ESP32 Laser Indicator Ranging Box

Purpose:

Ultrasonic sensors measure distance by sending and receiving the ultrasonic wave and use Laser module 5mW 650nm to indicate the object then show the distance value on LCD module.

利用ESP32做一個雷射對標然後在HC-SR04 ultrasonic sensor模組的範圍內去measure物體所在的距離並且顯示距離在LCD面板上.

Use ESP32 to make a laser benchmark and then measure the distance of the object within the range of the HC-SR04 ultrasonic sensor module and display the distance on the LCD panel.

BOM(Bill of Material):

HC-SR04 ultrasonic sensor

Laser module 5mW 650nm:

ESP32 module

LCD module

Circuit:

Pin Definition:

YouTube Demo:

Code Introduce:

#include <LiquidCrystal.h>

//---LCD -----------

//LiquidCrystal_I2C LCD = LiquidCrystal_I2C(0x27, 16, 2);

LiquidCrystal LCD(22,23,5,18,19,21);

//------LED------------------

#define LED_BUILTIN 2

//-----switch------------------

#define MODE_PIN    27

#define LASER_PIN   26

//-----hcsr04 sensor------------------

#define TRIGPIN_PIN  12

#define ECHO_PIN    14

long duration;

int distance;

unsigned long currentMillis = 0;

unsigned long previousMillis = 0;

//--------- Flag structure --------------------------------------

typedef struct _vFlag

{

  uint8_t HCSR04Flag = 0;

  uint8_t LEDFlag = 1;

} vFlag;

vFlag *flag_Ptr;

vFlag flag;

//-------------------------------------------------

void setup()

{

  Serial.begin(9600);

  Serial.println(F("init"));

  pinMode(LED_BUILTIN, OUTPUT);

  pinMode(TRIGPIN_PIN, OUTPUT);

  pinMode(ECHO_PIN, INPUT);

  pinMode(LASER_PIN, OUTPUT);

  pinMode(MODE_PIN, INPUT_PULLUP);

  LCD.begin(20, 2);

  LCD.clear();

  LCD.setCursor(0, 0);

  LCD.print("Distance (cm) ");

  spinner();

  LCD.setCursor(0, 1);

  LCD.print("------------- ");

}

//-----------------------------------------

void loop()

{

  Serial.print(F("Main at core:"));

  Serial.println(xPortGetCoreID());

  while(1)

  {

    if(flag.LEDFlag == 1)

    {

      digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level)

      vTaskDelay(300);

      spinner();

      digitalWrite(LED_BUILTIN, LOW); // turn the LED off by making the voltage LOW

      vTaskDelay(300);

    }

    if ((digitalRead(MODE_PIN) == LOW))

    {

      flag.HCSR04Flag = 1;

      flag.LEDFlag = 0;

      digitalWrite(LASER_PIN, HIGH);      

    }

    else if((digitalRead(MODE_PIN) == HIGH))

    {

      flag.HCSR04Flag = 0;

      flag.LEDFlag =1;

      digitalWrite(LASER_PIN, LOW);

      LCD.clear();

      LCD.setCursor(0, 0);

      LCD.print("Distance (cm) ");

      //spinner();

      LCD.setCursor(0, 1);

      LCD.print("------------- ");

    }

   

    if(flag.HCSR04Flag==1)

    {

      currentMillis = millis();

     

      pinMode(TRIGPIN_PIN, OUTPUT);

      digitalWrite(TRIGPIN_PIN, LOW);  //關閉超音波

      delayMicroseconds(2);  //sustain at least 10us HIGH pulse

      digitalWrite(TRIGPIN_PIN, HIGH); //啟動超音波

      delayMicroseconds(10);  //sustain at least 10us HIGH pulse

      digitalWrite(TRIGPIN_PIN, LOW);  //關閉超音波

      pinMode(ECHO_PIN, INPUT);

      duration= pulseIn(ECHO_PIN, HIGH);

      distance= duration/29/2;

      if (duration==0)

      {

        Serial.println("No pulse is from sensor");

      }

      else {

        Serial.print("Ultrasonic sensor is shown distance:");

        Serial.print(distance);

        Serial.println("cm");

        LCD.clear();

        LCD.setCursor(0, 0);

        LCD.print("Distance (cm) ");

        spinner();

        LCD.setCursor(0, 1);

        LCD.print(distance);

      }

    }

  }

}

//----------------------------------------------

void spinner()

{

  static int8_t counter = 0;

  const char* glyphs = "\xa1\xa5\xdb";

  LCD.setCursor(15, 0);

  LCD.print(glyphs[counter++]);

  if (counter == strlen(glyphs)) {

    counter = 0;

  }

}

//-----------------------------------------