Hi, I'm new to arduino and have been trying out how to control the stepper motor speed using a potentiometer. I found a video in youtube that is pretty nifty.
How To Make Stepper Motor Speed Controller using A4988 Stepper Motor Driver | Arduino Stepper Motor.
The setup is supposed to control a stepper motor's speed. It has 3 buttons, clockwise turning, stop/free mode, anticlockwise turning. It also has a potentiometer that controls the motor's speed using map() and delayMicroseconds.
I followed his code but instead I used an i2c 16x02 LCD. My problem is, the stepper motor does not change its speed whenever I turn the potentiometer, but it does turn off if the potentiometer is at the minimum. I used a 1.2 A nema 17 motor and it turns just fine. I suspect that it might be how the stepper motor is controlled using map() and delayMicroseconds or the wiring i have since I used an i2c lcd display instead of the regular one. I also want to adjust it so that I can go to higher speeds like 600rpm above. I tried reading but could not, for the life of me, get it to work. What might be causing the issue?
Here is the code I have modified slightly for i2c use from the video:
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
#define potentiometer A0 //10k Variable Resistor
#define bt_F A1 // Clockwise Button
#define bt_S A2 // Stop Button
#define bt_B A3 // Anticlockwise Button
#define dirPin 8 //8Pin of Arduino--Direction of stepper motor driver
#define stepPin 9 //9Pin of Arduino--Step of stepper motor driver
#define enPin 10 //10Pin of Arduino--Enabled of stepper motor driver
int read_ADC;
int Speed_LCD, Speed_Delay;
int Mode=1, flag=0;
void setup() { // put your setup code here, to run once
lcd.init();
lcd.backlight();
lcd.clear();
pinMode(potentiometer, INPUT); // declare potentiometer as input
pinMode(bt_F, INPUT_PULLUP); // declare bt_F as input
pinMode(bt_S, INPUT_PULLUP); // declare bt_S as input
pinMode(bt_B, INPUT_PULLUP); // declare bt_B as input
pinMode(dirPin, OUTPUT); // declare as output for Direction of stepper motor driver
pinMode(stepPin, OUTPUT); // declare as output for Step of stepper motor driver
pinMode(enPin, OUTPUT); // declare as output for Enabled of stepper motor driver
lcd.begin(16,2);
lcd.setCursor(0,0);
lcd.print("Start Up");
lcd.setCursor(0,1);
lcd.print("Page");
delay(2000); // Waiting for a while
lcd.clear();
}
void loop() {
read_ADC = analogRead(potentiometer); // read analogue to digital value 0 to 1023
Speed_Delay = map(read_ADC, 0, 1023, 5000, 10); //value map for Microstep resolution Delay
Speed_LCD = map(read_ADC, 0, 1023, 0, 100); //value map to Display on the LCD
lcd.setCursor(0,0);
lcd.print(" Speed: ");
lcd.print(Speed_LCD);
lcd.print("% ");
if(digitalRead (bt_F) == 0){Mode = 2; digitalWrite(enPin, LOW);} //For Clockwise
if(digitalRead (bt_S) == 0){ //For Stop
if(flag==0){flag=1;
if(Mode>1)Mode=1;
else{Mode=!Mode;
if(Mode==0)digitalWrite(enPin, HIGH);
else digitalWrite(enPin, LOW);
}
delay(100);
}
}else{flag=0;}
if(digitalRead (bt_B) == 0){Mode = 3; digitalWrite(enPin, LOW);} //For Anticlockwise
lcd.setCursor(0,1);
if(Mode==0)lcd.print(" Free ");
else if(Mode==1)lcd.print(" Stop ");
else if(Mode==2)lcd.print(" Clockwise ");
else if(Mode==3)lcd.print(" Anticlockwise ");
if(Speed_LCD>0 && Mode>1){
if(Mode==2)digitalWrite(dirPin, LOW);// Stepper motor rotates CW (Clockwise)
else digitalWrite(dirPin, HIGH);// Stepper motor rotates CCW (Anticlockwise)
digitalWrite(stepPin, HIGH);
delayMicroseconds(Speed_Delay);
digitalWrite(stepPin, LOW);
delayMicroseconds(Speed_Delay);
}
}
and here is my schematic diagram:
for reference, here is the original diagram and reference code:
#include <LiquidCrystal.h>
LiquidCrystal lcd(2, 3, 4, 5, 6, 7);
#define potentiometer A0 //10k Variable Resistor
#define bt_F A1 // Clockwise Button
#define bt_S A2 // Stop Button
#define bt_B A3 // Anticlockwise Button
#define dirPin 8 //8Pin of Arduino--Direction of stepper motor driver
#define stepPin 9 //9Pin of Arduino--Step of stepper motor driver
#define enPin 10 //10Pin of Arduino--Enabled of stepper motor driver
int read_ADC;
int Speed_LCD, Speed_Delay;
int Mode=1, flag=0;
void setup() { // put your setup code here, to run once
pinMode(potentiometer, INPUT); // declare potentiometer as input
pinMode(bt_F, INPUT_PULLUP); // declare bt_F as input
pinMode(bt_S, INPUT_PULLUP); // declare bt_S as input
pinMode(bt_B, INPUT_PULLUP); // declare bt_B as input
pinMode(dirPin, OUTPUT); // declare as output for Direction of stepper motor driver
pinMode(stepPin, OUTPUT); // declare as output for Step of stepper motor driver
pinMode(enPin, OUTPUT); // declare as output for Enabled of stepper motor driver
lcd.begin(16,2);
lcd.setCursor(0,0);
lcd.print(" WELCOME To My ");
lcd.setCursor(0,1);
lcd.print("YouTube Channel");
delay(2000); // Waiting for a while
lcd.clear();
}
void loop() {
read_ADC = analogRead(potentiometer); // read analogue to digital value 0 to 1023
Speed_Delay = map(read_ADC, 0, 1023, 5000, 10); //value map for Microstep resolution Delay
Speed_LCD = map(read_ADC, 0, 1023, 0, 100); //value map to Display on the LCD
lcd.setCursor(0,0);
lcd.print(" Speed: ");
lcd.print(Speed_LCD);
lcd.print("% ");
if(digitalRead (bt_F) == 0){Mode = 2; digitalWrite(enPin, LOW);} //For Clockwise
if(digitalRead (bt_S) == 0){ //For Stop
if(flag==0){flag=1;
if(Mode>1)Mode=1;
else{Mode=!Mode;
if(Mode==0)digitalWrite(enPin, HIGH);
else digitalWrite(enPin, LOW);
}
delay(100);
}
}else{flag=0;}
if(digitalRead (bt_B) == 0){Mode = 3; digitalWrite(enPin, LOW);} //For Anticlockwise
lcd.setCursor(0,1);
if(Mode==0)lcd.print(" Free ");
else if(Mode==1)lcd.print(" Stop ");
else if(Mode==2)lcd.print(" Clockwise ");
else if(Mode==3)lcd.print(" Anticlockwise ");
if(Speed_LCD>0 && Mode>1){
if(Mode==2)digitalWrite(dirPin, LOW);// Stepper motor rotates CW (Clockwise)
else digitalWrite(dirPin, HIGH);// Stepper motor rotates CCW (Anticlockwise)
digitalWrite(stepPin, HIGH);
delayMicroseconds(Speed_Delay);
digitalWrite(stepPin, LOW);
delayMicroseconds(Speed_Delay);
}
}
