Hi Toni,
In future, make sure you enclose your code in 3 backticks (```) either side. that’ll make it much easier for us to read or copy into an editor. As it stands your PDF doesn’t copy well into the Arduino IDE, it’s missing a lot of the spacing. Here’s what will show up on the right side of the editor if you do it right:
/*
* Stepper Motor Traverser Control (pushbutton and led panel)
* This programme drives a unipolar or bipolar stepper motor for use with a model rai track
traverser.
*
* Created 19 November 2022
* Amended 2 January 2023
* Amended 17 January 2023
*/
// Libraries required
#include<Stepper.h>
// define motor characteristics
const int stepsPerRevolution = 200;
Stepper DMProject(stepsPerRevolution,8,9,10,11);
//const float trackspace = 118.125; // steps between tracks = 5.4/32*700
const float trackspace = 116.25; // steps between tracks = 5.4/32*700
// define arrays and variables
const int ledPin[7] = {22,24,26,28,30,32,34};
const int buttonPin[7] = {50,48,46,44,42,40,38};
const int location[7] = {-3*trackspace,-2*trackspace,-
1*trackspace,0,1*trackspace,2*trackspace,3*trackspace};
int currentbuttonState[7] = {0,0,0,1,0,0,0};
int currentledState[7] = {0,0,0,1,0,0,0};
int nextlocation[7] ={0,0,0,0,0,0,0};
int nextbuttonState[7] = {0,0,0,0,0,0,0};
int nextledState[7] = {0,0,0,0,0,0,0};
int currentlocation = 3;
void setup(){
// initialize the serial port
Serial.begin(9600);
DMProject.setSpeed(20); // recheck in situ
//initialise led and button pins
for (int p=0;p<7;p++)
{
pinMode(ledPin[p], OUTPUT);
pinMode(buttonPin[p], INPUT_PULLUP);
digitalWrite(ledPin[p],0);
}
}
void loop()
{
Serial.println("START LOOP");
int testposition;
int origin = currentlocation;
int b; // location variable (button loop counter)
Serial.print("old currentlocation = ");
Serial.println(currentlocation);
// initialise leds
digitalWrite(ledPin[currentlocation],1);
// initialise arrays
for (int a = 0; a<7; a++)
{
currentbuttonState[a] = 0;
currentledState[a] = 0;
nextbuttonState[a] = 0;
nextledState[a] = 0;
nextlocation[a] = 0;
currentledState[currentlocation] = 1;
}
//Check for activation of button
for ( b=0 ; b<7 ;b++)
{
Serial.print("b = ");
Serial.println(b);
testposition = (digitalRead(buttonPin[b]));
Serial.print("testposition = ");
Serial.println(testposition);
//test if change to button position
if (testposition == 0 ) //&& currentlocation != b)
{
// turn off led
digitalWrite(ledPin[currentlocation],0);
// Amend arrays and variables for next position/situation
currentledState[b] = 1;
currentbuttonState[b] = 1;
nextledState[b] = 0;
nextbuttonState[b] = 0;
nextlocation[b] = 0;
currentlocation = b;
// Serial print new values
Serial.print("b = ");
Serial.println(b);
Serial.print("origin = ");
Serial.println(location[origin]);
Serial.print("neworigin = ");
Serial.println(location[b]);
Serial.print("new currentlocation = ");
Serial.println(location[origin]);
//Ammend pins
digitalWrite(ledPin[b],1);
// step to new location on button state changes
int steps = location[b] - location[origin];
Serial.print("steps = ");
Serial.println(steps);
//delay(3000);
DMProject.step(steps);
}
}
}
Could you explain why the start location is 3? Have you been playing around with the value to get it bang on? If not, that might explain your error,
Typically, systems like yours have a limit switch on one end, which when activated by your moving thing bumping into it, gives your microcontroller an accurate zero.
Have you tried stripping back your project to just movement by a set amount and gradually adding in bits to see if any of your logic breaks it?
Could it be backlash? How much does your table move back and forth with the stepper trying to hold it in a particular position?
How much error are you actually seeing? Have you measured it with calipers and worked out how many steps that is?
