first re-commit.

pigpio-master/EXAMPLES/C/WIEGAND_CODE/wiegand.h

@@ -0,0 +1,32 @@
+#ifndef WIEGAND_H
+#define WIEGAND_H
+
+#include <stdint.h>
+
+typedef void (*Pi_Wieg_CB_t)(int, uint32_t);
+
+struct _Pi_Wieg_s;
+
+typedef struct _Pi_Wieg_s Pi_Wieg_t;
+
+Pi_Wieg_t *Pi_Wieg(int gpio_0, int gpio_1, Pi_Wieg_CB_t callback, int timeout);
+   /*
+      This function establishes a Wiegand decoder on gpio_0 and gpio_1.
+
+      A gap of timeout milliseconds without a new bit indicates the
+      end of a code.
+
+      When the code is ended the callback function is called with the code
+      bit length and value.
+
+      A pointer to a private data type is returned.  This should be passed
+      to Pi_Wieg_cancel if the decoder is to be cancelled.
+   */
+
+void Pi_Wieg_cancel(Pi_Wieg_t *wieg);
+   /*
+      This function releases the resources used by the decoder.
+   */
+
+#endif
+