Μέτρηση ταχύτητας ήχου με ESP32

 

#include <LiquidCrystal_I2C.h>

#include "BluetoothSerial.h"

BluetoothSerial SerialBT;

// set the LCD number of columns and rows

int lcdColumns = 16;

int lcdRows = 2;

// set LCD address, number of columns and rows

// if you don't know your display address, run an I2C scanner sketch

LiquidCrystal_I2C lcd(0x27, lcdColumns, lcdRows);  

int trig = 5;

int echo = 18;

float sp;

float lecture_echo;

float ds;

String output;

void setup()

{

  SerialBT.begin("ESP32-Bluetooth20250402D");

pinMode(trig, OUTPUT);

digitalWrite(trig, LOW);

pinMode(echo, INPUT);

Serial.begin(115200);

// initialize LCD

  lcd.init();

  // turn on LCD backlight                      

  lcd.backlight();

}

void loop()

{

if(SerialBT.available()) {

  output=SerialBT.readString();

 ds = output.toFloat();

 

 // output = Serial.readString();

 // Serial.println(output);

//  ds = output.toFloat();

Serial.println(ds);

digitalWrite(trig, HIGH);

delayMicroseconds(10);

digitalWrite(trig, LOW);

lecture_echo = pulseIn(echo, HIGH);

sp = ((ds/100) / (lecture_echo/1000000)) * 2;

Serial.print("Speed: ");

Serial.println(sp);

// set cursor to first column, first row

  lcd.setCursor(0, 0);

  // print message

  lcd.print("SpeedOfSound=");

  delay(1000);

  // clears the display to print new message

 // lcd.clear();

  // set cursor to first column, second row

  lcd.setCursor(0,1);

    lcd.print(sp);

  delay(1000);

  lcd.clear();

delay(1000);

}

}