humidity: wip

6 files changed, 136 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index f0609a0..b494daa 100644
--- a/Makefile
+++ b/Makefile
@@ -1,11 +1,14 @@
 CFLAGS=-Werror -O3 -pedantic
 
-anzeige: anzeige.c fonts.o input_gadgets.o multiplexer.o
+anzeige: anzeige.c fonts.o humidity.o input_gadgets.o multiplexer.o
 	gcc -o "$@" $(CFLAGS) -lpthread -lzip -lxml2 -lcurl $^
 
 fonts.o: fonts.c fonts.h
 	gcc -o "$@" $(CFLAGS) -c "$<"
 
+humidity.o: humidity.c humidity.h
+	gcc -o "$@" $(CFLAGS) -c "$<"
+
 input_gadgets.o: input_gadgets.c input_gadgets.h
 	gcc -o "$@" $(CFLAGS) -c -I/usr/include/libxml2 -lzip -lxml2 -lcurl "$<"
 
diff --git a/anzeige.c b/anzeige.c
index 67a2046..311b4ac 100644
--- a/anzeige.c
+++ b/anzeige.c
@@ -112,6 +112,17 @@ int main(int argc, char **argv)
         turn_off_display();
         return EXIT_FAILURE;
       }
+      if (text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end > 0)
+        text_buffer_end += snprintf(text_buffer_end, text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end, "; ");
+      text_buffer_end = gadgets_retrieve_humidity(text_buffer_end, text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end, temperature, humidity);
+      if (text_buffer_end == NULL) {
+        fprintf(stderr, "gadgets_retrieve_humidity failed\n");
+        free(text_buffer);
+        turn_off_display();
+        return EXIT_FAILURE;
+      }
+      printf("%s\n", text_buffer);
+      return 0;
       struct tm time_struct;
       memset(&time_struct, 0, sizeof(time_struct));
       localtime_r(&next_update, &time_struct);
diff --git a/humidity.c b/humidity.c
new file mode 100644
index 0000000..527492b
--- /dev/null
+++ b/humidity.c
@@ -0,0 +1,17 @@
+#include "humidity.h"
+
+double maximale_luftfeuchte(double t)
+{
+  for (int i=1; i<DAMPF_ANZ; i++)
+    if (dampf_temperaturen[i]>=t)
+      return (t-dampf_temperaturen[i-1])*(dampf_feuchten[i]-dampf_feuchten[i-1])/(dampf_temperaturen[i]-dampf_temperaturen[i-1]);
+  return -1;
+}
+
+double taupunkt(double af)
+{
+  for (int i=1; i<DAMPF_ANZ; i++)
+    if (dampf_feuchten[i]>=af)
+      return (af-dampf_feuchten[i-1])*(dampf_temperaturen[i]-dampf_temperaturen[i-1])/(dampf_feuchten[i]-dampf_feuchten[i-1]);
+  return -1;
+}
diff --git a/humidity.h b/humidity.h
new file mode 100644
index 0000000..2e8b155
--- /dev/null
+++ b/humidity.h
@@ -0,0 +1,30 @@
+#ifndef HUMIDITY_H
+#define HUMIDITY_H
+
+#define DAMPF_ANZ  69
+
+double dampf_temperaturen[DAMPF_ANZ] = {
+  -100, -95, -90, -85, -80, -75, -70, -65, -60, -55, -50, -45, -40, -35,
+  -30, -25, -20, -15, -10, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7,
+  8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
+  26, 27, 28, 29, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90,
+  95, 100
+};
+
+double dampf_feuchten[DAMPF_ANZ] = {
+  1.7465E-5, 4.5752E-5, 1.1373E-4, 2.6939E-4, 6.1013E-4, 1.3260E-3,
+  2.7735E-3, 0.005598, 0.010930, 0.020692, 0.038056, 0.068124, 0.11890,
+  0.20265, 0.33776, 0.55127, 0.88211, 1.3854, 2.1380, 3.2449, 3.5205,
+  3.8172, 4.1363, 4.4794, 4.84795, 5.19317, 5.55921, 5.94766, 6.35967,
+  6.79642, 7.25917, 7.74919, 8.26783, 8.81648, 9.39658, 10.0096,
+  10.6572, 11.3408, 12.0623, 12.8232, 13.6254, 14.4707, 15.3611,
+  16.2984, 17.2848, 18.3224, 19.4132, 20.5596, 21.7638, 23.0283,
+  24.3554, 25.7477, 27.2079, 28.7385, 30.3424, 39.5623, 51.0726,
+  65.3114, 82.7730, 104.011, 129.642, 160.344, 196.863, 240.011,
+  290.669, 349.782, 418.369, 497.511, 588.359
+};
+
+double maximale_luftfeuchte(double t);
+double taupunkt(double af);
+
+#endif // HUMIDITY_H
diff --git a/input_gadgets.c b/input_gadgets.c
index 16a263d..40d22b1 100644
--- a/input_gadgets.c
+++ b/input_gadgets.c
@@ -11,10 +11,12 @@
 #include <zip.h>
 
 #include "input_gadgets.h"
+#include "humidity.h"
 
 #define fh_temperature_regex   "\n\\s*Wetterdaten vom ([0-9]{2}\\.[0-9]{2}\\.[0-9]{4} um [0-9]{2}:[0-9]{2} MEZ)</strong>(.|\n)*>Temperatur</td>\\s*\n\\s*<td [^>]*><strong>([^<]*)</strong>(.|\n)*>Luftfeuchtigkeit</td>\\s*\n\\s*<td [^>]*><strong>([^<]*)</strong>"
 #define wetter_warnung_filename_regex "^2\\.49\\.0\\.1\\.276\\.0\\.DWD\\.PVW\\.([0-9]+)\\."
 #define warnings_future_timespan  (60*60*10)
+#define kpi_regex   "RH: (-?[0-9.]+) %\nT: (-?[0-9.]+) "
 
 static size_t
 WriteMemoryCallback(void *contents, size_t size, size_t nmemb, void *userp)
@@ -969,3 +971,74 @@ char *gadgets_retrieve_weather_warnings(char *output, int max_len)
 
   return ende;
 }
+
+char *gadgets_retrieve_humidity(char *output, int max_len, double fh_temperature, double fh_humidity)
+{
+  CURL *curl_handle;
+  CURLcode res;
+  MemoryStruct chunk;
+  int ret_val;
+  double temperature, humidity;
+
+  chunk.memory = malloc(1);
+  chunk.size = 0;
+
+  curl_global_init(CURL_GLOBAL_ALL);
+
+  curl_handle = curl_easy_init();
+  if (!curl_handle) {
+    perror("Failed to init curl");
+    free(chunk.memory);
+    return NULL;
+  }
+  curl_easy_setopt(curl_handle, CURLOPT_URL, "https://kpi.ddns.eckner.net/tmp/sensor");
+  curl_easy_setopt(curl_handle, CURLOPT_FOLLOWLOCATION, 1L);
+  curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
+  curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void *)&chunk);
+  curl_easy_setopt(curl_handle, CURLOPT_USERAGENT, "libcurl-agent/1.0");
+  res = curl_easy_perform(curl_handle);
+  curl_easy_cleanup(curl_handle);
+  if (res != CURLE_OK) {
+    fprintf(
+      stderr,
+      "curl_easy_perform(%s) failed: %s\n",
+      "https://kpi.ddns.eckner.net/tmp/sensor",
+      curl_easy_strerror(res)
+    );
+    free(chunk.memory);
+    if (res != CURLE_COULDNT_RESOLVE_HOST && res != CURLE_COULDNT_CONNECT)
+      return NULL;
+    char *ende = output;
+    if (max_len > 0)
+      ende += snprintf(ende, max_len, "%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c", 0xEE, 0x01, 0xEE, 0x02, 0xEE, 0x01, 0xEE, 0x02, 0xEE, 0x05, 0xEE, 0x06, 0xEE, 0x05, 0xEE, 0x06);
+    return ende;
+  }
+
+  regex_t re;
+  regmatch_t rm[3];
+  if (regcomp(&re, kpi_regex, REG_EXTENDED|REG_NEWLINE) != 0) {
+    fprintf(stderr, "Failed to compile regex '%s'\n", kpi_regex);
+    free(chunk.memory);
+    return NULL;
+  }
+  if (ret_val = regexec(&re, chunk.memory, 3, rm, 0)) {
+    char *reg_err;
+    reg_err = malloc(1024);
+    regerror(ret_val, &re, reg_err, 1024);
+    fprintf(stderr, "%d %s\n",ret_val,reg_err);
+    regfree(&re);
+    free(chunk.memory);
+    return NULL;
+  }
+  regfree(&re);
+
+  char tmp_str[12];
+  sprintf(tmp_str, "%.*s", (int)(rm[1].rm_eo - rm[1].rm_so), (char*)(chunk.memory + rm[1].rm_so));
+  humidity = atof(tmp_str);
+  sprintf(tmp_str, "%.*s", (int)(rm[2].rm_eo - rm[2].rm_so), (char*)(chunk.memory + rm[2].rm_so));
+  temperature = atof(tmp_str);
+
+  output += snprintf(output, max_len, "%f -> %f; %f -> %f", fh_temperature, temperature, fh_humidity, humidity);
+  free(chunk.memory);
+  return output;
+}
diff --git a/input_gadgets.h b/input_gadgets.h
index eee6915..b3e3644 100644
--- a/input_gadgets.h
+++ b/input_gadgets.h
@@ -18,5 +18,6 @@ typedef struct {
 char *gadgets_retrieve_current_temperature(char *output, int max_len, double *temperature, double *humidity);
 char *gadgets_retrieve_weather_forecast(char *output, int max_len);
 char *gadgets_retrieve_weather_warnings(char *output, int max_len);
+char *gadgets_retrieve_humidity(char *output, int max_len, double fh_temperature, double fh_humidity);
 
 #endif // INPUT_GADGETS_H