ESP32_IR_Meter

// Reference:
// https://circuitdigest.com/microcontroller-projects/interfacing-flame-sensor-with-arduino
// https://circuitdigest.com/microcontroller-projects/arduino-frequency-counter-circuit
// https://www.instructables.com/Arduino-Frequency-Counter/
// https://github.com/Bodmer/TFT_eSPI/blob/master/examples/160%20x%20128/TFT_Print_Test/TFT_Print_Test.ino

// Uses IR Infrared Flame Sensor Module 4 Pin

#include "Arduino.h"
#include <TFT_eSPI.h> // Graphics and font library for ILI9341 driver chip
#include <SPI.h>

// Pin Assignments
#define IR_Pin 2

// Variables
unsigned long H_cycle;
unsigned long L_cycle;
unsigned long Freq;
char str_Freq[32];
TFT_eSPI tft = TFT_eSPI();  // Invoke TFT library

void setup(){
    // Initalize GPIO pins
    pinMode(IR_Pin, INPUT);

    // Initalize Serial port
    Serial.begin(9600);

    // Initalize TFT
    tft.init();
    tft.setRotation(1);
  tft.fillScreen(TFT_BLACK);
}

void loop (){
    Freq = 0;
  //tft.fillScreen(TFT_BLACK);

    H_cycle = pulseIn(IR_Pin,HIGH); // read signal at high state
  L_cycle = pulseIn(IR_Pin,LOW);    // read signal at low state
    if((H_cycle + L_cycle) != 0){
    Freq = 1000000 / (H_cycle + L_cycle);   // covert H + L cycles in Micro seconds to Frequency
  }

    // format output string
    snprintf_P(str_Freq, sizeof(str_Freq), PSTR("Freq: %u Hz"), Freq);

    // output string to serial port
    Serial.println (str_Freq);

    // output string to tft display
    tft.setCursor(0, 0, 4);
    tft.setTextColor(TFT_GREEN,TFT_BLACK);
    tft.println("IR Meter");
  tft.println("");
    tft.println(str_Freq);
  //delay(3000);
}