Waveshare-Dust-Sensor-code.ino

// This example allow send data using UDP protocol

#include "Ubidots/Ubidots.h"
#define TOKEN "CCN8FrVulRYGulPTkbxxxxxxxxxxxxx"  // Put here your Ubidots TOKEN
#define LED D0
#define VARIABLE_NAME "DUST"
#define DATA_SOURCE_LABEL "waveshare-dust-sensor"
#define DATA_SOURCE_NAME "Waveshare Dust Sensor"


#define        COV_RATIO                       0.2            //ug/mmm / mv
#define        NO_DUST_VOLTAGE                 400            //mv
#define        SYS_VOLTAGE                     3300      

Ubidots ubidots(TOKEN);

float density, voltage;
int   adcvalue;

void setup() {  
    Serial.begin(115200);
    pinMode(LED, OUTPUT);
    digitalWrite(LED, LOW);
    ubidots.setDatasourceName(DATA_SOURCE_NAME);
    ubidots.setDatasourceTag(DATA_SOURCE_LABEL);
}
void loop() {
    digitalWrite(LED, HIGH);
    delayMicroseconds(280);
    int dust = analogRead(A0);
    digitalWrite(LED, LOW);
    adcvalue = Filter(dust);
    /*
    covert voltage (mv)
    */
    voltage = (0.8 * adcvalue * 11);
    /*
    voltage to density
    */
    if (voltage >= NO_DUST_VOLTAGE) {
        voltage -= NO_DUST_VOLTAGE;
        density = voltage * COV_RATIO;
    }
    else
    density = 0;
    
    ubidots.add(VARIABLE_NAME, density);
    ubidots.sendAll();
    delay(5000);
}
int Filter(int m)
{
  static int flag_first = 0, _buff[10], sum;
  const int _buff_max = 10;
  int i;
  
  if(flag_first == 0)
  {
    flag_first = 1;

    for(i = 0, sum = 0; i < _buff_max; i++)
    {
      _buff[i] = m;
      sum += _buff[i];
    }
    return m;
  }
  else
  {
    sum -= _buff[0];
    for(i = 0; i < (_buff_max - 1); i++)
    {
      _buff[i] = _buff[i + 1];
    }
    _buff[9] = m;
    sum += _buff[9];
    
    i = sum / 10.0;
    return i;
  }
}