ESP32, Motor/ Robot

Control Stepper Motor 28BYJ-48 Using TTGO T-Display ESP32

by Idris
December 11, 2019

28BYJ-48, ESP32, Stepper Motor

Control stepper motor with ESP32 and Arduino.

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.

TTGO T-Display ESP32 1.14 Display Module

12V 28BYJ-48 Stepper Motor + ULN2003 Driver Board

LiPo Rechargeable Battery 11.1V 500mAh 25C

Breadboard

Jumper Wire

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(); 
   } 
  } 