added weather forecast fetch from open-meteo

include/screens.h

@@ -5,6 +5,7 @@
 
 #include "am2302_sensor.h"
 #include "internet_time.h"
+#include "weather_forecast.h"
 #include "wifi_connection.h"
 
 void setInternetTimeInfo(InternetTimeInfo timeInfo);
@@ -13,6 +14,7 @@ void drawHelloWorldScreen(U8G2 &u8g2);
 void drawInternetConnectionScreen(U8G2 &u8g2, WifiConnectionInfo wifiInfo);
 void setEnvironmentReading(Am2302Reading reading);
 void drawEnvironmentScreen(U8G2 &u8g2);
-void drawWeatherIconScreen(U8G2 &u8g2);
+void setWeatherForecastInfo(WeatherForecastInfo forecastInfo);
+void drawWeatherForecastScreen(U8G2 &u8g2);
 
 #endif

include/weather_forecast.h

@@ -0,0 +1,37 @@
+#ifndef WEATHER_FORECAST_H
+#define WEATHER_FORECAST_H
+
+#include <Arduino.h>
+
+struct WeatherForecastInfo
+{
+  bool valid;
+  float currentTemperatureC;
+  float minTemperatureC;
+  float maxTemperatureC;
+  float precipitationMm;
+  uint8_t precipitationProbabilityPercent;
+  int weatherCode;
+};
+
+class WeatherForecast
+{
+public:
+  WeatherForecast();
+  void update(unsigned long now, bool wifiConnected);
+  WeatherForecastInfo info() const;
+  bool consumeDirty();
+
+private:
+  void fetch(unsigned long now);
+  bool readResponse(String &body);
+  bool parseForecast(const String &body, WeatherForecastInfo &forecast) const;
+  bool parseFloatArray(const String &body, const char *name, float *values, size_t maxCount, size_t &count) const;
+  bool parseIntArray(const String &body, const char *name, int *values, size_t maxCount, size_t &count) const;
+
+  WeatherForecastInfo current_;
+  unsigned long nextAttempt_;
+  bool dirty_;
+};
+
+#endif

include/wifi_credentials.example.h

@@ -7,4 +7,8 @@ const char WIFI_PASSWORD[] = "your-wifi-password";
 // Offset from UTC in seconds. Examples: Finland winter 7200, Finland summer 10800.
 #define TIME_UTC_OFFSET_SECONDS 0
 
+// Coordinates used for the weather forecast.
+#define WEATHER_LATITUDE 60.1699
+#define WEATHER_LONGITUDE 24.9384
+
 #endif