Tym razem prezentujemy prosty sposób na monitorowanie temperatury po sieci LAN. Wykorzystujemy standardowo Arduino Uno oraz Ethernet Shield.
Wszystko jest banalnie proste gdyż oprócz arduino potrzebujemy jedynie czujnik DTH11 lub odpowiedniki np. DHT22 (szerszy zakres pomiarowy) oraz rezystor 10kΩ. Ja w tym artykule wykorzystuje czujnik DTH11 gdyż tylko ten mam pod ręką.
Do wykonania będą nam potrzebne następujące elementy:
– Arduino np. Arduino UNO,
– Czujnik wilgotności / temperatury DHT11 lub DHT22,
– Arduino Ethernet Shield
– Rezystor 10 kΩ,
– Kable do połączenia wszystkiego.
Kod programu:
#include <DHT.h>
#define DHTPIN 2
// Uncomment whatever type you’re using!
#define DHTTYPE DHT11 // DHT 11
//#define DHTTYPE DHT22 // DHT 22DHT dht(DHTPIN, DHTTYPE);
#include <SPI.h>
#include <Ethernet.h>// Enter a MAC address and IP address for your controller below.
// The IP address will be dependent on your local network:
byte mac[] = {
0x90, 0xA2, 0xDA, 0x0F, 0x24, 0x14 }; //MAC address found on the back of your ethernet shield.
IPAddress ip(10,10,10,19); // IP address .EthernetServer server(80);
void setup() {
// Open serial communications and wait for port to open:
Serial.begin(9600);
while (!Serial) {
; // wait for serial port to connect. Needed for Leonardo only
}dht.begin();
// start the Ethernet connection and the server:
Ethernet.begin(mac, ip);
server.begin();
Serial.print(„server is at „);
Serial.println(Ethernet.localIP());
}
void loop() {
// Reading temperature or humidity takes about 250 milliseconds!
// Sensor readings may also be up to 2 seconds 'old’ (its a very slow sensor)
float h = dht.readHumidity();
float t = dht.readTemperature();// check if returns are valid, if they are NaN (not a number) then something went wrong!
if (isnan(t) || isnan(h)) {
Serial.println(„Failed to read from DHT”);
} else {
Serial.print(„Humidity: „);
Serial.print(h);
Serial.print(” %\t”);
Serial.print(„Temperature: „);
Serial.print(t);
Serial.println(” *C”);
}// listen for incoming clients
EthernetClient client = server.available();
if (client) {
Serial.println(„new client”);
// an http request ends with a blank line
boolean currentLineIsBlank = true;
while (client.connected()) {
if (client.available()) {
char c = client.read();
Serial.write(c);
// if you’ve gotten to the end of the line (received a newline
// character) and the line is blank, the http request has ended,
// so you can send a reply
if (c == '\n’ && currentLineIsBlank) {
// send a standard http response header
client.println(„HTTP/1.1 200 OK”);
client.println(„Content-Type: text/html”);
client.println(„Connection: close”); // the connection will be closed after completion of the response
client.println(„Refresh: 5”); // refresh the page automatically every 5 sec
client.println();
client.println(„<!DOCTYPE HTML>”);
client.println(„<html>”);// output the value of the DHT-11
client.println(„<H2>”);
client.print(„Humidity: „);
client.println(„</H2>”);
client.println(„<p />”);
client.println(„<H1>”);
client.print(h);
client.print(” %\t”);
client.println(„</H1>”);
client.println(„<p />”);
client.println(„<H2>”);
client.print(„Temperature: „);
client.println(„</H2>”);
client.println(„<H1>”);
//client.print(t*1.8+32); //temp fahrenheit
client.print(t); //temp Celsjusz
client.println(” °”);
//client.println(„F”); //temp fahrenheit
client.println(„C”); //temp celsjusz
client.println(„</H1>”);client.println(„</html>”);
break;
}
if (c == '\n’) {
// you’re starting a new line
currentLineIsBlank = true;
}
else if (c != '\r’) {
// you’ve gotten a character on the current line
currentLineIsBlank = false;
}
}
}
// give the web browser time to receive the data
delay(1);
// close the connection:
client.stop();
Serial.println(„client disonnected”);
}
}