Getting weather data

What we want to get from the query result is just the weather of the next 3 forecast. To get the data we will have to go through the Json tree looking for what we need.

For instance, to get the “list” property of the json.

data[“list”]

To get the first element of the list we can get

data[“list”][0]

To get the weather forecast we should get

data[“list”][0][“weather”]

This returns an array, therefore we need to ask for the first element of the list

data[“list”][0][“weather”][0]

this will return a series of values like temperature weather description etc…

data[“list”][0][“weather”][0][“main”]

getting the main value will return the actual weather forecast in plain words (sun, rain, snow etc…)

Look at the code provided below, it mast be clear at this point how you can get the necessary data from open weather map for your project.

Get the code here

#include <ArduinoJson.h> 
#include <SPI.h> 
#include <WiFi101.h> 
char ssid[] = SECRET_SSID; //  your network SSID (name) 
char pass[] = SECRET_PSW;//  your network PASSWORD () 
//open weather map api key 
String apiKey= SECRET_APIKEY; 
//the city you want the weather for 
String location= "torino,IT"; 
int status = WL_IDLE_STATUS; 
char server[] = "api.openweathermap.org";     
WiFiClient client; 
void setup() { 
 //Initialize serial and wait for port to open: 
 Serial.begin(9600); 
 // attempt to connect to Wifi network: 
 while (status != WL_CONNECTED) { 
   Serial.print("Attempting to connect to SSID: "); 
   Serial.println(ssid); 
   status = WiFi.begin(ssid); 
   //use the line below if your network is protected by wpa password  
   //status = WiFi.begin(ssid, pass); 
   // wait 10 seconds for connection: 
   delay(1000); 
 } 
 Serial.println("Connected to wifi"); 
} 
void loop() { 
 getWeather(); 
 delay(10000); 
} 
void getWeather() { 
 Serial.println("\nStarting connection to server..."); 
 // if you get a connection, report back via serial: 
 if (client.connect(server, 80)) { 
   Serial.println("connected to server"); 
   // Make a HTTP request: 
   client.print("GET /data/2.5/forecast?"); 
   client.print("q="+location); 
   client.print("&appid="+apiKey); 
   client.print("&cnt=3"); 
   client.println("&units=metric"); 
   client.println("Host: api.openweathermap.org"); 
   client.println("Connection: close"); 
   client.println(); 
 } else { 
   Serial.println("unable to connect"); 
 } 
 delay(1000); 
 String line = ""; 
 while (client.connected()) { 
   line = client.readStringUntil('\n'); 
   //Serial.println(line); 
   Serial.println("parsingValues"); 
   //create a json buffer where to store the json data 
   StaticJsonBuffer<5000> jsonBuffer; 
   JsonObject& root = jsonBuffer.parseObject(line); 
   if (!root.success()) { 
     Serial.println("parseObject() failed"); 
     return; 
   } 
 //get the data from the json tree 
 String nextWeatherTime0 = root["list"][0]["dt_txt"]; 
 String nextWeather0 = root["list"][0]["weather"][0]["main"]; 
 String nextWeatherTime1 = root["list"][1]["dt_txt"]; 
 String nextWeather1 = root["list"][1]["weather"][0]["main"]; 
 String nextWeatherTime2 = root["list"][2]["dt_txt"]; 
 String nextWeather2 = root["list"][2]["weather"][0]["main"]; 
 // Print values. 
 Serial.println(nextWeatherTime0); 
 Serial.println(nextWeather0); 
 Serial.println(nextWeatherTime1); 
 Serial.println(nextWeather1);   
 Serial.println(nextWeatherTime2); 
 Serial.println(nextWeather2); 
 } 
}