diff options
| -rw-r--r-- | extmod/utime_mphal.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/extmod/utime_mphal.c b/extmod/utime_mphal.c index 1a32180cf5..9aa2f13245 100644 --- a/extmod/utime_mphal.c +++ b/extmod/utime_mphal.c @@ -89,7 +89,13 @@ STATIC mp_obj_t time_ticks_diff(mp_obj_t end_in, mp_obj_t start_in) { // we assume that the arguments come from ticks_xx so are small ints uint32_t start = MP_OBJ_SMALL_INT_VALUE(start_in); uint32_t end = MP_OBJ_SMALL_INT_VALUE(end_in); - return MP_OBJ_NEW_SMALL_INT((int32_t)(end - start)); + int32_t diff = end - start; + if (diff < (signed)-(MICROPY_PY_UTIME_TICKS_PERIOD / 2)) { + diff += MICROPY_PY_UTIME_TICKS_PERIOD; + } else if (diff >= (signed)(MICROPY_PY_UTIME_TICKS_PERIOD / 2)) { + diff -= MICROPY_PY_UTIME_TICKS_PERIOD; + } + return MP_OBJ_NEW_SMALL_INT(diff); } MP_DEFINE_CONST_FUN_OBJ_2(mp_utime_ticks_diff_obj, time_ticks_diff); |