SGP30 Sensor

//*******************************************
//*        SGP30 Sensor w/ 2x16 LCD         *
//*                                         *
//*      learnelectronic 26, June, 2020     *
//*                                         *
//*      www.youtube.com/learnelectronics   *
//*                                         *
//*      email: [email protected]       *
//*******************************************

#include "rgb_lcd.h"                            //I2C Library for LCD
#include <Wire.h>                               //I2C Library
#include "Adafruit_SGP30.h"                     //SGP30 Sensor Library


rgb_lcd lcd;                                    //assign name lcd to rgb_lcd
Adafruit_SGP30 sgp;                             //assign name sgp to sensor


// Function to read from sensor
     uint32_t getAbsoluteHumidity(float temperature, float humidity) {
// approximation formula from Sensirion SGP30 Driver Integration chapter 3.15
    const float absoluteHumidity = 216.7f * ((humidity / 100.0f) * 6.112f * exp((17.62f * temperature) / (243.12f + temperature)) / (273.15f + temperature)); // [g/m^3]
    const uint32_t absoluteHumidityScaled = static_cast<uint32_t>(1000.0f * absoluteHumidity); // [mg/m^3]
    return absoluteHumidityScaled;
}

int counter = 0;                                //setup a counter variable(global)


void setup() {
    Serial.begin(9600);                         //start serial comms for debug

    lcd.begin(16, 2);                           // set up the LCD's number of columns and rows


 if (! sgp.begin()){
    Serial.println("Sensor not found :(");      //check for sensor on I2c bus
    while (1);
  }
  Serial.print("Found SGP30 serial #");         //return serial number of sensor
  Serial.print(sgp.serialnumber[0], HEX);
  Serial.print(sgp.serialnumber[1], HEX);
  Serial.println(sgp.serialnumber[2], HEX);

}

void loop()
{

    lcd.setCursor(0, 0);                        // set the cursor to column 0, line 1
                                                // (note: line 1 is the second row, since counting begins with 0):

     if (! sgp.IAQmeasure()) {
    Serial.println("Measurement failed");       //Get reading from sensor
    return;
  }

  if (! sgp.IAQmeasureRaw()) {
    Serial.println("Raw Measurement failed");   //Get reading from sensor
    return;
  }

lcd.print("TVOC ");
lcd.print(sgp.TVOC);                            //print total voc's on line 0
lcd.print(" ppb");


   lcd.setCursor(0, 1);
   lcd.print("eCO2 ");
   lcd.print(sgp.eCO2);                         //print total eCo2 on line 1
   lcd.print(" ppm");

  delay(1000);                                  //wait one second

  counter++;                                    //increment counrt up to 30, at 30 reset
  if (counter == 30) {
    counter = 0;


                                                //create variables for sensor readings
    uint16_t TVOC_base, eCO2_base;
    if (! sgp.getIAQBaseline(&eCO2_base, &TVOC_base)) {
      Serial.println("Failed to get baseline readings");
      return;
    }
    Serial.print("****Baseline values: eCO2: 0x"); Serial.print(eCO2_base, HEX);
    Serial.print(" & TVOC: 0x"); Serial.println(TVOC_base, HEX);
  }

lcd.setCursor(0, 0);                            //clear the screen
lcd.print("                ");
lcd.setCursor(0, 01);
lcd.print("                ");
}