#ifndef TIMER_PRESCALER
# if F_CPU > 16000000
# define TIMER_PRESCALER 256
-# elif F_CPU >= 4000000
+# elif F_CPU > 2000000
# define TIMER_PRESCALER 64
-# else
+# elif F_CPU > 250000
# define TIMER_PRESCALER 8
+# else
+# define TIMER_PRESCALER 1
# endif
#endif
#define TIMER_RAW_FREQ (F_CPU/TIMER_PRESCALER)
#endif
#define TIMER_DIFF(a, b, max) ((a) >= (b) ? (a) - (b) : (max) - (b) + (a))
-#define TIMER_DIFF_RAW(a, b) TIMER_DIFF(a, b, UINT8_MAX)
-#define TIMER_DIFF_MS(a, b) TIMER_DIFF(a, b, UINT16_MAX)
+#define TIMER_DIFF_8(a, b) TIMER_DIFF(a, b, UINT8_MAX)
+#define TIMER_DIFF_16(a, b) TIMER_DIFF(a, b, UINT16_MAX)
+#define TIMER_DIFF_32(a, b) TIMER_DIFF(a, b, UINT32_MAX)
+#define TIMER_DIFF_RAW(a, b) TIMER_DIFF_8(a, b)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
-extern volatile uint16_t timer_count;
+extern volatile uint32_t timer_count;
void timer_init(void);
void timer_clear(void);
uint16_t timer_read(void);
+uint32_t timer_read32(void);
uint16_t timer_elapsed(uint16_t last);
+uint32_t timer_elapsed32(uint32_t last);
+
+#ifdef __cplusplus
+}
+#endif
#endif