first re-commit.

pigpio-master/EXAMPLES/C/ROTARY_ENCODER/rotary_encoder.h

@@ -0,0 +1,25 @@
+#ifndef ROTARY_ENCODER_H
+#define ROTARY_ENCODER_H
+
+typedef void (*Pi_Renc_CB_t)(int);
+
+struct _Pi_Renc_s;
+
+typedef struct _Pi_Renc_s Pi_Renc_t;
+
+Pi_Renc_t * Pi_Renc(int gpioA, int gpioB, Pi_Renc_CB_t callback);
+/*
+   This function establishes a rotary encoder on gpioA and gpioB.
+
+   When the encoder is turned the callback function is called.
+
+   A pointer to a private data type is returned.  This should be passed
+   to Pi_Renc_cancel if the rotary encoder is to be cancelled.
+*/
+
+void Pi_Renc_cancel(Pi_Renc_t *renc);
+/*
+   This function releases the resources used by the decoder.
+*/
+
+#endif