split of logical parts into separate files

7 files changed, 258 insertions, 167 deletions

diff --git a/.gitignore b/.gitignore
index ff41870..7b72871 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 anzeige
+*.o
diff --git a/Makefile b/Makefile
index d2f3cb0..9ac123a 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,13 @@
-anzeige: anzeige.c fonts.h
-	gcc -o "$@" -Werror=implicit-function-declaration -lpthread "$<"
+CFLAGS="-Werror=implicit-function-declaration"
+
+anzeige: anzeige.c fonts.h input_gadgets.o multiplexer.o
+	gcc -o "$@" $(CFLAGS) -lpthread -lcurl $^
+
+input_gadgeds.o: input_gadgeds.c input_gadgeds.h
+	gcc -o "$@" $(CFLAGS) -c -lcurl "$<"
+
+multiplexer.o: multiplexer.c multiplexer.h
+	gcc -o "$@" $(CFLAGS) -c -lpthread "$<"
 
 all: anzeige
 
diff --git a/anzeige.c b/anzeige.c
index b08d4d6..0e6713c 100644
--- a/anzeige.c
+++ b/anzeige.c
@@ -1,18 +1,3 @@
-//
-//  How to access GPIO registers from C-code on the Raspberry-Pi
-//  Example program
-//  15-January-2012
-//  Dom and Gert
-//  Revised: 15-Feb-2013
-
-#ifndef __arm__
-#define SKIP_GPIO
-#endif
-
-// Access from ARM Running Linux
-
-#define BCM2708_PERI_BASE        0x20000000
-#define GPIO_BASE                (BCM2708_PERI_BASE + 0x200000) /* GPIO controller */
 #define _GNU_SOURCE
 
 #include <stdio.h>
@@ -25,67 +10,25 @@
 #include <pthread.h>
 
 #include "fonts.h"
+#include "input_gadgets.h"
+#include "multiplexer.h"
 
-#define PAGE_SIZE (4*1024)
-#define BLOCK_SIZE (4*1024)
-
-#define SER_DAT_PIN   26
-#define SER_CLK_PIN   19
-#define GATE_PIN      13
-#define PAR_CLK_PIN    6
-#define SENSE_PIN      5
-
-int  mem_fd;
-void *gpio_map;
-
-typedef struct {
-   char buf[3][40];
-   int should_buf, is_buf, keep_running;
-} t_display_data;
-
-// I/O access
-volatile unsigned *gpio;
-
-
-// GPIO setup macros. Always use INP_GPIO(x) before using OUT_GPIO(x) or SET_GPIO_ALT(x,y)
-#define INP_GPIO(g) *(gpio+((g)/10)) &= ~(7<<(((g)%10)*3))
-#define OUT_GPIO(g) *(gpio+((g)/10)) |=  (1<<(((g)%10)*3))
-#define SET_GPIO_ALT(g,a) *(gpio+(((g)/10))) |= (((a)<=3?(a)+4:(a)==4?3:2)<<(((g)%10)*3))
-
-#define GPIO_SET *(gpio+7)  // sets   bits which are 1 ignores bits which are 0
-#define GPIO_CLR *(gpio+10) // clears bits which are 1 ignores bits which are 0
-#define GPIO_ALTER(a) *(gpio+(a==0?10:7))  // alters (a==0: clear, else: set)  bits which are 1 ignores bits which are 0
-
-#define GET_GPIO(g) (*(gpio+13)&(1<<g)) // 0 if LOW, (1<<g) if HIGH
-
-#define GPIO_PULL *(gpio+37) // Pull up/pull down
-#define GPIO_PULLCLK0 *(gpio+38) // Pull up/pull down clock
-
-void setup_io();
 void drop_privileges();
-void *put_on_display(void *param);
-
-void printButton(int g)
-{
-  if (GET_GPIO(g)) // !=0 <-> bit is 1 <- port is HIGH=3.3V
-    printf("Button pressed!\n");
-  else // port is LOW=0V
-    printf("Button released!\n");
-}
 
 int main(int argc, char **argv)
 {
   pthread_t thread_id;
   t_display_data display_data;
 
-#ifndef SKIP_GPIO
   // Set up gpi pointer for direct register access
-  setup_io();
-#endif
+  multiplexer_setup_root();
 
   // Drop root privileges
   drop_privileges();
 
+  gadgets_retrieve_temperature();
+  return 0;
+
  /************************************************************************\
   * You are about to change the GPIO settings of your computer.          *
   * Mess this up and it will stop working!                               *
@@ -93,25 +36,8 @@ int main(int argc, char **argv)
   * so at least you still have your code changes written to the SD-card! *
  \************************************************************************/
 
-#ifndef SKIP_GPIO
-  // must use INP_GPIO before we can use OUT_GPIO
-  INP_GPIO(SER_DAT_PIN);
-  OUT_GPIO(SER_DAT_PIN);
-  INP_GPIO(SER_CLK_PIN);
-  OUT_GPIO(SER_CLK_PIN);
-  INP_GPIO(GATE_PIN);
-  OUT_GPIO(GATE_PIN);
-  INP_GPIO(PAR_CLK_PIN);
-  OUT_GPIO(PAR_CLK_PIN);
-  INP_GPIO(SENSE_PIN);
-#endif
-
-  for (int i=0; i<3; i++)
-    memset(display_data.buf[i],0,40);
-  display_data.is_buf = 0;
-  display_data.should_buf = 0;
-  display_data.keep_running = 1;
-  pthread_create(&thread_id, NULL, put_on_display, &display_data);
+  // configure the gpio pins and start the multiplexer thread
+  thread_id = multiplexer_setup_non_root(&display_data);
 
   for (int i=0; i<20; i++) {
     usleep(2500000);
@@ -127,41 +53,6 @@ int main(int argc, char **argv)
 
 } // main
 
-
-//
-// Set up a memory regions to access GPIO
-//
-void setup_io()
-{
-   /* open /dev/mem */
-   if ((mem_fd = open("/dev/mem", O_RDWR|O_SYNC) ) < 0) {
-      perror("can't open /dev/mem");
-      exit(-1);
-   }
-
-   /* mmap GPIO */
-   gpio_map = mmap(
-      NULL,             //Any adddress in our space will do
-      BLOCK_SIZE,       //Map length
-      PROT_READ|PROT_WRITE,// Enable reading & writting to mapped memory
-      MAP_SHARED,       //Shared with other processes
-      mem_fd,           //File to map
-      GPIO_BASE         //Offset to GPIO peripheral
-   );
-
-   close(mem_fd); //No need to keep mem_fd open after mmap
-
-   if (gpio_map == MAP_FAILED) {
-      perror("mmap error");
-      exit(-1);
-   }
-
-   // Always use volatile pointer!
-   gpio = (volatile unsigned *)gpio_map;
-
-
-} // setup_io
-
 //
 // Drop (root) privileges
 //
@@ -178,51 +69,3 @@ void drop_privileges()
       exit(-1);
    }
 } // drop_root
-
-//
-// Shift the bits provided in content into the display
-//
-void *put_on_display(void *param)
-{
-   t_display_data *display_data = param;
-   int line, column;
-
-   while (display_data -> keep_running) {
-
-#ifdef SKIP_GPIO
-      usleep(100000);
-      printf("=\n");
-#endif
-      display_data -> is_buf = display_data -> should_buf;
-      for (line=0; line<7; line++) {
-#ifdef SKIP_GPIO
-         for (column=0; column<40; column++) {
-            if ((*(display_data -> buf[display_data -> is_buf] + column)>>line) & 0x01)
-               printf("X");
-            else
-               printf(".");
-#else
-         GPIO_CLR = 1<<GATE_PIN; // Licht an
-         for (column=0; column<8; column++) {
-            GPIO_CLR = 1<<SER_CLK_PIN;
-            GPIO_ALTER(column == line) = 1<<SER_DAT_PIN;
-            GPIO_SET = 1<<SER_CLK_PIN;
-         }
-         for (column=39; column>=0; column--) {
-            GPIO_CLR = 1<<SER_CLK_PIN;
-            GPIO_ALTER((*(display_data -> buf[display_data -> is_buf] + column)>>line) & 0x01) = 1<<SER_DAT_PIN;
-            GPIO_SET = 1<<SER_CLK_PIN;
-#endif
-         }
-         usleep(1000);
-#ifdef SKIP_GPIO
-         printf("\n");
-#else
-         GPIO_SET = 1<<GATE_PIN; // Licht aus
-         GPIO_CLR = 1<<PAR_CLK_PIN;
-         GPIO_SET = 1<<PAR_CLK_PIN;
-#endif
-      }
-   }
-   return NULL;
-} // put_on_screen
diff --git a/input_gadgets.c b/input_gadgets.c
new file mode 100644
index 0000000..35dc766
--- /dev/null
+++ b/input_gadgets.c
@@ -0,0 +1,57 @@
+#include <string.h>
+#include <stdlib.h>
+#include <curl/curl.h>
+
+struct MemoryStruct {
+  char *memory;
+  size_t size;
+};
+
+static size_t
+WriteMemoryCallback(void *contents, size_t size, size_t nmemb, void *userp)
+{
+  size_t realsize = size * nmemb;
+  struct MemoryStruct *mem = (struct MemoryStruct *)userp;
+ 
+  char *ptr = realloc(mem->memory, mem->size + realsize + 1);
+  if(ptr == NULL) {
+    /* out of memory! */ 
+    printf("not enough memory (realloc returned NULL)\n");
+    return 0;
+  }
+ 
+  mem->memory = ptr;
+  memcpy(&(mem->memory[mem->size]), contents, realsize);
+  mem->size += realsize;
+  mem->memory[mem->size] = 0;
+ 
+  return realsize;
+}
+
+int gadgets_retrieve_temperature() {
+  CURL *curl_handle;
+  CURLcode res;
+  struct MemoryStruct chunk;
+
+  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");
+    return -1;
+  }
+  curl_easy_setopt(curl_handle, CURLOPT_URL, "https://wetter.mb.fh-jena.de/station/datenbank/php_giese/online.php");
+  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);
+  if (res != CURLE_OK)
+    fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
+  curl_easy_cleanup(curl_handle);
+  printf("%lu bytes retrieved\n", (unsigned long)chunk.size);
+  return 0;
+}
diff --git a/input_gadgets.h b/input_gadgets.h
new file mode 100644
index 0000000..11413a8
--- /dev/null
+++ b/input_gadgets.h
@@ -0,0 +1,2 @@
+
+void gadgets_retrieve_temperature();
diff --git a/multiplexer.c b/multiplexer.c
new file mode 100644
index 0000000..5f82ee5
--- /dev/null
+++ b/multiplexer.c
@@ -0,0 +1,128 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <pthread.h>
+
+#include "multiplexer.h"
+
+/** TODO
+void printButton(int g)
+{
+  if (GET_GPIO(g)) // !=0 <-> bit is 1 <- port is HIGH=3.3V
+    printf("Button pressed!\n");
+  else // port is LOW=0V
+    printf("Button released!\n");
+} **/
+
+
+//
+// Set up a memory regions to access GPIO
+//
+void multiplexer_setup_root()
+{
+#ifndef SKIP_GPIO
+  /* open /dev/mem */
+  if ((mem_fd = open("/dev/mem", O_RDWR|O_SYNC) ) < 0) {
+    perror("can't open /dev/mem");
+    exit(-1);
+  }
+
+  /* mmap GPIO */
+  gpio_map = mmap(
+    NULL,             //Any adddress in our space will do
+    BLOCK_SIZE,       //Map length
+    PROT_READ|PROT_WRITE,// Enable reading & writting to mapped memory
+    MAP_SHARED,       //Shared with other processes
+    mem_fd,           //File to map
+    GPIO_BASE         //Offset to GPIO peripheral
+  );
+
+  close(mem_fd); //No need to keep mem_fd open after mmap
+
+  if (gpio_map == MAP_FAILED) {
+    perror("mmap error");
+    exit(-1);
+  }
+
+  // Always use volatile pointer!
+  gpio = (volatile unsigned *)gpio_map;
+#endif
+} // multiplexer_setup_root
+
+//
+// Shift the bits provided in content into the display
+//
+void *put_on_display(void *param)
+{
+  t_display_data *display_data = param;
+  int line, column;
+
+  while (display_data -> keep_running) {
+
+#ifdef SKIP_GPIO
+    usleep(100000);
+    printf("=\n");
+#endif
+    display_data -> is_buf = display_data -> should_buf;
+    for (line=0; line<7; line++) {
+#ifdef SKIP_GPIO
+      for (column=0; column<40; column++) {
+        if ((*(display_data -> buf[display_data -> is_buf] + column)>>line) & 0x01)
+          printf("X");
+        else
+          printf(".");
+#else
+      GPIO_CLR = 1<<GATE_PIN; // Licht an
+      for (column=0; column<8; column++) {
+        GPIO_CLR = 1<<SER_CLK_PIN;
+        GPIO_ALTER(column == line) = 1<<SER_DAT_PIN;
+        GPIO_SET = 1<<SER_CLK_PIN;
+      }
+      for (column=39; column>=0; column--) {
+        GPIO_CLR = 1<<SER_CLK_PIN;
+        GPIO_ALTER((*(display_data -> buf[display_data -> is_buf] + column)>>line) & 0x01) = 1<<SER_DAT_PIN;
+        GPIO_SET = 1<<SER_CLK_PIN;
+#endif
+      }
+      usleep(1000);
+#ifdef SKIP_GPIO
+      printf("\n");
+#else
+      GPIO_SET = 1<<GATE_PIN; // Licht aus
+      GPIO_CLR = 1<<PAR_CLK_PIN;
+      GPIO_SET = 1<<PAR_CLK_PIN;
+#endif
+    }
+  }
+  return NULL;
+} // put_on_display
+
+pthread_t multiplexer_setup_non_root(t_display_data *display_data)
+{
+  pthread_t thread_id;
+
+#ifndef SKIP_GPIO
+  // must use INP_GPIO before we can use OUT_GPIO
+  INP_GPIO(SER_DAT_PIN);
+  OUT_GPIO(SER_DAT_PIN);
+  INP_GPIO(SER_CLK_PIN);
+  OUT_GPIO(SER_CLK_PIN);
+  INP_GPIO(GATE_PIN);
+  OUT_GPIO(GATE_PIN);
+  INP_GPIO(PAR_CLK_PIN);
+  OUT_GPIO(PAR_CLK_PIN);
+  INP_GPIO(SENSE_PIN);
+#endif
+
+  for (int i=0; i<3; i++)
+    memset(display_data -> buf[i],0,40);
+  display_data -> is_buf = 0;
+  display_data -> should_buf = 0;
+  display_data -> keep_running = 1;
+  pthread_create(&thread_id, NULL, put_on_display, display_data);
+  return thread_id;
+} // multiplexer_setup_non_root
diff --git a/multiplexer.h b/multiplexer.h
new file mode 100644
index 0000000..806ef19
--- /dev/null
+++ b/multiplexer.h
@@ -0,0 +1,52 @@
+//
+//  How to access GPIO registers from C-code on the Raspberry-Pi
+//  Example program
+//  15-January-2012
+//  Dom and Gert
+//  Revised: 15-Feb-2013
+
+#ifndef __arm__
+#define SKIP_GPIO
+#endif
+
+// Access from ARM Running Linux
+
+#define BCM2708_PERI_BASE        0x20000000
+#define GPIO_BASE                (BCM2708_PERI_BASE + 0x200000) /* GPIO controller */
+
+#define PAGE_SIZE (4*1024)
+#define BLOCK_SIZE (4*1024)
+
+#define SER_DAT_PIN   26
+#define SER_CLK_PIN   19
+#define GATE_PIN      13
+#define PAR_CLK_PIN    6
+#define SENSE_PIN      5
+
+int  mem_fd;
+void *gpio_map;
+
+typedef struct {
+   char buf[3][40];
+   int should_buf, is_buf, keep_running;
+} t_display_data;
+
+// I/O access
+volatile unsigned *gpio;
+
+// GPIO setup macros. Always use INP_GPIO(x) before using OUT_GPIO(x) or SET_GPIO_ALT(x,y)
+#define INP_GPIO(g) *(gpio+((g)/10)) &= ~(7<<(((g)%10)*3))
+#define OUT_GPIO(g) *(gpio+((g)/10)) |=  (1<<(((g)%10)*3))
+#define SET_GPIO_ALT(g,a) *(gpio+(((g)/10))) |= (((a)<=3?(a)+4:(a)==4?3:2)<<(((g)%10)*3))
+
+#define GPIO_SET *(gpio+7)  // sets   bits which are 1 ignores bits which are 0
+#define GPIO_CLR *(gpio+10) // clears bits which are 1 ignores bits which are 0
+#define GPIO_ALTER(a) *(gpio+(a==0?10:7))  // alters (a==0: clear, else: set)  bits which are 1 ignores bits which are 0
+
+#define GET_GPIO(g) (*(gpio+13)&(1<<g)) // 0 if LOW, (1<<g) if HIGH
+
+#define GPIO_PULL *(gpio+37) // Pull up/pull down
+#define GPIO_PULLCLK0 *(gpio+38) // Pull up/pull down clock
+
+void multiplexer_setup_root();
+pthread_t multiplexer_setup_non_root(t_display_data *display_data);