Example Code for Arduino UNO - Read Air Quality Data via Software Serial

Hardware Preparation

• Arduino UNO x 1
• Air Quality Monitor x 1
• M-M/F-M/F-F Jumper wires

Software Preparation

• Arduino IDE Click to Download Arduino IDE from Arduino®

Wiring Diagram

Other Preparation Work

Software serial port is used here to communicate with the sensor because Arduino UNO has only one serial port and it's connected to USB.

Sample Code

/*!
 * @file  SEN0233.ino
 * @brief Air Quality Monitor (PM 2.5, HCHO, Temperature & Humidity)
 * @n Get the module here: https://www.dfrobot.com/product-1612.html
 * @n This example is to detect formaldehyde, PM2.5, temperature and humidity in the environment.
 * @copyright  Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
 * @license  The MIT License (MIT)
 * @author  [lijun]([email protected])
 * @version  V1.0
 * @date  2017-03-01
 */

#include <SoftwareSerial.h>

char col;
unsigned int PMSa1 = 0, PMSa2_5 = 0, PMSa10 = 0, FMHDSa = 0, TPSa = 0, HDSa = 0, PMSb1 = 0, PMSb2_5 = 0, PMSb10 = 0, FMHDSb = 0, TPSb = 0, HDSb = 0;
unsigned int PMS1 = 0,PMS2_5 = 0,PMS10 = 0, FMHDS = 0, TPS = 0, HDS = 0, CR1 = 0, CR2 = 0;
unsigned char bufferRTT[32] = {}; //serial receive data
char tempStr[15];

SoftwareSerial mySerial(10, 11); // RX, TX

void setup()
{
  Serial.begin(115200);
  mySerial.begin(9600);
}

void loop()
{

  while (!mySerial.available());
  while (mySerial.available() > 0) //Check whether there is any serial data
  {
    for (int i = 0; i < 32; i++)
    {
      col = mySerial.read();
      bufferRTT[i] = (char)col;
      delay(2);
    }

    mySerial.flush();

    CR1 = (bufferRTT[30] << 8) + bufferRTT[31];
    CR2 = 0;
    for (int i = 0; i < 30; i++)
      CR2 += bufferRTT[i];
    if (CR1 == CR2)               //Check
    {
      PMSa1 = bufferRTT[10];      //Read PM1 high 8-bit data
      PMSb1 = bufferRTT[11];      //Read PM1 low 8-bit data
      PMS1 = (PMSa1 << 8) + PMSb1;   //PM1 data

      PMSa2_5 = bufferRTT[12];      //Read PM2.5 high 8-bit data
      PMSb2_5 = bufferRTT[13];      //Read PM2.5 low 8-bit data
      PMS2_5 = (PMSa2_5 << 8) + PMSb2_5;   //PM2.5 data

      PMSa10 = bufferRTT[14];      //Read PM10 high 8-bit data
      PMSb10 = bufferRTT[15];      //Read PM10 low 8-bit data
      PMS10 = (PMSa10 << 8) + PMSb10;   //PM10 data

      TPSa = bufferRTT[24];      //Read temperature high 8-bit data
      TPSb = bufferRTT[25];      //Read temperature low 8-bit data
      TPS = (TPSa << 8) + TPSb;   //Temperature data

      HDSa = bufferRTT[26];      //Read humidity high 8-bit data
      HDSb = bufferRTT[27];      //Read humidity low 8-bit data
      HDS = (HDSa << 8) + HDSb;   //Humidity data
    }
    else
    {
      PMS1 = 0;
      PMS2_5 = 0;
      PMS10 = 0;
      TPS = 0;
      HDS = 0;
    }
  }

  Serial.println("-----------------------uart--------------------------");
  Serial.print("Temp : ");
  sprintf(tempStr, "%d%d.%d", TPS / 100, (TPS / 10) % 10, TPS % 10);
  Serial.print(tempStr);
  Serial.println(" C");              //Display temperature
  Serial.print("RH   : ");
  sprintf(tempStr, "%d%d.%d", HDS / 100, (HDS / 10) % 10, HDS % 10);
  Serial.print(tempStr);            //Display humidity
  Serial.println(" %");               //%
  Serial.print("PM1.0: ");
  Serial.print(PMS1);
  Serial.println(" ug/m3"); //Display PM1.0 unit  ug/m³ 
  Serial.print("PM2.5: ");
  Serial.print(PMS2_5);
  Serial.println(" ug/m3"); //Display PM2.5 unit  ug/m³ 
  Serial.print("PM 10: ");
  Serial.print(PMS10);
  Serial.println(" ug/m3"); //Display PM 10 unit  ug/m³ 
}

Result