepper motors with these center taps are often referred to as unipolar motors. This wiring configuration is best suited for applications requiring high torque at relatively low speeds. Most National Instruments stepper motor interfaces do not support 6-Wire stepper motors, although some motors do not require the center taps to be used and can be connected normally as a 4-wire motor.
 

Figure 2: 6-Wire Stepper Motor (Left) 8-Wire Stepper Motor in Parallel (Right)

 

• 8-Wire Stepper Motors

Some motors are also offered in 8-Wire configurations allowing for multiple wiring configurations depending on whether the motor's speed or torque is more important. An 8-wire stepper motor can be connected with the windings in either series or parallel. Figure 3 shows an 8-Wire stepper motor with both windings of each phase connected in series. This configuration is very similar to the 6-wire configuration and similarly offers the most torque per amp at the expense of high speed performance.

 

Figure 3: 8-Wire Stepper Motor (Series Configuration)

 

It is also possible to connect an 8-wire stepper motor with the windings of each phase connected in parallel as shown in Figure 4. This configuration will enable better high speed operation while requiring more current to produce the rated torque. This connection type is sometimes known as parallel bipolar wiring.

 

Figure 4: 8-Wire Nema Stepper Motor (Parallel Configuration)

Although every stepper motor operates in the same basic way, it is important to understand the difference between each wiring type and when each should be used.

http://www.apsense.com/article/steps-per-revolution-for-nema17.html

http://www.weshare.com.hk/shikakiki/articles/4674579

Common Discussions About Peculiarities of Step Motors

Help'. This is a common word during discussions involving peculiarities of step motors, which can have 4, 5, 6, and 8 wires. But today, I can say that this type of engine is no longer such a difficult challenge, as they are starting to get more and more standardized.

Step 1: Most Common Engines

Here, we will talk about the most common china stepping motors: of 4, 5, 6, and 8 wires, which can be unipolar or bipolar. The best known of these is the bipolar, 4-wire, which is what we use, for example, with several drives, such as the TB6600, with the printer driver Router 4988, and with the DRV8825, among others. The 5-wire motors are unipolar. In 6-wire and 8-wire, these are rated as unipolar or bipolar depending on how the driver is connected.

Step 2: Coils

Most of the up-to-date stepper motors that I have are with eight windings. It is not because only two coils appear on the schematic that is just that.
So, as we're talking about this, I’m going to answer a question from a follower, Natan Bittencourt, and explain this better: "Fernando, I did not quite understand the issue of stepper motor resolution. Does it have to do with the amount of coils inside the engine?

 Can I vary the amount of steps within a complete rotation just by
varying the intensity of the electric current in the coils?”
The question essentially is this: if there were more coils in the engine, would it have more resolution? The answer is no. What causes resolution in the stepper motor is the number of phases with the number of teeth. It's almost always that. So when you search the web, you will find these diagrams with north pole with south pole.
This has the good and bad side. It serves synthetically, it has its utility, but it is bad to make a parallel with the stepper motor in the direction of the teeth, because when you play the sequence on the coil, you are millimetrically grinding your teeth. So beware of this kind of representation.

But another thing I want to address today is the waves.
In this image, we have the single step wave, the half step wave, and the micro step wave of 1/8. So the more you increase the micro pitch, 1/8, 1/16 (used frequently by 3D printers), 1/32, the drivers tend to throw a sine wave over the coils. However, I don’t see this in practice. This is because most of the drivers we buy are cheaper ones. Even the 17HS19-1684S-PG100, and 34HS38-4004D-SG13 are of the more simplified type and cheaper as a result. I have to say, however, that they are intelligent, do a lot of things, control micro-steps, but they don’t go as far as the last consequence of generating a sine wave at the output.

Best Planetary Gear Unipolar Stepper Motor 9.6V 0.4A

9.6V, 0.4A, Planetary Gear Unipolar Stepper Motor 

Unipolar Geared Stepper Motor
Rated Voltage: 9.6V
Current / Phase: 0.4A
Resistance / Phase: 24 Ohms
Inductance / Phase: 15 mH
Reduction Ratio:172:1
Max Rated Torque: 150 Kg.cm
Short Permissible Torque: 450 Kg.cm
Shaft: D-Shaped
Back Shaft for Encoder

The 9.6V, 0.4A, Planetary Gear Unipolar Stepper Motor is a unipolar stepper motor with 172:1 planetary gearing. The gearbox is rated for a maximum of 150 kg-cm despite the motor and gear ratio being able to provide 275.2 kg-cm.
Specifications

Planetary Gearbox:
Ring Material: Metal
Bearing at output: Ball bearings
Max. Radial load (10mm from flange): ≤80N
Max. Shaft axial load: ≤30N
Radial play of shaft (near to flange): ≤0.06 mm
Axial play of shaft: ≤0.3mm
Backlash at no-load: ≤1.5°

42STH Hybrid Stepping Motor
Rated Voltage (V): 9.6
Current /Phase (A): 0.4
Resistance /Phase: 24
Inductance /Phase(mH): 15
Holding Torque (kg.cm): 1.6
No of Leads: 6
Rotor Inertia (g-m2): 35
Weight (kg)0.22
Length L1(mm): 34
Max. Gear Ratio: ≤1:264

42JX150K Planetary Gearbox
Reduction ratio: 172
Number of gear trains: 4
Length(L2) mm: 52.6
Max. rated torque (kg.cm): 150
Short time permissible torque(kg.cm): 450
Efficiency: 66%
Weight: 620

Dimensions
 Size: 42H x 42W x 86.6L mm
 Weight: 840 g
 Shaft Diameter: 10 mm
Shaft Length: 19 mm

A Basic Guide on Encoder Devices Operating