Hello everyone, I am working on a camera that tracks an object while sliding . The camera rotates with the 28byj-48 stepper motor. In order to have the best accuracy I need to command this motor with a specific angle.
I coded a function that convert the angle required in number of steps . But when I tried this function with 360° , the motor rotates for only about 250° and I don't understand why ! If any of you have ideas on how I can get a correct angle I'll be glad to know it.
(I don't want to use an encoder, even it is the best answer. I want to use the steps of the motor).
I am using a arduino nano.
Thank you ! Here's my code:
#define SW A2
#include <stdio.h>
#include <Wire.h> // Library for I2C communication
int motorPin1 = 4; // Blue - 28BYJ48 pin 1
int motorPin2 = 5; // Pink - 28BYJ48 pin 2
int motorPin3 = 6; // Yellow - 28BYJ48 pin 3
int motorPin4 = 7; // Orange - 28BYJ48 pin 4
int motorSpeed;
int pas = 0;
int resolution_stepper2 = 4096;
void setup() {
// put your setup code here, to run once:
pinMode(motorPin1, OUTPUT);
pinMode(motorPin2, OUTPUT);
pinMode(motorPin3, OUTPUT);
pinMode(motorPin4, OUTPUT);
pinMode(Ya,OUTPUT);
pinMode(SW,INPUT_PULLUP);
Serial.begin(9600);
motorSpeed = 1;
}
void loop() {
angle2step(360);
delay(3000);
}
void counterclockwise (){
// 1
digitalWrite(motorPin1, HIGH);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin4, LOW);
delay(motorSpeed);
// 2
digitalWrite(motorPin1, HIGH);
digitalWrite(motorPin2, HIGH);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin4, LOW);
delay (motorSpeed);
// 3
digitalWrite(motorPin1, LOW);
digitalWrite(motorPin2, HIGH);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin4, LOW);
delay(motorSpeed);
// 4
digitalWrite(motorPin1, LOW);
digitalWrite(motorPin2, HIGH);
digitalWrite(motorPin3, HIGH);
digitalWrite(motorPin4, LOW);
delay(motorSpeed);
// 5
digitalWrite(motorPin1, LOW);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin3, HIGH);
digitalWrite(motorPin4, LOW);
delay(motorSpeed);
// 6
digitalWrite(motorPin1, LOW);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin3, HIGH);
digitalWrite(motorPin4, HIGH);
delay (motorSpeed);
// 7
digitalWrite(motorPin1, LOW);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin4, HIGH);
delay(motorSpeed);
// 8
digitalWrite(motorPin1, HIGH);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin4, HIGH);
delay(motorSpeed);
}
//////////////////////////////////////////////////////////////////////////////
//set pins to ULN2003 high in sequence from 4 to 1
//delay "motorSpeed" between each pin setting (to determine speed)
void clockwise(){
// 1
digitalWrite(motorPin4, HIGH);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin1, LOW);
delay(motorSpeed);
// 2
digitalWrite(motorPin4, HIGH);
digitalWrite(motorPin3, HIGH);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin1, LOW);
delay (motorSpeed);
// 3
digitalWrite(motorPin4, LOW);
digitalWrite(motorPin3, HIGH);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin1, LOW);
delay(motorSpeed);
// 4
digitalWrite(motorPin4, LOW);
digitalWrite(motorPin3, HIGH);
digitalWrite(motorPin2, HIGH);
digitalWrite(motorPin1, LOW);
delay(motorSpeed);
// 5
digitalWrite(motorPin4, LOW);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin2, HIGH);
digitalWrite(motorPin1, LOW);
delay(motorSpeed);
// 6
digitalWrite(motorPin4, LOW);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin2, HIGH);
digitalWrite(motorPin1, HIGH);
delay (motorSpeed);
// 7
digitalWrite(motorPin4, LOW);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin1, HIGH);
delay(motorSpeed);
// 8
digitalWrite(motorPin4, HIGH);
digitalWrite(motorPin3, LOW);
digitalWrite(motorPin2, LOW);
digitalWrite(motorPin1, HIGH);
delay(motorSpeed);
}
void angle2step(float angle){
Serial.println(angle);
int steps = round(angle * (resolution_stepper2/8/360)); //this line converts the angle required into number of steps.
//resolution_stepper is divided by 8 because of the functions clockwise and counterclockwise
if (angle < 0.0)
{
for (int i=0; i < steps; i++){
counterclockwise ();
Serial.println("coutnerclockwise");
}
}
if (angle > 0.0)
{
for (int i=0; i < steps; i++){
clockwise ();
Serial.println("clockwise");
}
}
}
