From 76edd6c448c55c4f9bcf37509ec372149c966993 Mon Sep 17 00:00:00 2001
From: schneefux <schneefux+commit@schneefux.xyz>
Date: Fri, 25 Dec 2015 13:38:31 +0100
Subject: first commit

---
 weather.cpp | 122 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 122 insertions(+)
 create mode 100644 weather.cpp

(limited to 'weather.cpp')

diff --git a/weather.cpp b/weather.cpp
new file mode 100644
index 0000000..4fabb1e
--- /dev/null
+++ b/weather.cpp
@@ -0,0 +1,122 @@
+#include "weather.h"
+
+//#define DEBUG
+
+#define HTTP_TIMEOUT 5000  // ms
+#define DOWNLOADSIZE 1100  // http buffer size, *should* be enough for a cnt=2 request
+#define JSONSIZE 1500  // json buffer size, for a cnt=2 request
+// ^ be careful with counter over/underflows!
+
+#define CITYID "YOURCITYID"
+#define APIKEY "YOURAPIKEY"
+
+#define APIHOST "api.openweathermap.org"
+#define APIPATH "/data/2.5/forecast?id=" CITYID "&appid=" APIKEY "&cnt=2"
+// "cnt=2" for 3 hour forecast
+
+// queries OWM for the 3-hour-forecast, returns icon code
+// see http://openweathermap.org/weather-conditions for codes
+String getWeatherStatus() {
+#ifdef DEBUG
+  Serial.println("Requesting weather data.");
+#endif
+
+  WiFiClient cli;
+  cli.connect(APIHOST, 80);
+  cli.println("GET " APIPATH " HTTP/1.1");
+  cli.println("Host: " APIHOST);
+  cli.println("Connection: close\r\n");
+
+#ifdef DEBUG
+  Serial.println("Sent request: " APIHOST APIPATH);
+#endif
+
+  unsigned int timeoutTimer = HTTP_TIMEOUT;
+  boolean gotHeaders = false;
+
+  // skip headers
+  while (cli.connected() && timeoutTimer-- && !gotHeaders) {
+    while (cli.available()) {
+      String line = cli.readStringUntil('\n');
+      if (line == "\r") {
+        gotHeaders = true;
+        break;
+      }
+    }
+    delay(1);
+  }
+  if (!gotHeaders) {
+#ifdef DEBUG
+    Serial.println("Did not receive headers.");
+#endif
+    cli.stop();
+    if (!cli.connected()) {
+#ifdef DEBUG
+      Serial.println("Connection was reset.");
+#endif
+    }
+    return "-1";
+  }
+
+  // read response into char array
+  char response[DOWNLOADSIZE];
+  unsigned int buffPointer = 0;
+  boolean jsonStarted = false;
+  int charsSinceJsonEnd = 0;
+  while (cli.connected() && timeoutTimer-- && buffPointer < DOWNLOADSIZE) {
+    while (cli.available() && buffPointer < DOWNLOADSIZE) {
+      char ch = (char) cli.read();
+      if (!jsonStarted) {
+        if (ch == '{') {
+          jsonStarted = true;
+        }
+      }
+      if (jsonStarted) {
+        if (ch == '}') {
+          charsSinceJsonEnd = 0;
+        } else {
+          charsSinceJsonEnd++;
+        }
+        response[buffPointer++] = ch;
+      }
+    }
+    delay(1);
+  }
+  cli.stop();
+  response[buffPointer - charsSinceJsonEnd] = '\0';  // OWM seems to send some weird extra characters we do not want
+
+  if (!timeoutTimer) {
+#ifdef DEBUG
+    Serial.println("Timed out.");
+#endif
+    return "-1";
+  }
+  if (buffPointer == DOWNLOADSIZE) {
+#ifdef DEBUG
+    Serial.println("Maximum buffer size exceeded.");
+#endif
+    return "-1";
+  }
+
+#ifdef DEBUG
+  Serial.println("'" + String(response) + "'");
+#endif
+
+  StaticJsonBuffer<JSONSIZE> json;
+  JsonObject& root = json.parseObject(response);
+  if (!root.success()) {
+#ifdef DEBUG
+    Serial.println("JSON invalid.");
+#endif
+    return "-1";
+  }
+  String strConditionId = root["list"][1]["weather"][0]["icon"].asString();
+  if (!strConditionId.length()) {
+    return "-1";
+  }
+#ifdef DEBUG
+  Serial.println("Parsed JSON. Weather code: " + strConditionId);
+#endif
+  return strConditionId;  // 3 hour future weather by icon code
+}
+
-- 
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