// Sietse Jonker 
// 09/02/2024

#include <Wire.h>         // Only needed for Arduino 1.6.5 and earlier
#include "SSD1306Wire.h"  // legacy: #include "SSD1306.h"
#include "Adafruit_SGP30.h"
#include "images.h"
#include "DHT.h"

#define DHTPIN 7

#define DHTTYPE DHT11

SSD1306Wire display(0x3c, SDA, SCL);  // ADDRESS, SDA, SCL  -  SDA and SCL usually populate automatically based on your board's pins_arduino.h e.g. https://github.com/esp8266/Arduino/blob/master/variants/nodemcu/pins_arduino.h
DHT dht(DHTPIN, DHTTYPE);
Adafruit_SGP30 sgp;

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;
}

void setup() {
  Serial.begin(115200);

  // Initialising the UI will init the display too.
  display.init();
  dht.begin();

  display.flipScreenVertically();

  Serial.println("SGP30 test");

  if (!sgp.begin()) {
    Serial.println("Sensor not found :(");
    while (1)
      ;
  }
  Serial.print("Found SGP30 serial #");
  Serial.print(sgp.serialnumber[0], HEX);
  Serial.print(sgp.serialnumber[1], HEX);
  Serial.println(sgp.serialnumber[2], HEX);
}

void loop() {
  display.clear();

  display.setFont(ArialMT_Plain_24);
  display.setTextAlignment(TEXT_ALIGN_LEFT);
  display.drawString(0, 0, String(sgp.eCO2) + "ppm");
  display.drawString(0, 32, String(dht.readTemperature()));

  display.display();

  if (!sgp.IAQmeasure()) {
    Serial.println("Measurement failed");
    return;
  }

  uint16_t TVOC_base, eCO2_base;
  if (!sgp.getIAQBaseline(&eCO2_base, &TVOC_base)) {
    Serial.println("Failed to get baseline readings");
    return;
  }


  Serial.print("eCO2 ");
  Serial.print(sgp.eCO2);
  Serial.println(" ppm");

  delay(1000);
}