Programming of stepping motor

The first script presented below is written for controlling our bipolar stepper motor using the Parallax Basic Stamp 2 microcontroller and the Board of education, and is best suited for demonstrating the principle of stepper motor control, however other hardware can be used with appropriate electronic modules. The nema 34stepper motor is assumed to be connected on pins 1 to 4, and 3 buttons, for changing the direction and type of sequence, are employed.

' {$STAMP BS2}
' {$PBASIC 2.5}

pulsetime CON 25 //experiment with this value in ms

buttons PIN 13
button1 PIN 14
button2 PIN 15

driveanddir VAR Nib
sel VAR Bit

driveanddir=0

DO //main loop start

SELECT driveanddir

IF (buttons=0) THEN
sel=0
IF (button1=1) AND (button2=0) THEN
driveanddir=0
ENDIF
ELSEIF (buttons=0) THEN
sel=0
IF (button1=0) AND (button2=1) THEN
driveanddir=1
ENDIF
ELSEIF (buttons=1) THEN
sel=1
IF (button1=0) AND (button2=1) THEN
driveanddir=2
ENDIF
ELSEIF (buttons=1) THEN
sel=1
IF (button1=0) AND (button2=1) THEN
driveanddir=3
ENDIF
ENDIF

CASE 0 //wave drive clockwise
DO
        driveanddir=0
        HIGH 1
        LOW 2
        LOW 3
        LOW 4
        PAUSE pulsetime
        LOW 1
        HIGH 2
        LOW 3
        LOW 4
        PAUSE pulsetime
        LOW 1
        LOW 2
        HIGH 3
        LOW 4
        PAUSE pulsetime
        LOW 1
        LOW 2
        LOW 3
        HIGH 4
        PAUSE pulsetime
LOOP UNTIL (button2=1) OR (sel=1)

CASE 1 //wave drive counterclockwise
DO
        driveanddir=1
        LOW 1
        LOW 2
        LOW 3
        HIGH 4
        PAUSE pulsetime
        LOW 1
        LOW 2
        HIGH 3
        LOW 4
        PAUSE pulsetime
        LOW 1
        HIGH 2
        LOW 3
        LOW 4
        PAUSE pulsetime
        HIGH 1
        LOW 2
        LOW 3
        LOW 4
        PAUSE pulsetime
LOOP UNTIL (button1=1) OR (sel=1)

CASE 2 //wave drive clockwise
DO
        driveanddir=2
        HIGH 1
        HIGH 2
        LOW 3
        LOW 4
        PAUSE pulsetime
        LOW 1
        HIGH 2
        HIGH 3
        LOW 4
        PAUSE pulsetime
        LOW 1
        LOW 2
        HIGH 3
        HIGH 4
        PAUSE pulsetime
        HIGH 1
        LOW 2
        LOW 3
        HIGH 4
        PAUSE pulsetime
LOOP UNTIL (button2=1) OR (sel=0)

CASE 3 //wave drive counterclockwise
DO
        driveanddir=3
        LOW 1
        LOW 2
        HIGH 3
        HIGH 4
        PAUSE pulsetime
        LOW 1
        HIGH 2
        HIGH 3
        LOW 4
        PAUSE pulsetime
        HIGH 1
        HIGH 2
        LOW 3
        LOW 4
        PAUSE pulsetime
        HIGH 1
        LOW 2
        LOW 3
        HIGH 4
        PAUSE pulsetime
LOOP UNTIL (button1=1) OR (sel=0)
ENDSELECT

Another scripting example, written in C++, for controlling the motor by using the now defunct parallel port is presented below. In this script the nema 42stepper motor is assumed to be connected on physical pins 2 to 5, or bits D0 to D3. A rapid example on how to calculate the output sent to the port:


Bit (pin) D0 (2) D1 (3) D2 (4) D3 (5) D4 (6) D5 (7) D6 (8) D7 (9)
Value (power of 2) 1 2 4 8 16 32 64 128


If you want to set a pin high, i.e. logic output 1, you need to send the corresponding value of the pin to the port. For instance for pin 5 the value to be sent is 8, for pin 3 the value is 2. If multiple pins are required to be set high, the sum of their corresponding values is sent tot the port. As an example, for pins 3 and 4 to be set high simultaneously, the value to be sent is 2+4=6, for pins 5 and 1 to be set high the value is 8+1=9.

#include
#include // ... all required libraries

#define PORT1o 0x378   //lpt output address -- check exact value in your settings
#define PORT1i PORT1o+1 //lpt input address

// ...... removed code used for defining variables and graphics drawing

//---functions defining control sequences for the motor, experiment with the delay value
void action1(void) // ----  wave drive clockwise
{
outportb(PORT1o,0);
outportb(PORT1o,1);
delay(50);
outportb(PORT1o,2);
delay(50);
outportb(PORT1o,4);
delay(50);
outportb(PORT1o,8);
};

void action2(void) // ----  wave drive conterclockwise
{
outportb(PORT1o,0);
outportb(PORT1o,8);
delay(500);
outportb(PORT1o,4);
delay(500);
outportb(PORT1o,2);
delay(500);
outportb(PORT1o,1);
};

void action3(void) // ----  full step clockwise
{
outportb(PORT1o,0);
outportb(PORT1o,3);
delay(500);
outportb(PORT1o,6);
delay(500);
outportb(PORT1o,12);
delay(500);
outportb(PORT1o,9);
};

void action4(void) // ----  full step counterclockwise
{
outportb(PORT1o,0);
outportb(PORT1o,9);
delay(500);
outportb(PORT1o,12);
delay(500);
outportb(PORT1o,6);
delay(500);
outportb(PORT1o,3);
};

// .... removed code

void main(void)  // main program loop

{
// ... removed code
}


The parallel port in brief
In a few words, the parallel port was initially designed for connecting printers to a computer but using it as a general I/O port for communicating with various other devices was pretty straight-forward, especially since IEEE 1284 standard defined the bidirectional implementation of the port. A variety of USB-to-parallel adapters are still available, a selection can be found here.

Parallel port DB-25 connector pinout

• The data register is located at IOBaseAddress+0 (e.g. 0x378, if the LPT port address is 0x378);
• The status register is located at IOBaseAddress+1 (e.g. 0x379) and can be accessed only through read operations;
• The control register is located at IOBaseAddress+2 (e.g. 0x37a) and can be accessed either through write or read operations.

The lines are bidirectional and bits 4 and 5 are for internal control of the parallel interface, bit 4 validates interrupts and bit 5 validates data register input.

See more:
http://forum.cncprovn.com/threads/3967-CKD-Suu-tam-Arduino-closed-loop-Stepper-motor?p=151859

https://forum.vellemanprojects.eu/t/how-to-calculate-linear-motion-mm-with-a-stepper-motor/9660