Integrating 4 Endstops into Code that lets 2 Stepper motors drive with a CNC Shi

Projects General Guidance
1

Hello Community,

I am building up a module comparable to a H-Bot, but rather simple. There is just one stepper motor running for the x-Axis and another for y.

This is how I want to just let the belt drive drive around a sensor stopping every few centimeters to let the sensor measure at each point.

I have already put together a sketch that works:

#define EN 8

//Direction pin
#define X_DIR 5
#define Y_DIR 6

//Step pin
#define X_STP 2
#define Y_STP 3

#define MOTOR_X_ENABLE_PIN 8
#define MOTOR_X_STEP_PIN 2
#define MOTOR_X_DIR_PIN 5

#define MOTOR_Y_ENABLE_PIN 8
#define MOTOR_Y_STEP_PIN 3
#define MOTOR_Y_DIR_PIN 6

#define endstop_x1 9
#define endstop_y1 10

//DRV8825
int delayTime=300; //Delay between each pause (uS)
int stps=6400;// Steps to move

void step(boolean dir, byte dirPin, byte stepperPin, int steps)

{

digitalWrite(dirPin, dir);

delay(100);

for (int i = 0; i < steps; i++) {

digitalWrite(stepperPin, HIGH);

delayMicroseconds(delayTime);

digitalWrite(stepperPin, LOW);

delayMicroseconds(delayTime);

}

}

void setup(){

pinMode(X_DIR, OUTPUT); pinMode(X_STP, OUTPUT);

pinMode(Y_DIR, OUTPUT); pinMode(Y_STP, OUTPUT);

pinMode(EN, OUTPUT);

digitalWrite(EN, LOW);

}

void loop(){

step(true, X_DIR, X_STP, stps); //X, Counterclockwise

delay(1000);

step(true, X_DIR, X_STP, stps); //X, Counterclockwise

delay(1000);

step(true, X_DIR, X_STP, stps); //X, Counterclockwise

delay(1000);

step(true, X_DIR, X_STP, stps); //X, Counterclockwise

delay(1000);

step(true, X_DIR, X_STP, stps); //X, Counterclockwise

delay(1000);

step(false, Y_DIR, Y_STP, stps); //Y, Clockwise

delay(1000);

step(false, X_DIR, X_STP, stps); //X, Clockwise

delay(1000);

}

The only problem now is that I want to integrate 4 Endstoppers to the CNC Shield. The next step would be now to instead of following a certain route, the sensor should follow the x-axis in one direction until a end stop is reached. Then it should move one step on the y-axis and start on the x-axis again in the other direction until it reaches an endstop again.

In the code I just want to have it like this:

step(true, X_DIR, X_STP, stps); //X, Counterclockwise

if Endstop is hitted
step (false, Y-DIR, Y_STP, stps)
step false, X_DIR, X_STP, stps)

I have looked up a couple of possibilities, but I couldnt find any apropriate solution to include the Endstops into the Arduino sketch so far. Can you assist me somehow? I imagined it to be not that hard, but if anyone has some experiences with endstops it might be solved rather quickly. Thanks in advance!

2

Please modify your Post and use the Code button </> rather than the Quote button for your code.

If you want to detect an end-stop then you MUST use non-blocking code so that the stop-switch can be checked between every step. The functions delay() and delayMicroseconds() block the Arduino until they complete.
Have a look at how millis() is used to manage timing without blocking in Several Things at a Time.

And see Using millis() for timing. A beginners guide if you need more explanation.

The code in the second example in this Simple Stepper Code is non-blocking.

You may find that using the non-blocking run() or runSpeed() functions of the AccelStepper library make life easier.

...R
Stepper Motor Basics

3

Before each step, check the limit switch. If you want 4 separate endstops you will have to assign two more input pins.

const byte MOTOR_ENABLE_PIN = 8;


const byte MOTOR_X_STEP_PIN  = 2;
const byte MOTOR_X_DIR_PIN = 5;


const byte MOTOR_Y_STEP_PIN = 3;
const byte MOTOR_Y_DIR_PIN = 6;


const byte endstop_x1 = 9;
const byte endstop_y1 = 10;


//DRV8825
coinst int delayTime = 300; //Delay between each pause (uS)
int stps = 6400; // Steps to move


void stepX(int steps)
{
  byte limitPin;


  if (steps < 0)
  {
    digitalWrite(MOTOR_X_DIR_PIN, LOW);
    limitPin = endstop_x1;
    steps = -steps;
  }
  else
  {
    digitalWrite(MOTOR_X_DIR_PIN, HIGH);
    limitPin = endstop_x1;
  }


  for (int i = 0; i < steps; i++)
  {
    if (digitalRead(limitPin) == LOW)
      return;  // Already hit the limit switch
    digitalWrite(MOTOR_X_STEP_PIN, HIGH);
    delayMicroseconds(delayTime);
    digitalWrite(MOTOR_X_STEP_PIN, LOW);
    delayMicroseconds(delayTime);
  }
}


void stepY(int steps)
{
  byte limitPin;


  if (steps < 0)
  {
    digitalWrite(MOTOR_Y_DIR_PIN, LOW);
    limitPin = endstop_y1;
    steps = -steps;
  }
  else
  {
    digitalWrite(MOTOR_Y_DIR_PIN, HIGH);
    limitPin = endstop_y1;
  }


  for (int i = 0; i < steps; i++)
  {
    if (digitalRead(limitPin) == LOW)
      return;  // Already hit the limit switch
    digitalWrite(MOTOR_Y_STEP_PIN, HIGH);
    delayMicroseconds(delayTime);
    digitalWrite(MOTOR_Y_STEP_PIN, LOW);
    delayMicroseconds(delayTime);
  }
}


void setup()
{
  pinMode(MOTOR_X_DIR_PIN, OUTPUT);
  pinMode(MOTOR_X_STEP_PIN, OUTPUT);
  pinMode(endstop_x1, INPUT_PULLUP);


  pinMode(MOTOR_Y_DIR_PIN, OUTPUT);
  pinMode(MOTOR_Y_STEP_PIN, OUTPUT);
  pinMode(endstop_y1, INPUT_PULLUP);




  pinMode(MOTOR_ENABLE_PIN, OUTPUT);
  digitalWrite(MOTOR_ENABLE_PIN, LOW);
}


void loop()
{
  stepX(-stps); //X, Counterclockwise
  delay(1000);
  stepX(-stps); //X, Counterclockwise
  delay(1000);
  stepX(-stps); //X, Counterclockwise
  delay(1000);
  stepX(-stps); //X, Counterclockwise
  delay(1000);
  stepX(-stps); //X, Counterclockwise
  delay(1000);
  stepY(stps); //Y, Clockwise
  delay(1000);
  stepX(stps); //X, Clockwise
  delay(1000);
}
4

Wow thank you so much this is working just perfetly!

I didn't expect the solution coming so quick :smiley: