// Helper function for determining the period used for calculating percent
STATIC uint32_t compute_period(pyb_timer_obj_t *self) {
// In center mode, compare == period corresponds to 100%
// In edge mode, compare == (period + 1) corresponds to 100%
uint32_t period = (__HAL_TIM_GetAutoreload(&self->tim) & TIMER_CNT_MASK(self));
if (period != 0xffffffff) {
if (self->tim.Init.CounterMode == TIM_COUNTERMODE_UP ||
self->tim.Init.CounterMode == TIM_COUNTERMODE_DOWN) {
// Edge mode
period++;
}
}
return period;
}
STATIC void pyb_timer_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
pyb_timer_obj_t *self = self_in;
if (self->tim.State == HAL_TIM_STATE_RESET) {
print(env, "Timer(%u)", self->tim_id);
} else {
print(env, "Timer(%u, prescaler=%u, period=%u, mode=%s, div=%u)",
self->tim_id,
self->tim.Instance->PSC & 0xffff,
__HAL_TIM_GetAutoreload(&self->tim) & TIMER_CNT_MASK(self),
self->tim.Init.CounterMode == TIM_COUNTERMODE_UP ? "UP" :
self->tim.Init.CounterMode == TIM_COUNTERMODE_DOWN ? "DOWN" : "CENTER",
self->tim.Init.ClockDivision == TIM_CLOCKDIVISION_DIV4 ? 4 :
self->tim.Init.ClockDivision == TIM_CLOCKDIVISION_DIV2 ? 2 : 1);
}
}
STATIC mp_obj_t pyb_timer_init_helper(pyb_timer_obj_t *self, mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
// parse args
mp_arg_val_t vals[PYB_TIMER_INIT_NUM_ARGS];
mp_arg_parse_all(n_args, args, kw_args, PYB_TIMER_INIT_NUM_ARGS, pyb_timer_init_args, vals);
// set the TIM configuration values
TIM_Base_InitTypeDef *init = &self->tim.Init;
if (vals[0].u_int != 0xffffffff) {
// set prescaler and period from frequency
if (vals[0].u_int == 0) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "can't have 0 frequency"));
}
// work out TIM's clock source
uint tim_clock;
if (self->tim_id == 1 || (8 <= self->tim_id && self->tim_id <= 11)) {
// TIM{1,8,9,10,11} are on APB2
tim_clock = HAL_RCC_GetPCLK2Freq();
} else {
// TIM{2,3,4,5,6,7,12,13,14} are on APB1
tim_clock = HAL_RCC_GetPCLK1Freq();
}
// Compute the prescaler value so TIM triggers at freq-Hz
// On STM32F405/407/415/417 there are 2 cases for how the clock freq is set.
// If the APB prescaler is 1, then the timer clock is equal to its respective
// APB clock. Otherwise (APB prescaler > 1) the timer clock is twice its
// respective APB clock. See DM00031020 Rev 4, page 115.
uint32_t period = MAX(1, 2 * tim_clock / vals[0].u_int);
uint32_t prescaler = 1;
while (period > TIMER_CNT_MASK(self)) {
period >>= 1;
prescaler <<= 1;
}
init->Prescaler = prescaler - 1;
init->Period = period - 1;
} else if (vals[1].u_int != 0xffffffff && vals[2].u_int != 0xffffffff) {
