Driving 28BYJ-48-5V Stepper Motor with ULN2003A Transistor Arrays on Arduino

28BYJ-48-5V Stepper Motor နဲ့ ULN2003A driver တွေက တော်တော် အသုံးများပုံရပြီး အလွယ်တကူ ဝယ်နိုင်ရုံတင်မက စျေးလည်း တော်တော်ပေါ ပါတယ်။Stepper Library ကို မသုံးပဲ Arduino ရဲ့ Port B ကို သုံးပြီး Stepper motor ကို ထိန်းတဲ့ ရိုးရှင်းတဲ့ နမူနာလေး ဖော်ပြချင်ပါတယ်။ 

Figure. Driving 28BYJ-48-5V Stepper Motor with Arduino UNO using USB power.

28BYJ-48-5V Stepper Motor က 5V နဲ့ တိုက်ရိုက်မောင်းနိုင်ပြီး၊ unipolar stepper motor အမျိုးအစားပါ။ သူ့ရဲ့ schematic ကို အောက်မှာပြထားပါတယ်။ 

Figure. 28BYJ-48-5V Stepper Motor.

ULN2003A Transistor Arrays ကတော့ inductive load တွေကို drive လုပ်ဖို့ ဒီဇိုင်းလုပ်ထားတာမို့ အထဲမှာ free wheeling diode ပါ ပါ ပါတယ်။ Darlington pair သုံးထားတာမို့ အဝင် ဗို့ 1.4V လောက်ကနေ 30V အထိ ကြိုက်တဲ့ ဗို့နဲ့ တိုက်ရိုက်ဆက်ပြီး ထိန်းနိုင်ပါတယ်။ 

Figure. ULN2003A.

Wave drive, Full step drive နဲ့ Half step drive တွေကို သုံးပြထားတဲ့ နမူနာ ပရိုဂရမ် လေးကို အောက်မှာ ပြထားပါတယ်။ 

Credit to......cool-emerald

//Driving 28BYJ-48-5V Stepper Motor using ULN2003A Transistor Arrays
//Author: Yan Naing Aye
//Website: http://www.cool-emerald.com/

#include "StepperPortB.h"
//----------------------------------------------------------
void setup() {    
  StepperInit();//setup pins
  //StepperMode(WAVE);
  //StepperMode(FULL);
  StepperMode(HALF);
  //Serial.begin(9600);
}
void loop() {
  Step(4096,2500); //turn 4096 steps forward with 2500 us period for each step
  Step(-4096,2500);//turn 4096 steps backward with 2500 us period for each step
  //Serial.println(CS);
}

//File: StepperPortB.h
//Author: Yan Naing Aye
//Website: http://www.cool-emerald.com/

//Driving 28BYJ-48 – 5V Stepper Motor using ULN2003A Transistor Arrays
//----------------------------------------------------------
#ifndef StepperPortB_h
  #define StepperPortB_h
  #include "Arduino.h"
byte* S; //Stepping sequence

//Wave drive
//Step          0 | 1 | 2 | 3 | 0 |...

//Blue   = A :  1 | 0 | 0 | 0 | 1 | ...
//Pink   = B :  0 | 1 | 0 | 0 | 0 | ...
//Yellow = C :  0 | 0 | 1 | 0 | 0 | ...
//Orange = D :  0 | 0 | 0 | 1 | 0 | ...
byte Wave[4] = {0x01,0x02,0x04,0x08};

//Full Step drive
//Step          0 | 1 | 2 | 3 | 0 |...

//Blue   = A :  1 | 1 | 0 | 0 | 1 | ...
//Pink   = B :  0 | 1 | 1 | 0 | 0 | ...
//Yellow = C :  0 | 0 | 1 | 1 | 0 | ...
//Orange = D :  1 | 0 | 0 | 1 | 1 | ...  
byte FullStep[4] = {0x09,0x03,0x06,0x0C};

//Half Step drive
//Step          0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 0 |...

//Blue   = A :  1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 |...
//Pink   = B :  0 | 0 | 1 | 1 | 1 | 0 | 0 | 0 | 0 |...
//Yellow = C :  0 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 0 |...
//Orange = D :  1 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 |...
byte HalfStep[8] = {0x09,0x01,0x03,0x02,0x06,0x04,0x0C,0x08};
int CS=0;//Current step
int N;
//----------------------------------------------------------
//Mode definition
#define HALF 0
#define FULL 1
#define WAVE 2
//Define the mode to drive the stepper motor
void StepperMode(int Mode) {  
  if(Mode==WAVE) {S=Wave; N=4;}
  else if(Mode==FULL) {S=FullStep; N=4;}
  else {S=HalfStep; N=8;}
}
//----------------------------------------------------------
//Turn stepper motor n steps
//with t microseconds period for each step
//positive n for forward dir and negative n for backward dir
void Step(int n,int t) {
  int CD=1; 
  if(n<0) {n*=-1; CD=-1;}
  for(int i=0;i<n;i++) {
    CS=(CS+(N+CD))%N;
    PORTB=S[CS];
    delayMicroseconds(t);
  }
}
//----------------------------------------------------------
//Initialize
void StepperInit() {
  //Setup port B (digital pin 8 to 13)
  //The two high bits (6 & 7) map to the crystal pins and are not usable
  //only 4 pins - 8 to 11 are used in this program
  //where Blue - pin 8 (LSB), Pink -pin 9, Yellow -pin 10, Orange -pin 11
  DDRB=0xff;
  PORTB = 0x00;  
}
//----------------------------------------------------------
#endif