Arduino Sherline Rotary Table controller

[fiddle561]

i used a Serial I2C 1602 16×2 Character LCD Module it sits on the back of the display. it frees up pins for the keypad.
[URL=".geeetech.com/wiki/index.php/Serial_I2C_1602_16×2_Character_LCD_Module" i went to a 4x20 display and a arduino nano for space.

[liquidhandwash]

thanks, Ive ordered an I2c 4x20, I just was sure about which pin numbers on the arduino to hook it up to

[Marquant]

Hello Sloucks,
I finally managed to get the electronics into function after a lot of trial and errors in the sketch. Now I'am running into the following problems:
The stepperdriver chip (DRV 8825) becomes very hot in a short time even with the heatsink in place and I expected, when dividing a 360° circle into a number of divisions, that the stepper finishes at the same spot as where it started, but that is certainly not the case. I did the test with 2 different steppers: a 12 V 2,5 A - 1,8° / step and a 12 V 1,7 A - 0.9° / step. I altered the corresponding lines in the sketch accordingly of course. I also had to alter the stepdelay, otherwise there was no movement at all. No load was attached to the steppers.
I hope that someone can give me a hint where to find a solution to this problem.
Marquant.

[liquidhandwash]

You should be able to reduce the current by turning the pot on the driver. If they overheat they with go into thermal cutout and lose steps so f you fit the excessive current draw it may fix the your other problem.

[Marquant]

Thanks,
I will give it a try. At the polulu site there is aninstruction on how to set the current on the driver.

[HighDesert]

I like the keypad integration in the OP's design. We built one a year or so ago using a cheap TB6560 driver and push buttons for input, based on a sketch found online somewhere (maybe on this board). It worked well and we discussed modifying the sketch to use a keypad, but I never got around to it. I think I'll try to incorporate the OP's sketch and maybe a different driver (Polulu or EasyDriver from Sparkfun).

[liquidhandwash]

Hi Slouks, Just want to ask about this part of the code

const int StepsPerRotation = 400; //Set Steps per rotation of stepper
const int TableRatio = 72; //ratio of rotary table
const int Multiplier = (StepsPerRotation * TableRatio)/360;

When i change the Table ratio to 140 (or any number above 90) the stepper barely moves.. I change it back to 70 or 80 and it works correctly. It has me a bit stumped it there any thing else i need to do to get a table ratio of 140? Also dropping or increasing the steps per rotation, does something similar. any ideas?

[daniellyall]

how many steps are need to turn you rotary table 399.9

[liquidhandwash]

The table has a ratio of 140, and the steeper driver requires 400 steps per rotation so 56000 steps

[daniellyall]

what motor is it

[liquidhandwash]

it a nema 17 200 steps per rotation.

[MOTOCONA]

GOOD EVENING.
CAN I USE ARDUINO UNO?
GRATEFUL

[squirrel_41]

adruino int can only hold a number up to 32000
so 140 * 400 = 56000 // this will not work also when divided by 360 will yield a Floating point number
I haven't tested but you could try
Float Multiplier = Float(StepsPerRotation * TableRatio)/360

the result = 155.5555

so you could do ((14 * 40)/360) * 100 will get the same result without going over 32000

[jfong]

adruino int can only hold a number up to 32000
so 140 * 400 = 56000 // this will not work also when divided by 360 will yield a Floating point number
I haven't tested but you could try
Float Multiplier = Float(StepsPerRotation * TableRatio)/360

the result = 155.5555

so you could do ((14 * 40)/360) * 100 will get the same result without going over 32000

Arduino compiler can do long 32 bit integers.

https://www.arduino.cc/en/Reference/Long

[squirrel_41]

True but now he should know why it's not working

[liquidhandwash]

Thank you I will give it a try

[mardus]

It will be useful a jog function in order to set a start position. Dividing head has a worm gear so it is difficult to set start position by hand.

[Rich Carlstedt]

Newbie to Arduino here.

How do you change speed ? ( change pulse rate without reprogramming )
If you can slow down the motor when jogging, that would allow reaching a home position much easier...assuming you can stop ?
In industrial machines, jogging stops when the button is released.
No offense guys, I realize this is not a commercially made controller and not all functions are available.
Rich

[jbsorocaba]

Hi all
I made my project with arduio motor shield R3 instead of pololu, but the stepper dont run...Any idea about sketch or libray..?
Tks

[pallikas]

I corrected the above sketch to fix syntax issues with all the LCD Print Commands, that caused it to fail on Arduino 1.6.13. :


/*
A program for controlling a single stepper motor driving a rotary table.
Uses a 4x4 matrix keypad for entry of degrees and direction to move the table.
Serial I2C display, Pololu stepper driver.
*/


#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>

const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
{'1','2','3','A'},
{'4','5','6','B'},
{'7','8','9','C'},
{'.','0','#','D'}
};

byte rowPINS[ROWS] = {11,10,9,8};
byte colPINS[COLS] = {7,6,5,4};

Keypad kpd = Keypad(makeKeymap(keys),rowPINS,colPINS, ROWS, COLS);

LiquidCrystal_I2C lcd(0x27,20,4); // set the LCD address to 0x20 for a 16 chars and 2 line display

//setup vars
const int stp = 12; //connect pin 12 to step
const int dir = 13; // connect pin 13 to dir
const int StepsPerRotation = 400; //Set Steps per rotation of stepper
const int TableRatio = 72; //ratio of rotary table
const int Multiplier = (StepsPerRotation * TableRatio)/360;
const int stepdelay = 1;
float Degrees = 0; //Degrees from Serial input
float ToMove = 0; //Steps to move
int Direction;
int repeat = 0;



void setup()
{
lcd.init(); // initialize the lcd
pinMode(stp, OUTPUT);
pinMode(dir, OUTPUT);

// Print welcome message to the LCD.
lcd.backlight();
lcd.print("Rotarye Control");
lcd.setCursor(0,2);
lcd.print(" CrankyTechGuy CNC");
lcd.setCursor(0,3);
lcd.print(" Copyright 2014");
delay(2000);
lcd.init();
}

void rotation(float tm, int d)
{
if(d == 0)
{
digitalWrite(dir, LOW);
}
else
{
digitalWrite(dir, HIGH);
}

for(int i = 0; i < tm; i++)
{
digitalWrite(stp, HIGH);
delay(stepdelay);
digitalWrite(stp, LOW);
delay(stepdelay);
}
}

float GetNumber()
{
float num = 0.00;
float decimal = 0.00;
float decnum = 0.00;
int counter = 0;
char key = kpd.getKey();
lcd.print("Rotarye Control");
lcd.setCursor(0,2);lcd.print("Enterees then");lcd.setCursor(0,3);lcd.print("press");
lcd.setCursor(8,1);
bool decOffset = false;

while(key != '#')
{
switch (key)
{
case NO_KEY:
break;

case '.':
if(!decOffset)
{
decOffset = true;
}
lcd.print(key);
break;

case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
if(!decOffset)
{
num = num * 10 + (key - '0');
lcd.print(key);
}
else if((decOffset) && (counter <= 1))
{
num = num * 10 + (key - '0');
lcd.print(key);
counter++;
}
break;
}
decnum = num / pow(10, counter);
key = kpd.getKey();
}
return decnum;
}

int GetDirection()
{
int dir = 0;
lcd.setCursor(0,2);lcd.print(" ");

lcd.setCursor(0,3);
lcd.print(" FWD[A] REV[B]");
while(dir == 0)
{
char key = kpd.getKey();
if(key == 'A')
{
dir = 1;
}
else if(key == 'B')
{
dir = -1;
}
}

lcd.clear();
return dir;
}

void loop()
{
if(repeat == 0)
{
Degrees = GetNumber();
Direction = GetDirection();
}

Degrees = Degrees * Direction;

if(Degrees < 0)
{
ToMove = (Degrees*Multiplier)*-1;
lcd.setCursor(0,0);
lcd.print("REV lcd.print(abs(Degrees),2);lcd.print((char)223)");
lcd.setCursor(6,1);
lcd.print("Moving rotation(ToMove,0)");
lcd.setCursor(6,1);
lcd.print(" ");
}
else
{
ToMove = Degrees*Multiplier;
lcd.setCursor(0,0);
lcd.print("FWD lcd.print(Degrees,2);lcd.print((char)223)");
lcd.setCursor(6,1);
lcd.print("Moving rotation(ToMove,1)");
lcd.setCursor(6,1);
lcd.print(" ");
}
lcd.setCursor(0,2);
lcd.print("Repeatancel[B]");
char key = kpd.getKey();
while(key != 'B')
{
key = kpd.getKey();
if(key == 'A')
{
if(Degrees < 0)
{
ToMove = (Degrees*Multiplier)*-1;
lcd.setCursor(6,1);
lcd.print("Moving rotation(ToMove,0)");
lcd.setCursor(6,1);
lcd.print(" ");
}
else
{
ToMove = Degrees*Multiplier;
lcd.setCursor(6,1);
lcd.print("Moving rotation(ToMove,1)");
lcd.setCursor(6,1);
lcd.print(" ");
}
}
}
lcd.clear();

}