添加一些关于midi播放的项目

Midi/music-box-nv32-master/KeyScan.h

@@ -0,0 +1,28 @@
+#ifndef __KEY_SCAN_H__
+#define __KEY_SCAN_H__
+#include <stdint.h>
+
+#define KEY_ACTIVE 0
+#define SCAN_INTERVAL_MS 20
+
+enum KEY_INDEX
+{
+    USER_KEY_1 = 0,
+    USER_KEY_2,
+    KEY_NUM
+};
+
+enum KEY_STATUS
+{
+    KEY_STATUS_IDLE = 0,
+    KEY_STATUS_PRESSED,
+    KEY_STATUS_RELEASED,
+};
+
+void KeyRawInput(uint32_t keyIndex, uint32_t keyValue);
+void KeyDefaultCallBack(uint32_t param);
+void KeySetCallBack(uint32_t keyIndex, void (*cb)(uint32_t));
+void KeyProcess(uint32_t currentMills);
+void KeyScanInit(void);
+
+#endif