ethernet dht22

ethernet_DHT22.ino

#include <DHT.h>

#include "ArduinoJson.h"
#define DHTTYPE DHT22
#define DHTPIN 7
//#include <Dhcp.h>
#include <Ethernet.h>
#include <EthernetClient.h>
#include <EthernetServer.h>
// #include <msgpck.h>

#include <CRC32.h>

#define SEA_LEVEL_PRESSURE  1013.25f

DHT dht(DHTPIN, DHTTYPE);

float temp, hum, es, ea, vpd, ah_kgm3, ah_gm3;

byte mac[] = {
  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
};
IPAddress ip(192, 168, 1, 100);
EthernetServer server(80);
const size_t bufferSize = JSON_OBJECT_SIZE(10);

void setup() {
  Serial.begin(9600);
  Serial.println("Startup...");
  dht.begin();
  // start the Ethernet connection and the server:
  Ethernet.begin(mac, ip);
  server.begin();
  Serial.println("server live");
  Serial.println(Ethernet.localIP());
 
}

void loop() {
  // The sensor can only be read from every 1-2s, and requires a minimum
  // 2s warm-up after power-on.
  
  EthernetClient client = server.available();
  if (client) {
    boolean currentLineIsBlank = true;
    while (client.connected()) {
      
      if (client.available()) {
        char c = client.read();
        
        if (c == '\n' && currentLineIsBlank) {
          Serial.println("new client");
          client.println("HTTP/1.1 200 OK");
          client.println("Content-Type: application/json");
          client.println("Connection: close");  // the connection will be closed after completion of the response
          client.println();
          delay(2000); 
          temp = dht.readTemperature();
          hum = dht.readHumidity();
                
            // saturated vapor pressure
            es = 0.6108 * exp(17.27 * temp / (temp + 237.3));
  
            // actual vapor pressure
            ea = hum / 100.0 * es;
  
            // this equation returns a negative value (in kPa), which while technically correct,
            // is invalid in this case because we are talking about a deficit.
            vpd = (ea - es) * -1;
  
            // mixing ratio
            //w = 621.97 * ea / ((pressure64/10) - ea);
            // saturated mixing ratio
            //ws = 621.97 * es / ((pressure64/10) - es);
  
            // absolute humidity (in kg/m³)
            ah_kgm3 = es / (461.5 * (temp + 273.15));
            // report it as g/m³
            ah_gm3 = ah_kgm3 * 1000;
            CRC32 crc;
  
            float values[] = { temp, hum, es, ea, vpd, ah_gm3 };
            for ( byte i = 0; i  < 6; i++) {
              crc.update(values[i]);
            }
  
            
            DynamicJsonBuffer jsonBuffer(bufferSize);
            
            JsonObject& root = jsonBuffer.createObject();
            root["temp_c"] = temp;
            root["hum_rh"] = hum;
            root["es_kPa"] = es;
            root["ea_kPa"] = ea;
            root["vpd_kPa"] = vpd;
            root["ah_gm3"] = ah_gm3;
            root["crc32"] = int(crc.finalize());
            root["host"] = "sensor01";
            
            root.prettyPrintTo(client);
            break;
            


//          msgpck_write_map_header(&client, 9);
//          msgpck_write_string(&client, "temp_c");
//          msgpck_write_float(&client, temp);
//          msgpck_write_string(&client, "hum_rh");
//          msgpck_write_float(&client, hum);
//          msgpck_write_string(&client, "pa_p");
//          msgpck_write_float(&client, pa);
//          msgpck_write_string(&client, "alt_m");
//          msgpck_write_float(&client, alt);
//
//          msgpck_write_string(&client, "es_kPa");
//          msgpck_write_float(&client, es);
//          msgpck_write_string(&client, "ea_kPa");
//          msgpck_write_float(&client, ea);
//          msgpck_write_string(&client, "vpd_kPa");
//          msgpck_write_float(&client, vpd);
//          msgpck_write_string(&client, "ah_gm3");
//          msgpck_write_float(&client, ah_gm3);
//
//          msgpck_write_string(&client, "crc32");
//          msgpck_write_integer(&client, crc.finalize());
          break;
        }

        if (c == '\n') {
          currentLineIsBlank = true;
        } else if (c != '\r') {
          // you've gotten a character on the current line
          currentLineIsBlank = false;
        }
      }
    }
    delay(1);
    client.stop();
  }
}