Get current weather data from OpenWeatherMap.org

[Jack Kim]

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"};

#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());
}