1 files changed, 76 insertions, 0 deletions
diff --git a/usb-i2c-sl018/ajar.c b/usb-i2c-sl018/ajar.c
new file mode 100644
index 0000000..54bd6fb
--- /dev/null
+++ b/usb-i2c-sl018/ajar.c
@@ -0,0 +1,76 @@
+/*
+ *  spreadspace avr utils
+ *
+ *
+ *  Copyright (C) 2013 Christian Pointner <equinox@spreadspace.org>
+ *                     Othmar Gsenger <otti@wirdorange.org>
+ *
+ *  This file is part of spreadspace avr utils.
+ *
+ *  spreadspace avr utils is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  any later version.
+ *
+ *  spreadspace avr utils is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with spreadspace avr utils. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <avr/io.h>
+#include <stdio.h>
+#include "ajar.h"
+
+#define AJAR_PIN PIND
+#define AJAR_PORT PORTD
+#define AJAR_DDR DDRD
+#define AJAR_BIT 4
+
+#define AJAR_LP_MAX 255
+
+void init_ajar(void)
+{
+  AJAR_DDR = AJAR_DDR & ~(1<<AJAR_BIT);
+  AJAR_PORT |= (1<<AJAR_BIT);
+}
+
+ajar_t ajar_get(void)
+{
+  static uint8_t last_state = (1<<AJAR_BIT);
+  static uint8_t lp_cnt = 0;
+
+  uint8_t state = AJAR_PIN & (1<<AJAR_BIT);
+  if(state != last_state)
+    lp_cnt++;
+  else
+    lp_cnt += lp_cnt ? -1 : 0;
+
+  if(lp_cnt >= AJAR_LP_MAX) {
+    last_state = state;
+    lp_cnt = 0;
+  }
+  
+  if(last_state) 
+    return ajar;
+  return shut;
+}
+
+const char* ajar_to_string(ajar_t a)
+{
+  return a == ajar ? "ajar" : "shut";
+}
+
+void ajar_task(void)
+{
+  static ajar_t last_state = shut;
+
+  ajar_t state = ajar_get();
+  if(last_state != state)
+    printf("Door is now: %s\n\r", ajar_to_string(state));
+  
+  last_state = state;
+}