Introduction
A stepper motor is an electric motor that rotates in discrete step increments. The movement of each step is precise and repeatable; therefore, the motor’s position can be controlled precisely without any feedback mechanism. Nowadays, it is being used widely in 3D printers, CNC machine or laser engraving (like Snapmaker). In this tutorial, I will share the basic steps to control stepper motor movement using ESP32 board.
You can read following links to know more how stepper motor works:
Video
This video shows how to control stepper motor model 28BYJ-48 using ESP32 board.
Hardware Preparation
This is the list of items used in the video.
Sample Program
This sample program will allow user to control stepper movement through button 1 and 2 (on TTGO T-Display ESP32 board). You need to install following library on Library Manager:
- TFT_eSPI by Bodmer Version 1.4.20
| /* | |
| Tutorial: Control 28BYJ-48 Stepper Motor Using TTGO T-Display ESP32 | |
| Board: | |
| – TTGO T-Display ESP32 | |
| https://my.cytron.io/p-ttgo-t-display-esp32-1.14-display-module | |
| Output: | |
| – 12V 28BYJ-48 Stepper Motor | |
| https://my.cytron.io/c-motor-and-motor-driver/c-dc-motor/c-stepper-motor/p-12v-28byj-48-stepper-motor-plus-uln2003-driver-board | |
| Connection TTGO | Stepper Driver | |
| GND | GND | |
| 27 | IN1 | |
| 26 | IN2 | |
| 25 | IN3 | |
| 33 | IN4 | |
| Ext libraries: | |
| – TFT_eSPI by Bodmer Version 1.4.16 | |
| */ | |
| #include <SPI.h> | |
| #include <TFT_eSPI.h> | |
| TFT_eSPI tft = TFT_eSPI(); // Resolution 135 x 240 | |
| #define FF17 &FreeSans9pt7b | |
| #define FF21 &FreeSansBold9pt7b | |
| #define ROW1 0,16 | |
| #define ROW2 0,38 | |
| #define ROW3 0,60 | |
| #define ROW4 0,82 | |
| #define ROW5 0,104 | |
| #define ROW6 0,126 | |
| #define BUTTON1 35 | |
| #define BUTTON2 0 | |
| #define STEPPER_IN1 27 | |
| #define STEPPER_IN2 26 | |
| #define STEPPER_IN3 25 | |
| #define STEPPER_IN4 33 | |
| #define REVOLUTION_STEP 2048 // 1 revolution | |
| boolean stepperDirection = false; | |
| int stepperStep = 0; | |
| int stepperStepCount = 0; | |
| boolean stepperMove = false; | |
| long prevMillisStepper = 0; | |
| int intervalStepper = 2; // Minimum is 2, increase for lower speed | |
| boolean button1Pressed = false; | |
| boolean button2Pressed = false; | |
| void setup() | |
| { | |
| pinMode(BUTTON1, INPUT_PULLUP); | |
| pinMode(BUTTON2, INPUT_PULLUP); | |
| pinMode(STEPPER_IN1, OUTPUT); | |
| pinMode(STEPPER_IN2, OUTPUT); | |
| pinMode(STEPPER_IN3, OUTPUT); | |
| pinMode(STEPPER_IN4, OUTPUT); | |
| tft.init(); | |
| tft.setRotation(1); | |
| tft.fillScreen(TFT_BLACK); | |
| tft.setFreeFont(FF21); | |
| tft.setTextColor(TFT_BLUE); | |
| tft.setCursor(ROW1); | |
| tft.print("BUTTON1"); | |
| tft.setCursor(ROW5); | |
| tft.print("BUTTON2"); | |
| tft.setFreeFont(FF17); | |
| tft.setTextColor(TFT_RED); | |
| tft.setCursor(ROW2); | |
| tft.print("Clockwise"); | |
| tft.setCursor(ROW6); | |
| tft.print("Counter Clockwise"); | |
| } | |
| void loop() | |
| { | |
| if (digitalRead(BUTTON1) == LOW && | |
| button1Pressed == false) { | |
| button1Pressed = true; | |
| stepperDirection = false; | |
| stepperMove = true; | |
| stepperStepCount = 0; | |
| stepperStep = 1; | |
| } | |
| else if (digitalRead(BUTTON1) == HIGH && | |
| button1Pressed == true) { | |
| button1Pressed = false; | |
| } | |
| if (digitalRead(BUTTON2) == LOW) { | |
| stepperDirection = true; | |
| stepperMove = true; | |
| stepperStepCount = 0; | |
| stepperStep = 1; | |
| } | |
| else if (digitalRead(BUTTON2) == HIGH && | |
| button2Pressed == true) { | |
| button2Pressed = false; | |
| } | |
| if (millis() – prevMillisStepper > intervalStepper) { | |
| if (stepperMove == true) { | |
| if (stepperDirection) { | |
| if (stepperStep++ >= 3) { | |
| stepperStep = 0; | |
| } | |
| } | |
| else { | |
| if (stepperStep– == 0) { | |
| stepperStep = 3; | |
| } | |
| } | |
| if (stepperStepCount++ == REVOLUTION_STEP) { | |
| stepperMove = false; | |
| stepperStep = 4; | |
| } | |
| switch (stepperStep) { | |
| case 0: | |
| digitalWrite(STEPPER_IN1, HIGH); | |
| digitalWrite(STEPPER_IN2, LOW); | |
| digitalWrite(STEPPER_IN3, LOW); | |
| digitalWrite(STEPPER_IN4, LOW); | |
| break; | |
| case 1: | |
| digitalWrite(STEPPER_IN1, LOW); | |
| digitalWrite(STEPPER_IN2, HIGH); | |
| digitalWrite(STEPPER_IN3, LOW); | |
| digitalWrite(STEPPER_IN4, LOW); | |
| break; | |
| case 2: | |
| digitalWrite(STEPPER_IN1, LOW); | |
| digitalWrite(STEPPER_IN2, LOW); | |
| digitalWrite(STEPPER_IN3, HIGH); | |
| digitalWrite(STEPPER_IN4, LOW); | |
| break; | |
| case 3: | |
| digitalWrite(STEPPER_IN1, LOW); | |
| digitalWrite(STEPPER_IN2, LOW); | |
| digitalWrite(STEPPER_IN3, LOW); | |
| digitalWrite(STEPPER_IN4, HIGH); | |
| break; | |
| default: | |
| digitalWrite(STEPPER_IN1, LOW); | |
| digitalWrite(STEPPER_IN2, LOW); | |
| digitalWrite(STEPPER_IN3, LOW); | |
| digitalWrite(STEPPER_IN4, LOW); | |
| break; | |
| } | |
| } | |
| prevMillisStepper = millis(); | |
| } | |
| } |
Thank You
References:
Thanks for reading this tutorial. If you have any technical inquiries, please post at Cytron Technical Forum.
2 thoughts on “Control Stepper Motor 28BYJ-48 Using TTGO T-Display ESP32”
This code is for inbuilt button in ESP32 if I change pin no. from
#define BUTTON1 35
#define BUTTON2 0
to
#define BUTTON1 34
#define BUTTON2 35
it is not working. How could I resolve it, And how could I add more rotations in it ?
no display from the OLED ? how to fix it ?