Overview: Control Stepper Motor with A4988 Driver & Arduino
In this tutorial we will Control the NEMA17 Stepper Motor with A4988 Driver Module & Arduino. The A4988 is a micro-stepping driver for controlling bipolar stepper motors which have a built-in translator for easy operation. Thus, we can control the stepper motor with just 2 pins from our controller. The DIR pin will control the rotation direction and the STEP pin will control the steps.
In the previous tutorial we learned Controlling the Stepper Motor with Potentiometer and also with Joystick. The 28BYJ-48 is a 5-wire unipolar stepper motor that runs on 5 volts and doesn’t require any driver. But the NEMA17 Stepper Motor is requires 8V-35V Power as the torque is too high. Therefore we need Stepper Driver Module like A4988 or DRV8825.
Bill of Materials
The following are the components required for learning this tutorial. All the components can be easily purchased from Amazon. The component purchase link is given as well.
| S.N. | Components Name | Quantity | Purchase Links |
|---|---|---|---|
| 1 | Arduino Nano Board | 1 | Amazon | AliExpress |
| 2 | A4988 Stepper Motor Driver | 1 | Amazon | AliExpress |
| 3. | NEMA17 Stepper Motor | 1 | Amazon | AliExpress |
| 4 | Electrolytic Capacitor 100uF | 2 | Amazon | AliExpress |
| 5 | 12V DC Adapter | 1 | Amazon | AliExpress |
| 6 | 5V DC Adapter | 1 | Amazon | AliExpress |
| 7 | Connecting Jumper Wires | 20 | Amazon | AliExpress |
| 8 | Breadboard | 1 | Amazon | AliExpress |
A4988 Stepper Motor Driver Module
The A4988 is a complete Microstepping Motor Driver with a built-in translator for easy operation. The breakout board from Allegro features adjustable current limiting, over-current and over-temperature protection and five different microstep resolutions. It operates from 8 V to 35 V and can deliver up to approximately 1 A per phase without a heat sink or forced airflow. It is rated for 2 A per coil with sufficient additional cooling.
Features
- Max. Operating Voltage: 35V
- Min. Operating Voltage: 8V
- Max. Current Per Phase: 2A
- Microstep resolution: Full step, ½ step, ¼ step, 1/8 and 1/16 step
- Reverse voltage protection: No
- Dimensions: 15.5 × 20.5 mm (0.6″ × 0.8″)
- Short-to-ground and shorted-load protection
- Low RDS(ON) outputs
- Thermal shutdown circuitry
A4988 Motor Driver Pinout
The A4988 driver has total of 16 pins which are as follows:
1. Power Supply Pins: The pin include VDD & VMOT & Pair of GND pins. VDD is employed for driving the interior logic circuitry which may be 3V to 5V whereas VMOT supplies power for the motor which may be 8V to 35 V.
2. Microstep Selection Pins: The A4988 driver has three-step resolution selector inputs, i.e., MS1, MS2 & MS3. By setting appropriate logic levels to those pins we will set the motors to at least one of the five-step resolutions.
3. Control Input Pins: STEP & DIR are the 2 control input pins. STEP input controls the micro-steps of the motor whereas DIR input controls the spinning direction of the motor.
4. Power States Control Pin: The A4988 has three different inputs for controlling its power states, i.e EN, RST, and SLP. The EN pin is active low input, when pulled LOW the A4988 driver is enabled. SLP Pin is active low input. Pulling this pin LOW puts the driver in sleep mode, minimizing the facility consumption. The RST is a lively low input which when pulled LOW, all STEP inputs are ignored. It also resets the driver by setting the internal translator to a motor initial stage.
5. Output Pins: There are 4 output pins as 2B, 2A, 1B, 1A. We can connect any bipolar stepper motor having voltages between 8V to 35 V to those pins.
Heat Sink Requirement
It is safe to use the A4988 Driver without a heat sink if the current rating is up to 1A. For achieving more than 1A per coil, a heat sink or other cooling method is required.
Because of the excessive power dissipation of the A4988 driver, there is a rise of temperature that can go beyond the capacity of IC, probably damaging it.
Setting Up Current Limit
Before we connect the motor we should adjust the current limiting of the driver so that the current is within the limit of the motor. We can do that by adjusting the reference voltage using the potentiometer on the board and considering this equation below.
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Current Limit = VRef x 2.5 |
For example, if the Stepper Motor is rated for 350mA, we need to adjust the reference voltage to 0.14V. Take a small screwdriver and adjust the current limit with a potentiometer until you reach the rated current.
NEMA17 Stepper Motor
NEMA 17 is a hybrid stepping motor with a 1.8° step angle (200 steps/revolution). Each phase draws 1.2 A at 4 V, allowing for a holding torque of 3.2 kg-cm. NEMA 17 Stepper motor is generally used in Printers, CNC machines and Laser Cutters. Check out Stepper Motor Calculator to calculate various stepper motor parameters.
This motor has six wires, connected to two split windings. Black, Yellow, Green wires are part of the first winding while Red, White, and Blue is part of the second winding.
Interfacing NEMA17 Stepper Motor with Arduino using A4988 Driver
Now lets connect the A4988 Stepper Motor driver to Arduino and control NEMA17 Stepper Motor. I used D2 & D3 pins to control the motor direction and step. The schematic for the connection is given below.
The VMOT pin is powered by 12V Power Supply and VDD is powered using a 5V Supply. Remember to put a large 100µF decoupling electrolytic capacitor across motor power supply pins, close to the board.
Basic Stepper Motor Control Code
Now that you have wired up the driver and set the current limit, it is time to connect the Arduino to the computer and upload some code. This sketch controls motor in a single direction.
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const int dirPin = 2; const int stepPin = 3; const int stepsPerRevolution = 200; void setup() { // Declare pins as Outputs pinMode(stepPin, OUTPUT); pinMode(dirPin, OUTPUT); } void loop() { // Set motor direction clockwise digitalWrite(dirPin, HIGH); // Spin motor slowly for(int x = 0; x < stepsPerRevolution; x++) { digitalWrite(stepPin, HIGH); delayMicroseconds(2000); digitalWrite(stepPin, LOW); delayMicroseconds(2000); } delay(1000); // Wait a second // Set motor direction counterclockwise digitalWrite(dirPin, LOW); // Spin motor quickly for(int x = 0; x < stepsPerRevolution; x++) { digitalWrite(stepPin, HIGH); delayMicroseconds(1000); digitalWrite(stepPin, LOW); delayMicroseconds(1000); } delay(1000); // Wait a second } |
Controlling Stepper Motor Spinning Direction
Using this code, the stepper motor direction can be controlled. You can rotate the motor in either clockwise direction or in anticlockwise direction. This sketch controls both the speed, the number of revolutions, and the spinning direction of the stepper motor.
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const int dirPin = 2; const int stepPin = 3; const int stepsPerRevolution = 200; void setup() { // Declare pins as Outputs pinMode(stepPin, OUTPUT); pinMode(dirPin, OUTPUT); } void loop() { // Set motor direction clockwise digitalWrite(dirPin, HIGH); // Spin motor slowly for(int x = 0; x < stepsPerRevolution; x++) { digitalWrite(stepPin, HIGH); delayMicroseconds(2000); digitalWrite(stepPin, LOW); delayMicroseconds(2000); } delay(1000); // Wait a second // Set motor direction counterclockwise digitalWrite(dirPin, LOW); // Spin motor quickly for(int x = 0; x < stepsPerRevolution; x++) { digitalWrite(stepPin, HIGH); delayMicroseconds(1000); digitalWrite(stepPin, LOW); delayMicroseconds(1000); } delay(1000); // Wait a second } |
Controlling Stepper Motor with AccelStepper Library
Stepper Motor can be controlled using the Arduino AccelStepper library. It provides an object-oriented interface for 2, 3, or 4 pin stepper motors and motor drivers.
AccelStepper significantly improves on the standard Arduino Stepper library in several ways like it supports acceleration and deceleration. It also supports multiple simultaneous steppers, with independent concurrent stepping on each stepper. Even very slow speeds are also supported
The following code shows all the above-mentioned features.
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#include <AccelStepper.h> // Define stepper motor connections and motor interface type. Motor interface type must be set to 1 when using a driver: #define dirPin 2 #define stepPin 3 #define motorInterfaceType 1 // Create a new instance of the AccelStepper class: AccelStepper stepper = AccelStepper(motorInterfaceType, stepPin, dirPin); void setup() { // Set the maximum speed in steps per second: stepper.setMaxSpeed(1000); } void loop() { // Set the current position to 0: stepper.setCurrentPosition(0); // Run the motor forward at 200 steps/second until the motor reaches 400 steps (2 revolutions): while(stepper.currentPosition() != 400) { stepper.setSpeed(200); stepper.runSpeed(); } delay(1000); // Reset the position to 0: stepper.setCurrentPosition(0); // Run the motor backwards at 600 steps/second until the motor reaches -200 steps (1 revolution): while(stepper.currentPosition() != -200) { stepper.setSpeed(-600); stepper.runSpeed(); } delay(1000); // Reset the position to 0: stepper.setCurrentPosition(0); // Run the motor forward at 400 steps/second until the motor reaches 600 steps (3 revolutions): while(stepper.currentPosition() != 600) { stepper.setSpeed(400); stepper.runSpeed(); } delay(3000); } |
Stepper Motor Acceleration & deceleration Code
The following sketch will add acceleration and deceleration to the movements of the stepper motor. The motor will run back and forth with a speed of 200 steps per second and an acceleration of 30 steps per second.
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#include <AccelStepper.h> #define dirPin 2 #define stepPin 3 #define motorInterfaceType 1 // Create a new instance of the AccelStepper class: AccelStepper stepper = AccelStepper(motorInterfaceType, stepPin, dirPin); void setup() { // Set the maximum speed and acceleration: stepper.setMaxSpeed(200); stepper.setAcceleration(30); } void loop() { // Set the target position: stepper.moveTo(600); // Run to target position with set speed and acceleration/deceleration: stepper.runToPosition(); delay(1000); // Move back to zero: stepper.moveTo(0); stepper.runToPosition(); delay(1000); } |
Control NEMA17 Stepper Motor with A4988 & Potentiometer
The stepper motor can be controlled using Potentiometer as well. I used a 10K Potentiometer and connected it to the A0, analog pin of the Arduino Nano board. The voltage fed to the Analog pin of Arduino can be used as a reference voltage to control the speed of the Stepper Motor. The connection diagram is given below.
Copy the code from below and upload it to the Arduino Nano Board.
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/ Defines pins numbers const int stepPin = 3; const int dirPin = 4; int customDelay,customDelayMapped; // Defines variables void setup() { // Sets the two pins as Outputs pinMode(stepPin,OUTPUT); pinMode(dirPin,OUTPUT); digitalWrite(dirPin,HIGH); //Enables the motor to move in a particular direction } void loop() { customDelayMapped = speedUp(); // Gets custom delay values from the custom speedUp function // Makes pules with custom delay, depending on the Potentiometer, from which the speed of the motor depends digitalWrite(stepPin, HIGH); delayMicroseconds(customDelayMapped); digitalWrite(stepPin, LOW); delayMicroseconds(customDelayMapped); } // Function for reading the Potentiometer int speedUp() { int customDelay = analogRead(A0); // Reads the potentiometer int newCustom = map(customDelay, 0, 1023, 300,4000); // Convrests the read values of the potentiometer from 0 to 1023 into desireded delay values (300 to 4000) return newCustom; } |
Video Tutorial & Guide
14 Comments
Why not using the Arduino 5V output to power the A4988 driver, instead of using another external 5V power source? Thank you!
Arduino can provide only about 20ma per output in, and thiw is not enough to move the more than 50 times higher current for the motor. That is the reason of using the ‘driver circuit’. Small current from Arduino becomes ‘big’ current for the motor.
Hello, I was wondering if it would be possible to power both the arduino and stepper motor (via the A4988) with a single power supply, instead of 2 (one 5V and one 12V…). I am planning to use this for a project which requires a tiny space and it would be preferable for me to be able to only have 1 wire going in to power the circuit rather than 2. Thank you!
Yes. You could. BUT :5v is very low and you will need more current. If you can use a 12v power suply and add a 5v regulator (7805 ?) for the arduino part, it could help you overcomming this. A small heatsink on regulator will do as arduino itself will need a few ma.
Can you clarify what capacitor should be used for the 5v power supply? Bill of Materials implies 100 uF, schematic says 10 uF, video says 47 uF or more. Also, can I use a ceramic capacitor? My (limited) understanding is that for this application, ceramic is fine, and anywhere from 10 to 100 uF will probably be fine… but I’d like to have confirmation and also know what is ‘ideal’.
You can use any capacitor from 10uF to 100uF
So every NEMa17 I come across has a operational voltage of around 3V. still the only thing I can find is people driving it with 12V and a A4988.
wont that damage the motor?
What will damage the motor is current (Amperes). And what is keeping current in balance is A4988. So 3v is just the lowest possible voltage to achieve the current needed to move motor. A4988 works like a current limiter so we always drive motor with the correct current even when voltage is more than 3v. More voltage helps in using thinner wires in circuit and so keep it cooler.
Hello, I was wondering if it would be possible to power both the arduino and stepper motor (via the A4988) with a single power supply, instead of 2 (one 5V and one 12V…). I am planning to use this for a project which requires a tiny space and it would be preferable for me to be able to only have 1 wire going in to power the circuit rather than 2. Thank you!
I’ll start off with, I am a beginner, so please forgive me if I am incorrect, but it appears that the trace routing from the 5V and 12V plugs are routed incorrectly. The A4988 VMOT is connected to the 5V and the VDD is connected to the 12V.
The Arduino Nano will accept 12v on the Vin pin and produce 5v on the 5v pin via the onboard regulator. The 5v regulator is capable of about 800mA. It can power up to 3 A4988 drivers, a bluetooth driver (HC-05) and one or two low power I2C devices as well as the MCU. On the Nano board, this 5v output is isolated from the 5v on the USB by means of a diode. I haven’t played with a Nano 33 yet so I’m not sure if this information applies to these newer Arduino devices which are otherwise not 5v logic tolerant. I believe the schematics for these board are available on the Arduino web page as they are open source.
I’m sorry to be ignorant on this but how do i set the ‘reference voltage’ on the driver? What do i connect to what? I can check the voltage of a battery but that generally has volage within.
what the reason of losing steps
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