3ZWXXnXu

1#include <Adafruit_Sensor.h>
2#include <DHT.h>
3#include <DHT_U.h>
4#include <ESP8266WiFi.h>
5#include <ESP8266WebServer.h>
6#include <SDS011.h>
7#include <SoftwareSerial.h>
8
9
10
11#define SDS_RX D1
12#define SDS_TX D2
13
14#define DHTPIN D4 
15#define DHTTYPE DHT22   
16
17const char* ssid     = "wifi-ssid";
18const char* password = "password";
19const char* host = "api.thingspeak.com";
20String apiKey = ""; // thingspeak.com api key goes here
21
22float p10,p25;
23int error;
24
25struct Air {
26  float pm25;
27  float pm10;
28  float humidity;
29  float temperature;
30};
31
32
33DHT_Unified dht(DHTPIN, DHTTYPE);
34ESP8266WebServer server(80);
35WiFiClient client;
36SDS011 sds;
37
38void setup() {
39  Serial.begin(9600);
40  sds.begin(SDS_RX,SDS_TX);
41  dht.begin();
42  connectToWiFi();
43}
44
45void loop() {
46  Air airData = readPolution();
47  if (client.connect(host,80) & airData.pm25 > 0.0) {
48    String postStr = apiKey;
49    postStr +="&field1=";
50    postStr += String(airData.pm25);
51    postStr +="&field2=";
52    postStr += String(airData.pm10);
53    postStr +="&field3=";
54    postStr += String(airData.humidity);
55    postStr +="&field4=";
56    postStr += String(airData.temperature);
57    postStr += "\r\n\r\n";
58  
59    client.print("POST /update HTTP/1.1\n");
60    client.print("Host: api.thingspeak.com\n");
61    client.print("Connection: close\n");
62    client.print("X-THINGSPEAKAPIKEY: "+apiKey+"\n");
63    client.print("Content-Type: application/x-www-form-urlencoded\n");
64    client.print("Content-Length: ");
65    client.print(postStr.length());
66    client.print("\n\n");
67    client.print(postStr);
68  }
69  client.stop();
70  delay(15000);
71  
72  server.handleClient();
73}
74
75void connectToWiFi(){
76  WiFi.mode(WIFI_STA);
77  WiFi.begin(ssid, password);
78 
79  Serial.print("Connecting to ");
80  Serial.println(ssid); 
81
82  while (WiFi.status() != WL_CONNECTED) {
83    delay(500);
84    Serial.print(".");
85  }
86
87  Serial.println("");
88  Serial.println("WiFi connected");  
89  Serial.println("IP address: ");
90  Serial.println(WiFi.localIP());
91  startServer();
92}
93
94void startServer(){
95  server.on("/", handleRoot);
96  server.begin();
97  Serial.println("HTTP server started");
98}
99
100void handleRoot() {
101    Air airData = readPolution();
102    server.send(200, "text/plain", "PM2.5: " + String(airData.pm25) + " (" + String(calculatePolutionPM25(airData.pm25)) + "% normy) | PM10: " +  String(airData.pm10) + " (" + String(calculatePolutionPM10(airData.pm10)) + "% normy) | Temperature: " + airData.temperature + " | Humidity: " + airData.humidity);  
103}
104
105Air readPolution(){
106  float temperature, humidity;
107  error = sds.read(&p25,&p10);
108  if (!error) {
109    sensors_event_t event;  
110    dht.temperature().getEvent(&event);
111    if (isnan(event.temperature)) {
112      Serial.println("Error reading temperature!");
113    } else {
114      temperature = event.temperature;
115    }
116  
117    dht.humidity().getEvent(&event);
118    if (isnan(event.relative_humidity)) {
119      Serial.println("Error reading humidity!");
120    } else {
121      humidity = event.relative_humidity;
122    }
123   
124    Air result = (Air){normalizePM25(p25/10, humidity), normalizePM10(p10/10, humidity), humidity, temperature};
125    return result;
126  } else {
127    Serial.println("Error reading SDS011");
128    return (Air){0.0, 0.0, 0.0, 0.0};
129  }
130}
131
132//Correction algorythm thanks to help of Zbyszek Kiliański (Krakow Zdroj)
133float normalizePM25(float pm25, float humidity){
134  return pm25/(1.0+0.48756*pow((humidity/100.0), 8.60068));
135}
136
137float normalizePM10(float pm10, float humidity){
138  return pm10/(1.0+0.81559*pow((humidity/100.0), 5.83411));
139}
140
141float calculatePolutionPM25(float pm25){
142  return pm25*100/25;
143}
144
145float calculatePolutionPM10(float pm10){
146  return pm10*100/50;
147}