M5StickCで　温度と湿度と二酸化炭素とVOCの測定してみた

前回投稿したお礼　いただいたM5StickCを使って二酸化炭素濃度測定　にDHT11をつけてSGP30の温度湿度補正と温度湿度表示も加えてみました。

M5StickC
　SGP30
　DHT11はデータとVCCの間に10kΩのプルアップ抵抗を入れています。
　接続はVCC3.3V データはG26 GNDの３本です。

#include <Wire.h>
#include "Adafruit_SGP30.h"
#include <DHT.h>
#define DHTPIN 26
#define DHTTYPE DHT11
DHT dht(DHTPIN, DHTTYPE);

#define DISP_BRIGHTNESS_MIN  9
uint8_t disp_brightness = DISP_BRIGHTNESS_MIN;
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() {
  M5.Axp.ScreenBreath(disp_brightness);
  M5.begin();
  M5.Lcd.setRotation(1);
  M5.Lcd.setTextFont(2);
  M5.Lcd.setTextColor(TFT_WHITE,TFT_BLACK);  
  M5.Lcd.fillScreen(BLACK);
  
  Serial.begin(115200);
  
  while (!Serial) { delay(10); } // Wait for serial console to open!
  Serial.println("SGP30 test");


  Wire.begin(32, 33);//I2C
  dht.begin();
  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);

  // If you have a baseline measurement from before you can assign it to start, to 'self-calibrate'
  //sgp.setIAQBaseline(0x8E68, 0x8F41);  // Will vary for each sensor!
  M5.Lcd.fillScreen(WHITE);
  delay(500);
  M5.Lcd.fillScreen(BLACK);
  delay(500);
  
  // text print
  M5.Axp.ScreenBreath(disp_brightness);
  M5.Lcd.fillScreen(BLACK);
  M5.Lcd.setCursor(0, 10);
  M5.Lcd.setTextColor(WHITE);
  M5.Lcd.setTextSize(1);
  M5.Lcd.printf("Display Test!");
   delay(1000); 
}

int counter = 0;
void loop() {
  
float DHThumidity = dht.readHumidity();
float DHTtemperature = dht.readTemperature();
    String datath = ""+String(DHTtemperature)+" "+String(DHThumidity);
    
  // If you have a temperature / humidity sensor, you can set the absolute humidity to enable the humditiy compensation for the air quality signals
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();
  sgp.setHumidity(getAbsoluteHumidity(temperature, humidity));

  if (! sgp.IAQmeasure()) {
    Serial.println("Measurement failed");
    return;
  }
Serial.print(datath);
Serial.print(" ");Serial.print(sgp.TVOC);
Serial.print(" "); Serial.println(sgp.eCO2);

  if (! sgp.IAQmeasureRaw()) {
    Serial.println("Raw Measurement failed");
    return;
  }
 
  delay(1000);

  counter++;
  if (counter == 30) {
    counter = 0;

    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);
  }


  //Add M5stick OLED 
  M5.Lcd.fillScreen(BLACK); 
    String str = "      " + (String)sgp.TVOC + "[ppb] ";
  M5.Lcd.drawRightString(str,250,0,2);
   M5.Lcd.setCursor(0, 0, 2);
  M5.Lcd.println(" TVOC");
 str = "      " + (String)sgp.eCO2 + "[ppm] ";
  M5.Lcd.drawRightString(str,250,16,2);
  M5.Lcd.setCursor(0, 16, 2);
  M5.Lcd.println(" eCO2");
    M5.Lcd.setCursor(0, 32, 2);
  M5.Lcd.println(" Temp");
   str = "      " + (String)DHTtemperature + "[C] ";
  M5.Lcd.drawRightString(str,250,32,2);
     M5.Lcd.setCursor(0, 32+16, 2);
  M5.Lcd.println(" Humi");
   str = "      " + (String)DHThumidity + "[%] ";
  M5.Lcd.drawRightString(str,250,32+16,2);
  delay(3000);
}

プログラム作成にはArduinoIDE使っています。
ボードマネージャーで　M5Stick-Cを設定
センサーはライブラリマネージャでAdafruitの"SGP30"とAdafruitの"DHT sensor library"を
それぞれインストールしています。