Датчик пыли SDS011. Ставим три разных датчика в одно устройство.

Программисту на заметку:

В демонстрационных программах, которые можно найти на гитхабе, со временем промашка. Чтобы успеть все правильно измерить, нужно приступать уже через 200 мкс после включения диода, а не чрез 280, как там пишут.

delayMicroseconds(200); // was 280, but real 320mks at 200 setting

Программисту на заметку:

Вот моя формула:

y = -0.088496207228664*x^4 — 2.5505502324503*x^3 — 21.92053783603786*x^2 + 172.17128476610927*x — 90.1119605706346

Где

х — процент времени, когда присутствует сигнал от датчика, 0-100%

y — концентрация пыли, мкг/м3

Формула очень хорошо коррелирует с графиком из датшита, но совсем не коррелирует с действительностью, увы.

Код скрипта

/////////////////// © Tykhon, 2019 ////////////////////////////////////

#include "Wire.h"

#include <SoftwareSerial.h>

#include <TFT.h> 

/////////////////// for DSM501 sensor ////////////////////////////////////

int pinV2 = 6;

int pinV1 = 5;

unsigned long durationV1;

unsigned long durationV2;

unsigned long starttimeV1;

unsigned long starttimeV2;

unsigned long lowpulseoccupancyV1 = 0;

unsigned long lowpulseoccupancyV2 = 0;

float one_to_two_point_five;

float ratioV1 = 0;

float ratioV2 = 0;

boolean flagV1 = true;

boolean flagV2 = true;

boolean V1 = false;

boolean V2 = false;

float concentrationV1 = 0;

float concentrationV2 = 0;

int allV1, allV2, goodV1, goodV2;



/////////////////// for Sharp sensor ////////////////////////////////////

unsigned long LastCheckSharp;

const int sharpLEDPin = 4;   // Arduino digital pin 2 connect to sensor LED.

const int sharpVoPin = A6;   // Arduino analog pin A6 connect to sensor Vo.

static unsigned long VoRawTotal = 0;

int VoRawCount = 0;

static float Voc = 0.45;

float dustDensity = 0.0;

float Vo = 0.0;

float Dust = 0.0;



/////////////////// for general purposes ////////////////////////////////

unsigned long starttime;

unsigned long endtime;

unsigned long sampletime_ms = 30000;

unsigned long now;

unsigned long loops;

#define DS1307_ADDR 0x68                     // RTC address



/////////////////// for LCD ////////////////////////////////////////////



#define TFT_CS     10

#define TFT_RST    9  

#define TFT_DC     8

int line_25[85] = {};  

int line_10[85] = {};  

byte lineIndex;

TFT TFTscreen = TFT(TFT_CS, TFT_DC, TFT_RST);

char one_to_two_point_fivec[5], Dustc[5], Pm25fc[5], Pm10fc[5];



////////////////// for SDS 011 sensor //////////////////////////////////

int rxPin = 3;

int txPin = 2;

SoftwareSerial mySerial(3, 2); //RX, TX

unsigned int Pm25 = 0;

unsigned int Pm10 = 0;

float Pm25f = 0.0;

float Pm10f = 0.0;

int sdspoll = 0;

unsigned int Pm25sum = 0;

unsigned int Pm10sum = 0;

unsigned long lastsds;

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

void setup()

{

  Serial.begin(9600);

  mySerial.begin(9600);

  pinMode(pinV1,INPUT);

  pinMode(pinV2,INPUT);

  pinMode(sharpLEDPin, OUTPUT);

  starttime = millis(); 

  Wire.begin();

  TFTscreen.begin(); 

  TFTscreen.setRotation(2); 

  TFTscreen.background(20,0,0); 

  TFTscreen.stroke(200,200,200);

  TFTscreen.setTextSize(2);

  TFTscreen.text("DSM", 2, 5);  

  TFTscreen.text("Sharp", 2, 35);  

  TFTscreen.stroke(0,250,250);

  TFTscreen.text("Pm10", 2, 65); 

  TFTscreen.stroke(180,10,250);

  TFTscreen.text("Pm2.5", 2, 95);  

}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////



/////////////////// for date and time //////////////////////////////////

byte bcdToDec(byte val)  {

  return ( (val/16*10) + (val%16) );

}

/////////////////// returns date and time //////////////////////////////////

String getdate(){

  Wire.beginTransmission(DS1307_ADDR);

  byte zero = 0x00;

  Wire.write(zero);

  Wire.endTransmission();

  Wire.requestFrom(DS1307_ADDR, 7);

  int secondint = bcdToDec(Wire.read());

  int minuteint = bcdToDec(Wire.read());

  int hour = bcdToDec(Wire.read() & 0b111111); //24 hour time

  int weekDay = bcdToDec(Wire.read()); //0-6 -> sunday - Saturday

  int monthDay = bcdToDec(Wire.read());

  int month = bcdToDec(Wire.read());

  int year = bcdToDec(Wire.read());

  String second = String(secondint); if (secondint < 10) {second ="0"+second;};

  String minute = String(minuteint); if (minuteint < 10) {minute ="0"+minute;};

  return String(hour)+":"+minute+":"+second+"  "+String(monthDay)+"/"+String(month)+"/"+String(year);  /// 

}

//////////////////// draws graph  ////////////////////////////////////////

void tft_graph(){

  byte k = 30;

  TFTscreen.stroke(20,0,0);

  TFTscreen.fill(20,0,0);

  TFTscreen.rect(0, TFTscreen.height()-45, TFTscreen.width(), 45);

  TFTscreen.stroke(250,180,10);

  

  TFTscreen.line(5, 90+k, 5, 121+k);

  TFTscreen.line(5, 121+k, 90, 121+k);

  int maxvalue = 0;

  for (int i = 0; i < (sizeof(line_10)/sizeof(int)); i++){

    maxvalue = max(maxvalue, line_10[i]);

    maxvalue = max(maxvalue, line_25[i]);

  };

  int g = 5+(sizeof(line_10)/sizeof(int));

  for (int i = lineIndex-1; i >= 0; i--){ 

    int x1 = g;

    g--;

    int y1 = map(line_10[i],maxvalue,0,90+k,120+k);

    int y2 = map(line_25[i],maxvalue,0,90+k,120+k);

        

    TFTscreen.stroke(10,180,250);

    TFTscreen.point(x1, y1); 

    TFTscreen.stroke(180,10,250);

    TFTscreen.point(x1, y2); 

  };

  for (int i = (sizeof(line_10)/sizeof(int))-1; i >= lineIndex; i--){ 

    int x1 = g;

    g--;

    int y1 = map(line_10[i],maxvalue,0,90+k,120+k);

    int y2 = map(line_25[i],maxvalue,0,90+k,120+k);

    TFTscreen.stroke(10,180,250);

    TFTscreen.point(x1, y1); 

    TFTscreen.stroke(180,10,250);

    TFTscreen.point(x1, y2); 

  };  

}

///////////////////// prints data on screen ///////////////////////////

void tft_output(){

  TFTscreen.stroke(20,0,0);

  TFTscreen.text(one_to_two_point_fivec, 70, 5);  

  TFTscreen.text(Dustc, 70, 35);  

  TFTscreen.text(Pm10fc, 70, 65);  

  TFTscreen.text(Pm25fc, 70, 95);  

  String one_to_two_point_fives = String(one_to_two_point_five);

  String Dusts = String(Dust);

  String Pm10fs = String(Pm10f);

  String Pm25fs = String(Pm25f);

  one_to_two_point_fives.toCharArray(one_to_two_point_fivec,5);

  Dusts.toCharArray(Dustc,5);

  Pm10fs.toCharArray(Pm10fc,5);

  Pm25fs.toCharArray(Pm25fc,5);

  TFTscreen.stroke(255,255,255);

  TFTscreen.text(one_to_two_point_fivec, 70, 5);  

  TFTscreen.text(Dustc, 70, 35);  

  TFTscreen.text(Pm10fc, 70, 65);  

  TFTscreen.text(Pm25fc, 70, 95);  

}



//////////////////  reads serial port and decodes data //////////////////////



void ProcessSerialData()

{

  uint8_t mData = 0;

  uint8_t i = 0;

  uint8_t mPkt[10] = {0};

  uint8_t mCheck = 0;

  while (mySerial.available() > 0)

  {

    // from www.inovafitness.com

    // packet format: AA C0 PM25_Low PM25_High PM10_Low PM10_High 0 0 CRC AB

    mData = mySerial.read();     delay(2);//wait until packet is received

    if (mData == 0xAA) //head1 ok

    {

      mPkt[0] =  mData;

      mData = mySerial.read();

      if (mData == 0xc0) //head2 ok

      {

        mPkt[1] =  mData;

        mCheck = 0;

        for (i = 0; i < 6; i++) //data recv and crc calc

        {

          mPkt[i + 2] = mySerial.read();

          delay(2);

          mCheck += mPkt[i + 2];

        }

        mPkt[8] = mySerial.read();

        delay(1);

        mPkt[9] = mySerial.read();

        if (mCheck == mPkt[8]) //crc ok

        {

          mySerial.flush();

          Pm25 = (uint16_t)mPkt[2] | (uint16_t)(mPkt[3] << 8);

          Pm10 = (uint16_t)mPkt[4] | (uint16_t)(mPkt[5] << 8);

          if (Pm25 > 9999)

            Pm25 = 9999;

          if (Pm10 > 9999)

            Pm10 = 9999;

          return;

        }

      }

    }

  }

}



//////////////////  sends SLEEP command to SDS011  //////////////////////

void SDS011sleep()

{

  while (mySerial.available() > 0)

  {

    uint8_t sleep_command[] = {0xAA, 0xB4, 0x06, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0x05, 0xAB};

    for (uint8_t i = 0; i < 19; i++) {

      mySerial.write(sleep_command[i]);

    }

    mySerial.flush();

  }

}

//////////////////  sends WAKEUP command to SDS011  //////////////////////

void SDS011wakeup()

{

  while (mySerial.available() > 0)

  {

    uint8_t wakeup_command[] = {0xAA, 0xB4, 0x06, 0x01, 0x01, 0xC5};

    for (uint8_t i = 0; i < 6; i++) {

        mySerial.write(wakeup_command[i]);

    }

  }

}  

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

void loop()

{

  loops +=1;

  now = millis();

//////////////  Sharp  ////////////////////////

  

  if ((now - LastCheckSharp) >= 10) {

    LastCheckSharp = now;

    digitalWrite(sharpLEDPin, LOW);

    delayMicroseconds(200);  // was 280, but real 320mks at 200 setting

    int VoRaw = analogRead(sharpVoPin);

    digitalWrite(sharpLEDPin, HIGH);

    VoRawTotal += VoRaw;

    VoRawCount++;

  };

////////////  DSM 501 ////////////////////////

  V1 = digitalRead(pinV1);

  if ((flagV1)&&!(V1)) {         // start period of low V1

      starttimeV1 = millis();

      flagV1 = false;

  };

  if (!(flagV1)&&(V1)) {         // stop period of low V1

      durationV1 = millis() - starttimeV1;

      flagV1 = true;

      allV1+=1;

 

    if ((durationV1 <= 90)&&(durationV1 >= 10)) {

      lowpulseoccupancyV1 += durationV1;

      goodV1+=1;

    };

  };

  V2 = digitalRead(pinV2);

  if ((flagV2)&&!(V2)) {         // start period of low V2

      starttimeV2 = millis();

      flagV2 = false;

  };

  if (!(flagV2)&&(V2)) {         // stop period of low V2

      durationV2 = millis() - starttimeV2;

      flagV2 = true;

      allV2+=1;

 

  if ((durationV2 <= 90)&&(durationV2 >= 10)) {

    lowpulseoccupancyV2 += durationV2;

    goodV2+=1;

  };

 };

//////////// SDS 011  ////////////////////////

    if ((now - lastsds)> 1000) {

      lastsds = now;

      sdspoll ++;

      ProcessSerialData();

      Pm25sum +=  Pm25;

      Pm10sum += Pm10;

    };

////////////  output ///////////////////////////////

 

  endtime = millis();

  if ((endtime-starttime) > sampletime_ms)

  {

    Serial.print(getdate());

//////////////////////////

    Vo = 1.0 * VoRawTotal / VoRawCount;

    Vo = Vo / 1024.0 * 5.0;

    float dV = Vo - Voc;

    if (dV < 0 ) {dV = 0; Voc = Vo;};

    Dust = 172.0*dV;

    Serial.print("  Sharp: ");

    Serial.print(Dust);

    VoRawCount = 0;

    VoRawTotal = 0;

//////////////////////////

    

  ratioV1 = (lowpulseoccupancyV1*100.0)/(endtime-starttime);  // Integer percentage 0=>100

  ratioV2 = (lowpulseoccupancyV2*100.0)/(endtime-starttime);  // Integer percentage 0=>100

//    concentrationV1 = 1.1*pow(ratioV1,3)-3.8*pow(ratioV1,2)+520*ratioV1+0.62; // using spec sheet curve in pcs in 1/100 ft3

//    concentrationV2 = 1.1*pow(ratioV2,3)-3.8*pow(ratioV2,2)+520*ratioV2+0.62; // using spec sheet curve in pcs in 1/100 ft3

  concentrationV1 = -0.0885*pow(ratioV1,4) - 2.55055*pow(ratioV1,3)- 21.920538*pow(ratioV1,2) + 172.171285*ratioV1 - 90.112;

  concentrationV2 = -0.0885*pow(ratioV2,4) - 2.55055*pow(ratioV2,3)- 21.920538*pow(ratioV2,2) + 172.171285*ratioV2 - 90.112;

  if (concentrationV1 < 0) {concentrationV1 = 0.0;};

  if (concentrationV2 < 0) {concentrationV2 = 0.0;};

  one_to_two_point_five = concentrationV2 - concentrationV1;

  if (one_to_two_point_five < 0) {one_to_two_point_five = 0;};

  Serial.print("  DSM501_>2.5: ");

  Serial.print(concentrationV1);

  Serial.print("  DSM501_>1.0: ");

  Serial.print(concentrationV2);

    

  Serial.print("  DSM501_1-2.5: ");

  Serial.print(one_to_two_point_five);

 

  lowpulseoccupancyV1 = 0;

  lowpulseoccupancyV2 = 0;

  loops = 0;

  allV1 = 0;

  goodV1 = 0;

  allV2 = 0;

  goodV2 = 0;



///////////// SDS011 /////////////////

  Pm25f = Pm25sum/(sdspoll*10.0);

  Pm10f = Pm10sum/(sdspoll*10.0);

  Serial.print("  Pm2.5 ");

  Serial.print(Pm25f,2);

  Serial.print("  Pm10 ");

  Serial.print(Pm10f,2);

  sdspoll = 0;

  Pm25sum = 0;

  Pm10sum = 0;

  line_25[lineIndex] = int(Pm25f*100.0);

  line_10[lineIndex] = int(Pm10f*100.0);

  lineIndex++;

  if (lineIndex >= 85) {lineIndex = 0;};



//////////// finish ///////////////

  

  tft_output();

  Serial.println();

  tft_graph();

  starttime = millis();

  }             // if 30 sec passed

 

}   // loop