On this page, I document my process of and research on controlling the movement of motors with light sensors.

COMPONENTS I CAN USE

Servo motors

analog clock making with servo motors: https://electronics-project-hub.com/analog-clock-using-arduino/

NOTES ON SERVO MOTORS

Can only rotate 180 degrees
Controlled by a PWM signal
Consists of a complex gear mechanism, a DC motor and a controller with feedback system
- gears will educe the speed of rotation t the output but it increases the torque which we want from a servo monitor
has 3 pins:
- red is +5V
- brown is -Ve
- orange is PWM input

previous work with it documented: https://app.archbee.com/docs/hac8usg8LteFu7mWCOJMo/3i1QbF-wiJoXSA8UivstD

Stepper motors

Stepper motor basics: https://forum.arduino.cc/t/stepper-motor-basics/275223 (not applied to unipolar steppers)

JK42HS40-1704-83AF

Data sheet : https://datasheetspdf.com/pdf/1380131/ETC/JK42HS/1

Someone working with the same and trying to find driver : https://forum.arduino.cc/t/stepper-driver-to-this-stepper-motor/299923

bipolar
200 steps per revolution
1700 m/A per coil
2.7 v

possible drivers:

A4988
DRV8825
DRV8824

28BYJ-48

Data sheet : https://www.digikey.nl/en/datasheets/mikroelektronika/mikroelektronika-step-motor-5v-28byj48-datasheet

unipolar (6 wires)
compatible with driver ULN2003
32 steps per revolution

NOTES ON STEPPER MOTORS

Broadly speaking there are two types of stepper motors: UNIPOLAR AND BIPOLAR

Unipolar:

four wires connecting to the two separate coils inside the motor (one pair to each coil)

Bipolar:

Two types; with 5 wires and with 6 (hybrid) wires

Light sensor

Light sensor LM393 9AM

same as : https://www.reichelt.nl/nl/nl/ontwikkelaarspanelen-lichtsensor-met-hoog-laag-rendement-lm39-debo-light-sens-p224222.html?PROVID=2809&gclid=Cj0KCQjw8qmhBhClARIsANAtbod-Ijv9C5QOjDjeGF2yvb9s8kTvQ6j2YI7AcJXzKBBsFdreawby7PgaAqCsEALw_wcB

https://www.instructables.com/LDR-Sensor-Module-Users-Manual-V10/

Light sensor TEMT 60000

same as : https://www.tinytronics.nl/shop/en/sensors/optical/light-and-color/temt6000-light-sensor-module

Stepper motor to Arduino

connecting Stepper motor 28BYJ-48 and driver ULN2003 to Arduino UNO

code: https://soldered.com/learn/how-to-use-stepper-motor-and-uln2003-driver/

/*
*  BYJ48 Stepper motor with the ULN breakout board
*  Connect :
*  IN1 - D8
*  IN2 - D9
*  IN3 - D10
*  IN4 - D11
*  VCC - 5V
*  Gnd - gnd
* 
*  e-radionica.com
*/
#define IN1  8
#define IN2  9
#define IN3  10
#define IN4  11
int koraci = 0;
boolean smjer = true;
unsigned long vrijemeZadnje = 0;    // we will note the time
unsigned long vrijemeTrenutno = 0;  // needed to
unsigned long vrijeme = 0;          // execute the given angle
int koraciPreostalo = 4095; //this stepper has 4095 steps in total
void setup()
{
    Serial.begin(115200);
    pinMode(IN1, OUTPUT);
    pinMode(IN2, OUTPUT);
    pinMode(IN3, OUTPUT);
    pinMode(IN4, OUTPUT);
}
void loop()
{
  while(koraciPreostalo > 0) // steps remaining until the full circle
  {
    vrijemeTrenutno = micros(); //write down the current time in microseconds
    if(vrijemeTrenutno - vrijemeZadnje >= 1000)
    {
      stepper(1); //call the stepper function (check void stepper below)
      vrijeme = vrijeme + micros() - vrijemeZadnje;
      vrijemeZadnje = micros();
      koraciPreostalo--;
    }
   }
   
   Serial.println(vrijeme);
   Serial.println("Wait..!");
   delay(2000);
   smjer = !smjer; // opposite direction
   koraciPreostalo = 4095;  // reset the number of steps
}
void stepper(int brojKoraka)
{
  for (int x=0; x < brojKoraka; x++) { switch(koraci) { case 0: digitalWrite(IN1, LOW); digitalWrite(IN2, LOW); digitalWrite(IN3, LOW); digitalWrite(IN4, HIGH); break; case 1: digitalWrite(IN1, LOW); digitalWrite(IN2, LOW); digitalWrite(IN3, HIGH); digitalWrite(IN4, HIGH); break; case 2: digitalWrite(IN1, LOW); digitalWrite(IN2, LOW); digitalWrite(IN3, HIGH); digitalWrite(IN4, LOW); break; case 3: digitalWrite(IN1, LOW); digitalWrite(IN2, HIGH); digitalWrite(IN3, HIGH); digitalWrite(IN4, LOW); break; case 4: digitalWrite(IN1, LOW); digitalWrite(IN2, HIGH); digitalWrite(IN3, LOW); digitalWrite(IN4, LOW); break; case 5: digitalWrite(IN1, HIGH); digitalWrite(IN2, HIGH); digitalWrite(IN3, LOW); digitalWrite(IN4, LOW); break; case 6: digitalWrite(IN1, HIGH); digitalWrite(IN2, LOW); digitalWrite(IN3, LOW); digitalWrite(IN4, LOW); break; case 7: digitalWrite(IN1, HIGH); digitalWrite(IN2, LOW); digitalWrite(IN3, LOW); digitalWrite(IN4, HIGH); break; default: digitalWrite(IN1, LOW); digitalWrite(IN2, LOW); digitalWrite(IN3, LOW); digitalWrite(IN4, LOW); break; } postaviSmjer(); } } void postaviSmjer() { if(smjer==1){ koraci++; } if(smjer==0){ koraci--; } if(koraci>7){ koraci=0; }
    if(koraci<0){ koraci=7; }
}

(video of code running with 1 tooth gear)

On how I made this gear, see my gear production page

Light sensor reading serial monitor

https://www.hackster.io/kiranpaul/light-magic-using-lm393-and-arduino-uno-14eadc

giving digital input

void setup() {
  pinMode(7,INPUT);
  /*pinMode(9,OUTPUT); */
  Serial.begin(9600); //initialise serial monitor

}

void loop() {
  int temp=digitalRead(8);      //assign value of LDR sensor to a temporary variable
  Serial.println("Intensity="); //print on serial monitor using ""
  Serial.println(temp);         //display output on serial monitor
  delay(300);
  if(temp==HIGH)               //HIGH means,light got blocked
  digitalWrite(9,HIGH);        //if light is not present,LED on
  else
  digitalWrite(9,LOW);         //if light is present,LED off
}

Light sensor and stepper motor

// Arduino stepper motor and LDR
// based on https://www.instructables.com/Light-Sensor-Stepper-Motor-Arduino/ but with some modifications
#include <Stepper.h>

// Include the header file

// change this to the number of steps on your motor

#define STEPS 32

// create an instance of the stepper class using the steps and pins

Stepper stepper(STEPS, 8, 10, 9, 11);

int val = 0;

int LDR = 7;

void setup()

{

Serial.begin(9600);

stepper.setSpeed(200);

pinMode(LDR, INPUT);

}

void loop()

{

int LDRValue = digitalRead(LDR);

Serial.print("sensor = ");

if (LDRValue ==LOW)

{

val = Serial.parseInt();

stepper.step(512);

Serial.println(val);

//for debugging

}

else

{

//digitalWrite(LED, LOW);

}

}

1 tooth gear with light sensor (video of gear running when light is detected, and stops once all light is blocked)

On how I made this gear, see my gear production page

ASSEMBLY:

Stepper 28YJ-48 5 wires to Driver ULN2003

Driver ULN2003 to Arduino UNO

Int1 to pin D8

Int2 to pin D9

Int3 to pin D10

Int4 to pin D11

Ground to pin Ground

Power to pin 5V

LM393 9AM sensor to Arduino UNO

VCC to pin 5V

GROUND to pin Ground

DO to D7

Ella Suzanne

Documentation site as intern at Fablab in Waag, Amsterdam