Stepper Motor - Serial. How to rotate CCW?

Projects Programming
1

Hello, I have the code below:

Basically when i type the number into serial monitor it will rotate the stepper motor "X" degrees.
At the moment, if i type 100 in serial monitor it will rotate 100 degrees forward.
but when i type -100 it wont turn it 100 degrees backwards.

Any Suggestions, I have tried Stepper Library and it seemed to have a mind of its own.

<//define pin numbers
#define IN1 8
#define IN2 9
#define IN3 10
#define IN4 11

int ang = 0;
//for the delay
int mils = 1;

void setup() {

pinMode(IN1, OUTPUT);
pinMode(IN2, OUTPUT);
pinMode(IN3, OUTPUT);
pinMode(IN4, OUTPUT);
Serial.begin(9600);

}

void loop() {
// Read input from serial Monitor if available
if (Serial.available()) {
ang = Serial.parseInt();
Serial.println("Read " + String(ang) + " degrees");
rotate(ang);
}

}

void rotate(int angle)
{
int numberOfRounds = (int) angle * 1.42222; // angle*512/360
for (int i = 0; i < numberOfRounds; i++) {

//1000
digitalWrite(IN1, HIGH);
digitalWrite(IN2, LOW);
digitalWrite(IN3, LOW);
digitalWrite(IN4, LOW);
delay(mils);

//1100
digitalWrite(IN1, HIGH);
digitalWrite(IN2, HIGH);
digitalWrite(IN3, LOW);
digitalWrite(IN4, LOW);
delay(mils);

//0100
digitalWrite(IN1, LOW);
digitalWrite(IN2, HIGH);
digitalWrite(IN3, LOW);
digitalWrite(IN4, LOW);
delay(mils);

//0110
digitalWrite(IN1, LOW);
digitalWrite(IN2, HIGH);
digitalWrite(IN3, HIGH);
digitalWrite(IN4, LOW);
delay(mils);

//0011
digitalWrite(IN1, LOW);
digitalWrite(IN2, LOW);
digitalWrite(IN3, HIGH);
digitalWrite(IN4, HIGH);
delay(mils);

//0010
digitalWrite(IN1, LOW);
digitalWrite(IN2, LOW);
digitalWrite(IN3, HIGH);
digitalWrite(IN4, LOW);
delay(mils);

//0001
digitalWrite(IN1, LOW);
digitalWrite(IN2, LOW);
digitalWrite(IN3, LOW);
digitalWrite(IN4, HIGH);
delay(mils);

//1001
digitalWrite(IN1, HIGH);
digitalWrite(IN2, LOW);
digitalWrite(IN3, LOW);
digitalWrite(IN4, HIGH);
delay(mils);

}
// Switch off all phases
digitalWrite(IN1, LOW);
digitalWrite(IN2, LOW);
digitalWrite(IN3, LOW);
digitalWrite(IN4, LOW);
}>

2

No code has a "mind on its own" not even chatGPT

The bug has his hands on the keyboard and is staring at the screen (Yes you yourself)

If a library does not behave like you want you haven't yet fully understood how the library works.
Same thing with rotation counter-clockwise for rotating ccw you have to switch the IOpins in the reversed order.

Again: Knew knowledge makes live easier.
With stepper-motor-drivers like the DRV8825 or TMC2209 you have a simple two wire interface step and direction
change DIR-pin from low to HIGH and the stepper-motor runs the opposite direction by simply creating step-pulses on a single IO-pin.

best regards Stefan

1 Like
3

would you know how to reverse the motor with the current code? without changing the driver board?

4

This is what I use:
FORWARD
write(1, 0, 0, 0);
write(1, 1, 0, 0);
write(0, 1, 0, 0);
write(0, 1, 1, 0);
write(0, 0, 1, 0);
write(0, 0, 1, 1);
write(0, 0, 0, 1);
write(1, 0, 0, 1);

REVERSE
write(0, 0, 0, 1);
write(0, 0, 1, 1);
write(0, 0, 1, 0);
write(0, 1, 1, 0);
write(0, 1, 0, 0);
write(1, 1, 0, 0);
write(1, 0, 0, 0);
write(1, 0, 0, 1);

5

Would you happen to have an example? im still learning code so it takes me ages to figure out without seeing the code.

6

Just take the code you already have to move it forward and use it again in reverse order to make it move in the opposite direction.

Example FORWARD > 1000, 1100, 0100, 0110, 0010, 0011, 0001, 1001
Example REVERSE > 1001, 0001, 0011, 0010, 0110, 0100, 1100, 1000

7

Thank you, ill Try this

8

that is what user @essejcds posted
simply switching the IP-pins in reversed order

9

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