-/// util.h
-#define LED_RED 1
-#define LED_ORANGE 2
-#define LED_GREEN 4
-#define LED_RED2 8
-#define BUTTON_HOLD 1
-#define BUTTON_NO_CLICK 0
-#define BUTTON_SINGLE_CLICK -1
-#define BUTTON_DOUBLE_CLICK -2
-#define BUTTON_ERROR -99
-int strlen(char *str);
-void *memcpy(void *dest, const void *src, int len);
-void *memset(void *dest, int c, int len);
-int memcmp(const void *av, const void *bv, int len);
-char *strncat(char *dest, const char *src, unsigned int n);
-void num_to_bytes(uint64_t n, size_t len, byte_t* dest);
-uint64_t bytes_to_num(byte_t* src, size_t len);