add current weather and forecast

2 files changed, 231 insertions, 2 deletions

diff --git a/src/main.cpp b/src/main.cpp
index ee7435a..c987f92 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -4,6 +4,7 @@
 
 #include "calendar.h"
 #include "draw_qrcode.h"
+#include "weather.h"
 #include "secrets.h"
 
 /*
@@ -48,8 +49,9 @@ void draw() {
 
 	do {
 		display.fillScreen(GxEPD_WHITE);
-		draw_calendar(30, 30);
-		draw_qrcode_wlan(30, 200, wifi_ssid, wifi_psk);
+		draw_calendar(30, 10);
+		draw_weather(10, 180);
+		//draw_qrcode_wlan(30, 200, wifi_ssid, wifi_psk);
 	} while(display.nextPage());
 }
 
@@ -76,6 +78,7 @@ void setup() {
 
 	wifi_connect();
 	update_time();
+	fetch_weather();
 	wifi_disconnect();
 
 	display_setup();
diff --git a/src/weather.cpp b/src/weather.cpp
new file mode 100644
index 0000000..e38e44f
--- /dev/null
+++ b/src/weather.cpp
@@ -0,0 +1,226 @@
+#include <GxEPD2_BW.h>
+#include <U8g2_for_Adafruit_GFX.h>
+#include <HTTPClient.h>
+#include <ArduinoJson.h>
+
+#include "weather-icons.h"
+#include "secrets.h"
+
+/* Position for Durlach */
+#define lat 48.999
+#define lon  8.474
+
+#define FONTSIZE 10
+#define SPACING 5
+
+#define DIM(w, h) (((w) << 16) | (h))
+#define GETW(dim) ((dim) >> 16)
+#define GETH(dim) ((dim) & 0xffff)
+
+extern GxEPD2_GFX_BASE_CLASS &get_display();
+extern U8G2_FOR_ADAFRUIT_GFX u8g2Fonts;
+
+static StaticJsonDocument<16000> weather_json;
+static DeserializationError json_state = DeserializationError::IncompleteInput;
+
+void fetch_weather() {
+	/* use HTTP intentionally for simplicity
+	   don't use on insecure networks */
+	String url = "http://api.openweathermap.org/data/2.5/onecall?units=metric&lang=de&exclude=minutely,hourly";
+	url += "&appid=" + String(openweathermap_apikey);
+	url += "&lat=" + String(lat);
+	url += "&lon=" + String(lon);
+
+	HTTPClient http;
+	http.begin(url);
+	int status = http.GET();
+
+	String weather_info = "";
+	if (status == HTTP_CODE_OK) {
+		weather_info = http.getString();
+	} else {
+		Serial.println("http error\r\n");
+	}
+	http.end();
+	json_state = deserializeJson(weather_json, weather_info);
+	if (json_state != DeserializationError::Ok) {
+		Serial.println("json deserialization error\r\n");
+	}
+}
+
+static uint32_t draw_icon(int16_t x, int16_t y, const unsigned char *image, uint16_t width, uint16_t height) {
+	get_display().drawXBitmap(x, y, image, width, height, GxEPD_BLACK);
+	return DIM(width, height);
+}
+
+static uint32_t draw_weather_icon(int16_t x, int16_t y, int code) {
+	const unsigned char *image = NULL;
+	uint16_t width = 0, height = 0;
+
+	int icon_group = code / 100;
+	switch (icon_group) {
+		case 2:
+			image = thunderstorm_bits;
+			width = thunderstorm_width;
+			height = thunderstorm_height;
+			break;
+		case 3:
+		case 5:
+			image = rain_bits;
+			width = rain_width;
+			height = rain_height;
+			break;
+		case 6:
+			image = snow_bits;
+			width = snow_width;
+			height = snow_height;
+			break;
+		case 7:
+			image = fog_bits;
+			width = fog_width;
+			height = fog_height;
+			break;
+		case 8:
+			image = cloudy_bits;
+			width = cloudy_width;
+			height = cloudy_height;
+			break;
+	}
+	if (code == 800 || !image) {
+		/* special case, clear sky / no clouds */
+		image = sunny_bits;
+		width = sunny_width;
+		height = sunny_height;
+	}
+
+	return draw_icon(x, y, image, width, height);
+}
+
+static uint32_t draw_temperature(int16_t x, int16_t y, float temp, float temp_max = 0.0) {
+	uint16_t w = thermometer_width, h = thermometer_height;
+	int text_width = 0;
+	draw_icon(x, y, thermometer_bits, w, h);
+	u8g2Fonts.setCursor(x + w + SPACING, y + h/2 + FONTSIZE/2);
+	if (temp_max > 0) {
+		u8g2Fonts.printf("%.1f - %.1f °C", temp, temp_max);
+		text_width = u8g2Fonts.getUTF8Width("88.8 - 88.8 °C");
+	} else {
+		u8g2Fonts.printf("%.1f °C", temp);
+		text_width = u8g2Fonts.getUTF8Width("88.8 °C");
+	}
+
+	return DIM(w + SPACING + text_width, h);
+}
+
+static uint32_t draw_humidity(int16_t x, int16_t y, int humidity) {
+	uint16_t w = humidity_width, h = humidity_height;
+	draw_icon(x, y, humidity_bits, w, h);
+	u8g2Fonts.setCursor(x + w + SPACING, y + h/2 + FONTSIZE/2);
+	u8g2Fonts.printf("%d %%", humidity);
+
+	return DIM(w, h);
+}
+
+static uint32_t draw_rain_prob(int16_t x, int16_t y, uint8_t rain) {
+	uint16_t w = raindrops_width, h = raindrops_width;
+	draw_icon(x, y, raindrops_bits, w, h);
+	u8g2Fonts.setCursor(x + w + SPACING, y + h/2 + FONTSIZE/2);
+	u8g2Fonts.printf("%d %%", rain);
+	int text_width = u8g2Fonts.getUTF8Width("88 %");
+
+	return DIM(w + SPACING + text_width, h);
+}
+
+static uint32_t draw_pressure(int16_t x, int16_t y, int pressure) {
+	uint16_t w = barometer_width, h = barometer_height;
+	draw_icon(x, y, barometer_bits, w, h);
+	u8g2Fonts.setCursor(x + w + SPACING, y + h/2 + FONTSIZE/2);
+	u8g2Fonts.printf("%d hPa", pressure);
+
+	return DIM(w, h);
+}
+
+static uint32_t draw_clouds(int16_t x, int16_t y, int clouds) {
+	uint16_t w = cloud_width, h = cloud_height;
+	draw_icon(x, y, cloud_bits, w, h);
+	u8g2Fonts.setCursor(x + w + SPACING, y + h/2 + FONTSIZE/2);
+	u8g2Fonts.printf("%d %%", clouds);
+	int text_width = u8g2Fonts.getUTF8Width("88 %");
+
+	return DIM(w + SPACING + text_width, h);
+}
+
+static int draw_weather_forecast(int16_t x, int16_t y, const char *title, const JsonObject &json) {
+	auto temp_min = json["temp"]["min"].as<float>();
+	auto temp_max = json["temp"]["max"].as<float>();
+	auto pop = (uint8_t) (100 * json["pop"].as<float>());
+	auto cloudiness = json["clouds"].as<int>();
+	auto description = json["weather"][0]["description"].as<char *>();
+
+	/* line 1 */
+	u8g2Fonts.setFont(u8g2_font_helvB10_tf);
+	u8g2Fonts.setCursor(x, y);
+	u8g2Fonts.print(title);
+	u8g2Fonts.setFont(u8g2_font_helvR10_tf);
+	u8g2Fonts.print("  ");
+	u8g2Fonts.print(description);
+
+	/* line 2 */
+	uint32_t dim = 0;
+	y += SPACING;
+	dim = draw_temperature(x, y, temp_min, temp_max);
+	x += GETW(dim) + SPACING;
+	dim = draw_clouds(x, y, cloudiness);
+	x += GETW(dim) + SPACING;
+	dim = draw_rain_prob(x, y, pop);
+
+	return DIM(0, FONTSIZE + GETH(dim) + 2 * SPACING);
+}
+
+void draw_weather(int16_t x0, int16_t y0) {
+	if (json_state != DeserializationError::Ok)
+		return;
+
+	/* current weather */
+	auto current_temp = weather_json["current"]["temp"].as<float>();
+	auto current_weather_id = weather_json["current"]["weather"][0]["id"].as<int>();
+	auto current_weather_desc = weather_json["current"]["weather"][0]["description"].as<char *>();
+	auto current_clouds = weather_json["current"]["clouds"].as<int>();
+	auto current_humidity = weather_json["current"]["humidity"].as<int>();
+	auto current_pressure = weather_json["current"]["pressure"].as<int>();
+
+	if (!current_weather_desc)
+		current_weather_desc = "N/A";
+
+	u8g2Fonts.setFont(u8g2_font_helvR10_tf);
+
+	uint32_t dim = 0;
+	int16_t x1 = x0, y1 = y0;
+	dim = draw_weather_icon(x0, y0, current_weather_id);
+	x1 += GETW(dim) + SPACING;
+	y1 += GETH(dim) + SPACING;
+
+	/* line 1 */
+	int16_t x = x1, y = y0 + 2 * SPACING;
+	uint32_t temp_dim = draw_temperature(x, y, current_temp);
+	x += GETW(temp_dim) + 2 * SPACING;
+	dim = draw_clouds(x, y, current_clouds);
+	y += GETH(dim);
+
+	/* line 2 */
+	x = x1;
+	dim = draw_humidity(x, y, current_humidity);
+	x += GETW(temp_dim) + 2 * SPACING;
+	dim = draw_pressure(x, y, current_pressure);
+	y += GETH(dim);
+
+	/* forecasts */
+	x = x0;
+	y = y1;
+	dim = draw_weather_forecast(x, y, "Heute:", weather_json["daily"][0]);
+	y += GETH(dim);
+	dim = draw_weather_forecast(x, y, "Morgen:", weather_json["daily"][1]);
+	y += GETH(dim);
+	dim = draw_weather_forecast(x, y, "Übermorgen:", weather_json["daily"][2]);
+	y += GETH(dim);
+}