基于夏普DN7C3CA002及arduino UNO的PM2.5监测装置 -

#include
#include
#define LCD_led 9
#define clockPin A0
#define dataPin A1
#define DUSTOUTpin A2 //read dust value from this pin
#define DUSTLEDpin A3 //control dust led through this pin
LiquidCrystal lcd(2, 4, 5, 6, 7, 8);
SHT1x sht1x(dataPin, clockPin);
const int delayTime=280;
const int delayTime2=40;
const float offTime=9680;
float temp_c=0.0;
float humidity=0.0;
double dustVal=0.0;
double voteChange = 5000.0 /1024.0; //mV
#define FREEPMVALUE 3
#define FREEPMTEMP 31.0
#define BASERATIO40 6 //mV
#define BASERATIO60 1.5 //mV
#define PMFIX 0 // 25 ug/m3
#define PMRATIO 0.6
#define DOBASEFIX false
#define NSAMPLES 100
uint8_t sampleCount = 0;
int sampleSumPm = 0;
int dustLevel=0;
//moving average filter
#define NULLVALUE -1.0
#define MOVINGAVERAGECOUT 10
double pm2_5[MOVINGAVERAGECOUT];
uint8_t arrNewPoint = 0;
static void initFilterArray()
{
for(int i=0;i<movingaveragecout;i++)
{
pm2_5[i]=NULLVALUE;
}
}
int readPM(){
// ledPower is any digital pin on the arduino connected to Pin 3 on the sensor
digitalWrite(DUSTLEDpin,LOW);// power on the LED
delayMicroseconds(delayTime);
int Val = analogRead(DUSTOUTpin); // read the dust value via pin 5 on the sensor
delayMicroseconds(delayTime2);
digitalWrite(DUSTLEDpin,HIGH); // turn the LED off
delayMicroseconds(offTime);
return Val;
}
void setup() {
pinMode(LCD_led, OUTPUT);
digitalWrite(LCD_led, HIGH);
pinMode(DUSTLEDpin,OUTPUT);
digitalWrite(DUSTLEDpin,HIGH);// turn the LED off
initFilterArray();
lcd.begin(16, 2);
lcd.print("System Warming!");
//Serial.begin(9600);
delay(5000);
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("PM2.5:");
lcd.setCursor(11, 0);
lcd.print("ug/m3");
lcd.setCursor(5, 1);
lcd.print("C");
lcd.setCursor(15, 1);
lcd.print("%");
}
void loop() {
dustLevel =readPM();
sampleCount++;
sampleSumPm = sampleSumPm + dustLevel;
if(sampleCount==NSAMPLES)
{
showTempHumiData();
getPMdata(sampleSumPm / sampleCount);
sampleCount=0;
sampleSumPm=0;
}
}
void getPMdata(int avgPm) {
double dustVolt = avgPm * voteChange; //mV
if(DOBASEFIX)
{
double baseVot = FREEPMVALUE * voteChange; //mV
double baseChg = 0.0;
if(temp_c <= 40.0 && temp_c>= -10.0)
{
baseChg=BASERATIO40;
}
else if(temp_c > 40.0 && temp_c <= 60.0)
{
baseChg=BASERATIO60;
}
baseVot=baseVot + baseChg*(temp_c - FREEPMTEMP);
dustVolt=dustVolt-baseVot;
if(dustVolt<0)
{
dustVolt=0;
}
}
dustVal = dustVolt * PMRATIO;
dustVal = dustVal + PMFIX;
// moving average
getMovingAverage(pm2_5,&dustVal);
lcd.setCursor(6, 0);
lcd.print(" ");
lcd.setCursor(6, 0);
lcd.print(dustVal,0);
}
void showTempHumiData() {
temp_c = sht1x.readTemperatureC();
humidity = sht1x.readHumidity();
lcd.setCursor(0, 1);
lcd.print(" ");
lcd.setCursor(0, 1);
lcd.print(temp_c,1);
lcd.setCursor(12, 1);
lcd.print(" ");
lcd.setCursor(12, 1);
lcd.print(humidity,0);
}
static float getAverage(double vals[])
{
double sum=0.0;
uint8_t cout=0;
for(int i=0;i<movingaveragecout;i++)
{
if(vals[i] != NULLVALUE)
{
sum=sum+vals[i];
cout++;
}
}
if(cout>0)
{
return sum/cout;
}
else
{
return 0.0;
}
}
static void getMovingAverage(double pms[],double* pm)
{
pms[arrNewPoint] = *pm;
arrNewPoint++;
if(arrNewPoint>=MOVINGAVERAGECOUT)
{
arrNewPoint=0;
}
*pm=getAverage(pms);
}

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