Get Current Weather Data from OpenWeatherMap.org

Get current weather data for any city on Earth from OpenWeatherMap.org.

IntermediateFull instructions provided24 hours19,464

Get Current Weather Data from OpenWeatherMap.org

Things used in this project

Hardware components

PHPoC WiFi Shield for Arduino

Arduino Mega 2560

MDP070N RS232 COLOR LCD

Software apps and online services

OpenWeatherMap.org

Story

1. Project

Get current weather data for any city on Earth from OpenWeatherMap.org

2. Product

PHPoC WiFi Shield for Arduino (P4S-347)

Arduino MEGA2560

MDP070N Color LCD.

3. How it works

OpenWeatherMap.org gives current weather data us for free.

Refer to the link below for detail information of price plan. http://openweathermap.org/price

You have to sign up and create API key to get current weather data.

Data is in JSON, XML, or HTML format. In this project, I use JSON format.

4. Source code

"YOUR_API_KEY" should be replaced your own API key.

List city names in cityNames array variable.

E.g. char *cityNames[] = {"barcelona, es", "paris", "new york", "sydney", "london"};

OpenWeatherMap.ino

#include <Arduino.h>
#include <Phpoc.h>
#include <SPI.h>
#include "Timer.h"

#include <ArduinoJson.h>

static PhpocClient phpocClient;

#define INTERVAL 4000

#define HTTP_QUERY_SIZE 1400
uint8_t httpQuery[HTTP_QUERY_SIZE];

int BUTTON_GPIO = 3;

char *server = "api.openweathermap.org";
char *apiKey = "YOUR_API_KEY";
char *cityNames[] = {"CITY_NAME,COUNTRY_CODE"};
char *currentWeather = "GET /data/2.5/weather?";

// Group 2xx: Thunderstorm  weather5.png
// Group 3xx: Drizzle  weather5.png
// Group 5xx: Rain  weather5.png

// Group 6xx: Snow  weather7.png

// Group 7xx: Atmosphere(안개)  weather2.png

// Group 800: CLEAR SKY. weather1.png

// Group 801: FEW CLOUDS. weather4.png
// Group 802: SCATTERED CLOUDS. weather2.png
// Group 803: BROKEN CLOUDS. weather3.png
// Group 804: OVERCAST CLOUDS. weather3.png

uint16_t queryLength = 0;
bool isRunning = false;
String httpResponse = "";
int numberOfCity = 0;

void setup() {
  // put your setup code here, to run once:  
  Serial.begin(115200);
  while (!Serial);// wait for serial port to connect.
  Serial.println();

  Serial1.begin(115200);
  while (!Serial1);// wait for serial port to connect.

  sendCmd("Clear\r\n");
  sendCmd("LoadFont \"/unbatang.ttf\"\r\n");

  Phpoc.begin(PF_LOG_SPI | PF_LOG_NET);
  Serial.println(Phpoc.localIP());

  numberOfCity = sizeof(cityNames) / sizeof(char*);
  
  // LCD
  initLCD();
}

void loop() {  
  // put your main code here, to run repeatedly:  
  apiLoop();
  httpLoop();
}

void apiLoop()
{
  static int index = 0;
  static unsigned long prevMills = 0;
  bool callApi = false;

  unsigned long currentMills = millis();
  if(prevMills == 0 || (currentMills - prevMills >= INTERVAL))
  {
    prevMills = currentMills;
    callApi = true;
  }

  if(callApi)
  {
    queryLength = getQueryCurrentWeather(httpQuery, cityNames[index++], apiKey);
    if(index >= numberOfCity)
      index = 0;
      
    httpResponse = "";
    if(phpocClient.connect(server, 80))
    {
      isRunning = true;
      phpocClient.write(httpQuery, queryLength);
    }
  }
}

char buf[1024];
String f = "\r\n\r\n";
void httpLoop()
{
  if(isRunning)  
  {
    uint16_t cnt = phpocClient.available();
    if(cnt > 0)
    {
      uint8_t tryRead = cnt > 128 ? 128 : cnt;
      memset(buf, 0, 1024);
      uint16_t recv = phpocClient.read(buf, tryRead);
      
      httpResponse = httpResponse + buf;      
      
      int idx = httpResponse.lastIndexOf(f);
      if(idx >= 0)
        httpResponse = httpResponse.substring(idx + 4);
    }
    
    if(!phpocClient.connected())
    {
      isRunning = false;
      sendCmd("DisableFlush");
      
      //----------------------------------------
      // JSON
      Serial.println(httpResponse.c_str());
      
      DynamicJsonBuffer jsonBuffer;
      JsonObject& root = jsonBuffer.parseObject(httpResponse);
      if(!root.success())
      {
        Serial.println("parseObject failed.");
        phpocClient.stop();
        isRunning = false;
        return;
      }
      
      uint16_t resultCode = root["cod"];
      Serial.println(resultCode);
      if(resultCode == 200)
      {
        //
        JsonObject& weather = root["weather"][0];
        String weatherId = weather["id"]; 
        String cityName = root["name"]; 
        double temperature = root["main"]["temp"]; 
        String temp = String(lround(temperature));
        String humidity = root["main"]["humidity"]; 
        String weatherDesc = weather["description"]; 

        printIcon(weatherId);
        printCity(cityName);
        printTemperature(temp);
        printHumidity(humidity);
        printWeather(weatherDesc);
        
        hidePopup();
      
        sendCmd("EnableLayer 1");
        sendCmd("EnableLayer 2");
        sendCmd("EnableLayer 3");
        sendCmd("EnableLayer 4");
        sendCmd("EnableLayer 5");
      }
      else
      {
        // fail.
      }
      //----------------------------------------
      
      Serial.println("disconnected");
      phpocClient.stop();
      sendCmd("EnableFlush");
    }
  }
}

uint16_t writeString(const char* string, uint8_t* buf, uint16_t pos) 
{
    const char* idp = string;
    uint16_t i = 0;
 
    while (*idp) 
    {
        buf[pos++] = *idp++;
        i++;
    }
    
    return pos;
}

uint16_t getQueryCurrentWeather(uint8_t* query, char* cityName, char* apiKey)
{
  uint16_t queryLength = 0;

  queryLength = writeString(currentWeather, query, queryLength);
  queryLength = writeString("q=", query, queryLength);
  queryLength = writeString(cityName, query, queryLength);
  queryLength = writeString("&units=metric&appid=", httpQuery, queryLength);
  queryLength = writeString(apiKey, query, queryLength);  

  queryLength = writeString(" HTTP/1.1\r\nHost: api.openweathermap.org\r\n", query, queryLength);
  queryLength = writeString("Connection: Closed\r\n\r\n", query, queryLength);
  
  return queryLength;
}

void sendCmd(char* cmd)
{
  Serial1.println(cmd);
}

void initLCD()
{
  sendCmd("Layer 0");
  sendCmd("Clear");
  //sendCmd("LoadFont \"/unbatang.ttf\"");

  sendCmd("DestroyLayer 1");
  sendCmd("DestroyLayer 2");
  sendCmd("DestroyLayer 3");
  sendCmd("DestroyLayer 4");
  sendCmd("DestroyLayer 5");
  sendCmd("DestroyLayer 6");
  sendCmd("DestroyLayer 7");
  sendCmd("DestroyLayer 8");
  sendCmd("DestroyLayer 9");
  sendCmd("DestroyLayer 10");
  sendCmd("DestroyLayer 11");
  sendCmd("DestroyLayer 12");
  sendCmd("DestroyLayer 13");

  createLayers();
  createPopup();

  showPopup("Loading...");

  sendCmd("DisableFlush");
  sendCmd("Layer 0");
  sendCmd("FontSize 48");  
  sendCmd("Image 0 0 \"/image/bk3.png\"");
  sendCmd("EnableFlush");
}

void createLayers()
{
  // weather condition
  sendCmd("CreateLayer 68 380 732 70 1");  
  // ICON
  sendCmd("CreateLayer 68 108 265 245 2");
  // City name
  sendCmd("CreateLayer 460 60 320 80 3");
  // Temperature
  sendCmd("CreateLayer 460 170 340 120 4");
  // Humidity
  sendCmd("CreateLayer 460 310 340 70 5");
}

void createPopup()
{  
  sendCmd("CreateLayer 80 180 640 120 6");
  sendCmd("Layer 6");
  sendCmd("DisableLayer 6");
}

void showPopup(String msg)
{
  String cmd;
  sendCmd("Layer 6");
  sendCmd("Clear");
  sendCmd("FontSize 72");
  sendCmd("Color FFFFFF");
  cmd = "Button 0 0 640 120 10 336699 336699 \"" + msg + "\"";
  sendCmd(cmd.c_str());
  sendCmd("EnableLayer 6");
}

void hidePopup()
{
  sendCmd("DisableLayer 6");
}

void printCity(String cityName)
{
  String cmd;
  sendCmd("Layer 3");
  sendCmd("DisableLayer 3");
  sendCmd("Clear");
  sendCmd("FontSize 60");
  sendCmd("Color FFFFFF");
  cmd = "FillText 0 60 \""; cmd = cmd + cityName + "\"";
  sendCmd(cmd.c_str());
}

void printTemperature(String temperature)
{
  String cmd;
  sendCmd("Layer 4");
  sendCmd("DisableLayer 4");
  sendCmd("Clear");
  sendCmd("FontSize 100");
  sendCmd("Color FFFFFF");
  cmd = "FillText 0 90 \""; cmd = cmd + temperature + "℃\"";
  sendCmd(cmd.c_str());
}

void printHumidity(String humidity)
{
  String cmd;
  sendCmd("Layer 5");
  sendCmd("DisableLayer 5");
  sendCmd("Clear");
  sendCmd("FontSize 48");
  sendCmd("Color FFFFFF");
  cmd = "FillText 0 50 \""; cmd = cmd + humidity + "%\"";
  sendCmd(cmd.c_str());
}

void printIcon(String id)
{
  sendCmd("Layer 2");
  sendCmd("DisableLayer 2");
  sendCmd("Clear");
  
  String cmd, icon;
  char code = id.charAt(0);
  switch(code)
  {
    case '2':
    case '3':
    case '5':
      icon = "/image/weather5.png";
      break;
    case '6':
      icon = "/image/weather7.png";
      break;
    case '7':
      icon = "/image/weather2.png";
      break;
     case '8':
      if(id.equals("800"))
        icon = "/image/weather1.png";
      else if(id.equals("801"))
        icon = "/image/weather4.png";
      else if(id.equals("802"))
        icon = "/image/weather2.png";
      else if(id.equals("803"))
        icon = "/image/weather3.png";
      else if(id.equals("804"))
        icon = "/image/weather3.png";
      break;
  }

  cmd = "Image 0 0 \"" + icon + "\"";
  sendCmd(cmd.c_str());
}

void printWeather(String weather)
{
  String cmd;
  sendCmd("Layer 1");
  sendCmd("DisableLayer 1");
  sendCmd("Clear");
  sendCmd("FontSize 48");
  sendCmd("Color FFFFFF");
  weather.toUpperCase();
  cmd = "FillText 0 50 \""; cmd = cmd + weather + "\"";
  //sendCmd(cmd.c_str());
}

Get Current Weather Data from OpenWeatherMap.org