IPSIA “R. FRAU”

A.S. 2019/2020

LABORATORIO DI FISICA CON ARDUINO Prof. Lorenzo Morresi

Classe 3EMT-MAT San Ginesio

Titolo progetto

Tester per la qualità dell’aria – PM10 e PM2.5 –

Scheda progetto n_21

Descrizione

Realizziamo un tester per la misura della qualità dell’aria (Air Test Quality) in grado di rilevare la materia particolata (Particulate Matter – PM) di diametro fino a 10 µm (PM10) e fino a 2.5 µm (PM2.5). Il sensore utilizzato è un PPD42ns della Shinyei che con le sue due uscite P1 e P2 permette di riconoscere e quantificare le due quantità di particelle presenti nell’aria. I valori ottenuti vengono mostrati sia sul monitor seriale che sul display lcd collegato alla base shield di Arduino mediante la porta I2C.

Materiale necessario

1 ARDUINO UNO board 1 Sensore PPD42ns - Shinyei 1 Display LCD – I2C 1 Grove Starter Kit per Arduino 1 Grove Base Shield

qui trovi i link

Sketch

#include <Wire.h> #include <rgb_lcd.h> rgb_lcd lcd; byte micr[8] = {B00000,B00000,B00000,B10010,B10010,B10010,B11110,B10000}; byte cubo[8] = {B11000,B00100,B11000,B00100,B11000,B00000,B00000,B00000}; unsigned long starttime; unsigned long triggerOnP1; unsigned long triggerOffP1; unsigned long pulseLengthP1; unsigned long durationP1; boolean valP1 = HIGH; boolean triggerP1 = false; unsigned long triggerOnP2; unsigned long triggerOffP2; unsigned long pulseLengthP2; unsigned long durationP2; boolean valP2 = HIGH; boolean triggerP2 = false; float ratioP1 = 0; float ratioP2 = 0; unsigned long sampletime_ms = 3000; float countP1; float countP2; void setup(){

lcd.begin(16,2); lcd.createChar(0,micr); lcd.createChar(1,cubo); lcd.clear(); lcd.setCursor(0, 0); lcd.print("LORENZO MORRESI"); lcd.setCursor(0, 1); lcd.print("Air Quality Test"); delay (6000); pinMode(8, INPUT); pinMode(9, INPUT); Serial.begin(9600); } void loop(){ valP1 = digitalRead(8); valP2 = digitalRead(9); if(valP1 == LOW && triggerP1 == false){ triggerP1 = true; triggerOnP1 = micros(); } if (valP1 == HIGH && triggerP1 == true){ triggerOffP1 = micros(); pulseLengthP1 = triggerOffP1 - triggerOnP1; durationP1 = durationP1 + pulseLengthP1; triggerP1 = false; } if(valP2 == LOW && triggerP2 == false){ triggerP2 = true; triggerOnP2 = micros(); } if (valP2 == HIGH && triggerP2 == true){ triggerOffP2 = micros(); pulseLengthP2 = triggerOffP2 - triggerOnP2; durationP2 = durationP2 + pulseLengthP2; triggerP2 = false; } if ((millis() - starttime) > sampletime_ms) { ratioP1 = durationP1/(sampletime_ms*10.0); // Integer percentage 0=>100 ratioP2 = durationP2/(sampletime_ms*10.0); countP1 = 1.1*pow(ratioP1,3)-3.8*pow(ratioP1,2)+520*ratioP1+0.62; countP2 = 1.1*pow(ratioP2,3)-3.8*pow(ratioP2,2)+520*ratioP2+0.62; float PM10count = countP2; float PM25count = countP1 - countP2; // first, PM10 count to mass concentration conversion double r10 = 2.6*pow(10,-6); double pi = 3.14159; double vol10 = (4/3)*pi*pow(r10,3); double density = 1.65*pow(10,12);

double mass10 = density*vol10; double K = 3531.5; float concLarge = (PM10count)*K*mass10; // next, PM2.5 count to mass concentration conversion double r25 = 0.44*pow(10,-6); double vol25 = (4/3)*pi*pow(r25,3); double mass25 = density*vol25; float concSmall = (PM25count)*K*mass25; //scrittura sul monitor seriale Serial.print("PM10 count ="); Serial.print(PM10count); Serial.println(" pt/cf"); Serial.print("PM2.5 count ="); Serial.print(PM25count); Serial.println(" pt/cf"); Serial.print("PM10 conc ="); Serial.print(concLarge); Serial.println(" ug/m3"); Serial.print("PM2.5 conc ="); Serial.print(concSmall); Serial.println(" ug/m3"); //scrittura su display lcd lcd.clear(); lcd.print("PM10 : "); lcd.print(concLarge); lcd.setCursor(11,0); lcd.write(byte(0)); lcd.print("g/m"); lcd.write(byte(1)); lcd.setCursor(0,1); lcd.print("PM2.5: "); lcd.print(concSmall); lcd.setCursor(11,1); lcd.write(byte(0)); lcd.print("g/m"); lcd.write(byte(1)); durationP1 = 0; durationP2 = 0; starttime = millis(); } }

Schema dei collegamenti

Dettaglio connessioni

sensore ppd42ns

P1 collegato a D8 di ARDUINO P2 collegato a D9 di ARDUINO

ARDUINO Board

GROVE Base Shield

Sensore PPD42ns

Porta D8

Porta I2C

LCD I2C

1 2 3 4 5

GND

P2 +5V P1

Se si usa la Grove Base Shield il connettore proveniente dal PPD42ns deve essere collegato alla sua porta D8.

Dettaglio connessioni display LCD

I2C

Dust sensor - PPN42ns

Vcc collegato a +5V di ARDUINO SDA collegato a A4 di ARDUINO SCL collegato a A5 di ARDUINO

Se si usa la Grove Base Shield il connettore proveniente dal display LCD deve essere collegato ad una delle sue porte I2C.

Risultato atteso

(esempio)

Prova a Inserire un allarme che si attivi quanto il PM10 e/o il PM2.5 supera un certo livello di soglia.

Nome e Cognome

VOTO:

This sensor is to create Digital (Lo Pulse) output to Particulate Matters(PM). Lo Pulse Occupancy time (LPO

time) is in proportion to PM concentration. The output from “P1” is for PM whose size is around 1 micro meter

or larger. “P1” Output characteristics is shown in the attached drawing Fig2.,when tested in standard

condition stipulated below.

Model PPD42NS

Detectable particle size approx. 1μm (minimum.)

Detectable range of concentration 0~28,000 pcs/liter (0~8,000pcs/0.01 CF=283ml)

Supply Voltage DC5V +/- 10% (CN1:Pin1=GND, Pin3=+5V)

Ripple Voltage within 30mV

Operating Temperature Range 0~45°C

Operating Humidity Range 95%rh or less (without dew condensation)

Power consumption 90mA

Storage temperature -30~60°C

Time for stabilization 1 minute after power turned on

Dimensions 59(W) × 45(H) × 22(D) [mm]

Weight 24g(approx.)

Output Method Negative Logic, Digital output,

Hi : over 4.0V(Rev.2) Lo : under 0.7V

(As Input impedance : 200kΩ) OP-Amp output, Pull-up resistor : 10kΩ

The configuration and connector pin allocation are shown in the attached drawing Fig1.

Specification sheet of PPD42NS

03-2010 (Page 1 of 3)

PPaarrttiiccllee SSeennssoorr

Model PPD42NS

Specification

Configuration and connector pin assignment

Rib (inside of housing)

An additional rib structured to inside of housing to hide RH1 lead wire from view. Following components replaced with

equivalent ones; OP-Amp,Volume and Al Electrolytic Cap.

CN : S5B-EH(JST)

1 : COMMON(GND)

2 : OUTPUT(P2)

3 : INPUT(5VDC 90mA)

4 : OUTPUT(P1)

5 : INPUT(T1)･･･FOR THRESHOLD FOR [P2]

Specification sheet of PPD42NS

03-2010 (Page 2 of 3)

Fig. 1

Connector

Hi : 4.0V

LO: 0.7V

PULSE WIDTH = 10ms~90ms

Lo Pulse Occupancy time / unit time (30sec) (%)

Shinyei Corporation of America

24 W 40th street, 4th floor

New York, NY 10018

TEL: 917-484-7884

FAX: 212-704-4206

E-mail : tony.tokuya@sca-shinyei.com

Specification sheet of PPD42NS

03-2010 (Page 3 of 3)

Fig. 2

0%

2%

4%

6%

8%

10%

12%

14%

16%

0 1000 2000 3000 4000 5000 6000 7000 8000

Lo P

uls

e O

ccu

pa

ncy

T

ime

Concentration (pcs/283ml=0.01cf) Particle Size :over 1µm

Smoke(Cigarette)-Output P1 Characteristics

Upper,Lower