L297/L298 + Step Motor + LDRs - Arduino Solar Tracker

Projects General Guidance
1

Hi everybody...
I'm here to get some advices and help to finish my college final course project... It's a Arduino Solar Tracker for a small dimension solar panel using LDR sensors.

You can check the video of the L297/L298/L6210 test:

The actual code that I'm usign:

#define NAME "SOLAR TRACKER"
#define VERSION "0.1"


//ANALOGIC PINS
int pinLdr_1 = 3;
int pinLdr_2 = 4;
int pinLdr_3 = 5;

// ENABLE, HALF-FULL, CW-CCW, CLK  - TO L297
int pinEnable = 2;
int pinCwCCW = 4;
int pinCLK = 5;

int ldr1 = 0;
int ldr2 = 0;
int ldr3 = 0;

void setup(){
  Serial.begin(9600);
  pinMode(pinEnable, OUTPUT);
  pinMode(pinCwCCW, OUTPUT);
  pinMode(pinCLK, OUTPUT);
}

void steps(int nro){
  int i;
  for(i=0;i<nro;i++){
    digitalWrite(pinCLK,LOW);
    digitalWrite(pinCLK,HIGH);
    delayMicroseconds(2000);
  }
}

void loop(){
  //tone(pinCLK,50); //100Hz -> gerador de onda
    
  ldr1 = analogRead(pinLdr_1);
  ldr2 = analogRead(pinLdr_2);
  ldr3 = analogRead(pinLdr_3);

  delay(1000);

  //ldr1 - right
  //ldr2 - middle
  //ldr3 - left
  
  if ((ldr1 > ldr2) && (ldr1>ldr3)){
    //move right
        digitalWrite(pinCwCCW,LOW);
        digitalWrite(pinEnable,HIGH);
        steps(1000);
        digitalWrite(pinEnable,LOW);
  } else if ((ldr3 > ldr2) && (ldr3>ldr1)){
    //move left
       digitalWrite(pinCwCCW,HIGH);
       digitalWrite(pinEnable,HIGH);
       steps(1000);
       digitalWrite(pinEnable,LOW);
  } else {
    digitalWrite(pinEnable,LOW);
  }
  
  
  
}

The problems that I'm having:

  • What's the better way to read the LDR sensors and compare then to take decisions (because of the LDR delay) ***

  • As I'm doing a solar tracker, I don't need fast response, so how can I make a function to send 4 steps for example to L297 ? The actual function "steps" I based on EasyDriver example... ***

  • I was using the tone() function to send CLOCK signal to L297 but it was too fast to move the panel and on changing the rotation (clockwise/counter-clockwise) the motor stucks...

The LDRs

Arduino Uno at Work

Any suggestions or advices to improve my code ?

2

The problems that I'm having:

  • What's the better way to read the LDR sensors and compare then to take decisions (because of the LDR delay) ***

Just how fast does the sun move in your part of the world? Checking every 5 minutes should be plenty often.

On the other hand,

  ldr1 = analogRead(pinLdr_1);
  ldr2 = analogRead(pinLdr_2);
  ldr3 = analogRead(pinLdr_3);

  delay(1000);

You really can't complain about how long the LDR reading takes...