andresrcs/web_server_example.ino

## web_server_example.ino
#include <ESP8266WiFi.h>            // Library for WiFi
#include <ESP8266WebServer.h>       // Library for the web server
#include <ArduinoJson.h>            // Library for JSON processing
#include <OneWire.h>                // Library for DS18B20 sensor
#include <DallasTemperature.h>      // Library for DS18B20 sensor
#include "credentials.h"            // File with WiFi credentials

// Network Configurations
IPAddress ip(192,168,0,102);        // Set the board's IP configuration
IPAddress gateway(192,168,0,1);
IPAddress subnet(255,255,255,0);

// Web Server Configuration
ESP8266WebServer server(80);         //Define web-server on port 80

// DS18B20 Sensor Libraries Configuration
OneWire ourWire(4);                  //Set D2(GPIO-4) pin as OneWire bus
DallasTemperature sensors(&ourWire);

// Global variables definition
float temp0;                         //Define variables to store temp readings
float temp1;
float temp2;
unsigned long previousMillis = 0;    //Temporal variable
const long interval = 2000;          //Set minimal interval between readings

void setup() {
    Serial.begin(115200);
    delay(10);

    // Connect to WiFi network
    Serial.println(); Serial.println();
    Serial.print("Connecting to ");
    Serial.println(WLAN_SSID);

    WiFi.config(ip, gateway, subnet);
    WiFi.mode(WIFI_STA);
    WiFi.begin(WLAN_SSID, WLAN_PASSWORD);
    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
    }

    Serial.println();
    Serial.println("WiFi connected");
    Serial.println("IP address: ");
    Serial.println(WiFi.localIP());

    sensors.begin();                      // Initialize DS18B20 sensors

    // Define server responses
    server.on("/reading", HTTP_GET, [](){
        read_sensor();

        char buff0[9];                    //Define character buffer variables to store converted values
        char buff1[9];
        char buff2[9];
        dtostrf(temp0, 8, 4, buff0);      //Convert float values to string for printing 7 character + sign + NULL
        dtostrf(temp1, 8, 4, buff1);
        dtostrf(temp2, 8, 4, buff2);

        char webString[600];              //Define character variable for storing the HTML page
        snprintf(webString, 600,          //Write HTML page
"\
<html>\
  <head>\
    <meta http-equiv='refresh' content='5'/>\
    <title>DS18B20 Server</title>\
    <style>\
      body { background-color: #cccccc; font-family: Arial, Helvetica, Sans-Serif; Color: #000088; }\
    </style>\
  </head>\
  <body>\
    <h1>Sensor Data</h1>\
    <p>Temperature 01: %s &#176;C</p>\
    <p>Temperature 02: %s &#176;C</p>\
    <p>Temperature 03: %s &#176;C</p>\
  </body>\
</html>\
", buff0, buff1, buff2);
        // Log to serial monitor
        Serial.println();
        Serial.println("Reporting Temp(0) " + String((int)temp0) + F(" °C"));
        Serial.println("Reporting Temp(1) " + String((int)temp1) + F(" °C"));
        Serial.println("Reporting Temp(2) " + String((int)temp2) + F(" °C"));
        // Send response
        server.send(200, "text/html", webString);
    });

    server.on("/reading.json", [](){
        read_sensor();

        StaticJsonDocument<500> jsonBuffer;             //Create JSON document
        JsonObject root = jsonBuffer.to<JsonObject>();  //Create JSON object
        root["temperature-probe0"] = temp0;             //Add values to elements
        root["temperature-probe1"] = temp1;
        root["temperature-probe2"] = temp2;

        String jsonString;
        serializeJson(jsonBuffer, jsonString);          //Serialize JSON for printing

        // Log to serial monitor
        Serial.println();
        Serial.println(jsonString);
        // Send response
        server.send(200, "application/json", jsonString);
    });

    server.begin();   //Start server
    Serial.println("Temp server started! Waiting for clients!");
    digitalWrite(LED_BUILTIN, HIGH);    //Turn the LED off
}

void loop() {
    server.handleClient();
}

// Get sensor readings
void read_sensor() {
    unsigned long currentMillis = millis();
    if (currentMillis - previousMillis >= interval) {
        previousMillis = currentMillis;

        sensors.requestTemperatures();         //Request temp readings
        temp0 = sensors.getTempCByIndex(0);    //Request temp in C by index
        temp1 = sensors.getTempCByIndex(1);
        temp2 = sensors.getTempCByIndex(2);

        if (isnan(temp0) | isnan(temp1) | isnan(temp2)) {
            Serial.println("Failed to read from DS18B20 sensors!");
            return;
        }
    }
}
	#include <ESP8266WiFi.h> // Library for WiFi
	#include <ESP8266WebServer.h> // Library for the web server
	#include <ArduinoJson.h> // Library for JSON processing
	#include <OneWire.h> // Library for DS18B20 sensor
	#include <DallasTemperature.h> // Library for DS18B20 sensor
	#include "credentials.h" // File with WiFi credentials

	// Network Configurations
	IPAddress ip(192,168,0,102); // Set the board's IP configuration
	IPAddress gateway(192,168,0,1);
	IPAddress subnet(255,255,255,0);

	// Web Server Configuration
	ESP8266WebServer server(80); //Define web-server on port 80

	// DS18B20 Sensor Libraries Configuration
	OneWire ourWire(4); //Set D2(GPIO-4) pin as OneWire bus
	DallasTemperature sensors(&ourWire);

	// Global variables definition
	float temp0; //Define variables to store temp readings
	float temp1;
	float temp2;
	unsigned long previousMillis = 0; //Temporal variable
	const long interval = 2000; //Set minimal interval between readings

	void setup() {
	Serial.begin(115200);
	delay(10);

	// Connect to WiFi network
	Serial.println(); Serial.println();
	Serial.print("Connecting to ");
	Serial.println(WLAN_SSID);

	WiFi.config(ip, gateway, subnet);
	WiFi.mode(WIFI_STA);
	WiFi.begin(WLAN_SSID, WLAN_PASSWORD);
	while (WiFi.status() != WL_CONNECTED) {
	delay(500);
	Serial.print(".");
	}

	Serial.println();
	Serial.println("WiFi connected");
	Serial.println("IP address: ");
	Serial.println(WiFi.localIP());

	sensors.begin(); // Initialize DS18B20 sensors

	// Define server responses
	server.on("/reading", HTTP_GET, [](){
	read_sensor();

	char buff0[9]; //Define character buffer variables to store converted values
	char buff1[9];
	char buff2[9];
	dtostrf(temp0, 8, 4, buff0); //Convert float values to string for printing 7 character + sign + NULL
	dtostrf(temp1, 8, 4, buff1);
	dtostrf(temp2, 8, 4, buff2);

	char webString[600]; //Define character variable for storing the HTML page
	snprintf(webString, 600, //Write HTML page
	"\
	<html>\
	<head>\
	<meta http-equiv='refresh' content='5'/>\
	<title>DS18B20 Server</title>\
	<style>\
	body { background-color: #cccccc; font-family: Arial, Helvetica, Sans-Serif; Color: #000088; }\
	</style>\
	</head>\
	<body>\
	<h1>Sensor Data</h1>\
	<p>Temperature 01: %s °C</p>\
	<p>Temperature 02: %s °C</p>\
	<p>Temperature 03: %s °C</p>\
	</body>\
	</html>\
	", buff0, buff1, buff2);
	// Log to serial monitor
	Serial.println();
	Serial.println("Reporting Temp(0) " + String((int)temp0) + F(" °C"));
	Serial.println("Reporting Temp(1) " + String((int)temp1) + F(" °C"));
	Serial.println("Reporting Temp(2) " + String((int)temp2) + F(" °C"));
	// Send response
	server.send(200, "text/html", webString);
	});

	server.on("/reading.json", [](){
	read_sensor();

	StaticJsonDocument<500> jsonBuffer; //Create JSON document
	JsonObject root = jsonBuffer.to<JsonObject>(); //Create JSON object
	root["temperature-probe0"] = temp0; //Add values to elements
	root["temperature-probe1"] = temp1;
	root["temperature-probe2"] = temp2;

	String jsonString;
	serializeJson(jsonBuffer, jsonString); //Serialize JSON for printing

	// Log to serial monitor
	Serial.println();
	Serial.println(jsonString);
	// Send response
	server.send(200, "application/json", jsonString);
	});

	server.begin(); //Start server
	Serial.println("Temp server started! Waiting for clients!");
	digitalWrite(LED_BUILTIN, HIGH); //Turn the LED off
	}

	void loop() {
	server.handleClient();
	}

	// Get sensor readings
	void read_sensor() {
	unsigned long currentMillis = millis();
	if (currentMillis - previousMillis >= interval) {
	previousMillis = currentMillis;

	sensors.requestTemperatures(); //Request temp readings
	temp0 = sensors.getTempCByIndex(0); //Request temp in C by index
	temp1 = sensors.getTempCByIndex(1);
	temp2 = sensors.getTempCByIndex(2);

	if (isnan(temp0) \| isnan(temp1) \| isnan(temp2)) {
	Serial.println("Failed to read from DS18B20 sensors!");
	return;
	}
	}
	}