diff options
| author | robert-hh <robert@hammelrath.com> | 2021-12-30 12:08:16 +0100 |
|---|---|---|
| committer | Damien George <damien@micropython.org> | 2022-01-06 13:51:19 +1100 |
| commit | 9e56e630caeec9077cd95ac33b702a7b2187300e (patch) | |
| tree | 22fcf2e290e025fdd90692032b10108c4fb1ebb7 | |
| parent | f4487a00494563c1c59ab1a2bef53c1c220718eb (diff) | |
rp2/machine_pwm: Fix PWM frequency setting.
The top value was off by 1: in order to count n ticks it has to be set to
n-1.
Fixes issue #8122.
| -rw-r--r-- | ports/rp2/machine_pwm.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/ports/rp2/machine_pwm.c b/ports/rp2/machine_pwm.c index 2952a4306..d2cb93795 100644 --- a/ports/rp2/machine_pwm.c +++ b/ports/rp2/machine_pwm.c @@ -91,7 +91,7 @@ STATIC mp_obj_t mp_machine_pwm_freq_get(machine_pwm_obj_t *self) { uint32_t source_hz = clock_get_hz(clk_sys); uint32_t div16 = pwm_hw->slice[self->slice].div; uint32_t top = pwm_hw->slice[self->slice].top; - uint32_t pwm_freq = 16 * source_hz / div16 / top; + uint32_t pwm_freq = 16 * source_hz / div16 / (top + 1); return MP_OBJ_NEW_SMALL_INT(pwm_freq); } @@ -123,7 +123,7 @@ STATIC void mp_machine_pwm_freq_set(machine_pwm_obj_t *self, mp_int_t freq) { mp_raise_ValueError(MP_ERROR_TEXT("freq too small")); } pwm_hw->slice[self->slice].div = div16_top; - pwm_hw->slice[self->slice].top = top; + pwm_hw->slice[self->slice].top = top - 1; } STATIC mp_obj_t mp_machine_pwm_duty_get_u16(machine_pwm_obj_t *self) { |