TestJson.h

// password of your WiFi network.
#define mySSID "513570"
#define myPSK "H21208269B2B"

// openweathermap Constants
#define HTTP_PORT 80
#define WEATHER_SERVER  "api.openweathermap.org"
#define ID_CITY "4019233"
#define APP_ID  "44db6a862fba0b067b1930da0d769e98"

#define HTTP_HEADER  "GET /data/2.5/weather?id=" ID_CITY \
                    "&appid=" APP_ID "&units=metric" " HTTP/1.1\r\n" \
                    "Host: " WEATHER_SERVER "\r\n" \
                    "Content-Type: application/x-www-form-urlencoded\r\n" \
                    "Connection: close\r\n\r\n"

TestJson.ino

#include <SoftwareSerial.h>
#include <SparkFunESP8266WiFi.h>
#include <avr/pgmspace.h>
#include <Servo.h>
#include <json_arduino.h>

#include "sabas.h"

Servo myservo;
ESP8266Client client;

char json_string[512];
token_list_t *token_list = NULL;
// "{\"coord\":{\"lon\":-102.3,\"lat\":21.88},\"weather\":[{\"id\":800,\"main\":\"Clear\",\"description\":\"sky is clear\",\"icon\":\"02n\"}],\"base\":\"cmc stations\",\"main\":{\"temp\":5,\"pressure\":1025,\"humidity\":56,\"temp_min\":5,\"temp_max\":5},\"wind\":{\"speed\":7.7,\"deg\":20},\"clouds\":{\"all\":5},\"dt\":1453956180,\"sys\":{\"type\":1,\"id\":3966,\"message\":0.0026,\"country\":\"MX\",\"sunrise\":1453987717,\"sunset\":1454027754},\"id\":4019233,\"name\":\"Aguascalientes\",\"cod\":200}"

void setup()
{
  int status;
  Serial.begin(9600);
  myservo.attach(3);  // attaches the servo on pin 5 to the servo object

  // To turn the MG2639 shield on, and verify communication
  // always begin a sketch by calling cell.begin().
  status = esp8266.begin();
  if (status <= 0)
  {
    Serial.println(F("Unable to communicate with shield. Looping"));
    while(1) ;
  }

  esp8266.setMode(ESP8266_MODE_STA); // Set WiFi mode to station
  if (esp8266.status() <= 0) // If we're not already connected
  {
    if (esp8266.connect(mySSID, myPSK) < 0)
    {
      Serial.println(F("Error connecting"));
      while (1) ;
    }
  }

  // Get our assigned IP address and print it:
  Serial.print(F("My IP address is: "));
  Serial.println(esp8266.localIP());

  Serial.println(F("Press any key to post to IFTTT!"));
}

void loop()
{
  // If a character has been received over serial:
  if (Serial.available())
  {
    // !!! Make sure we haven't posted recently
    // Post to IFTTT!
    getData();
    // Then clear the serial buffer:
    while (Serial.available())
      Serial.read();
  }
}

void getData()
{

  if (client.connect(WEATHER_SERVER, HTTP_PORT) <= 0)
  {
    Serial.println(F("Failed to connect to server."));
    return;
  }

  Serial.println(F("Connected."));
  client.print(F(HTTP_HEADER));

  // read response
  while(client.available()){
    client.readStringUntil('\r').toCharArray(json_string, 512);
    // Serial.print(json_string);
  }

  if (client.connected()) client.stop();
}