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update init_timer & frequency calculation
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microdev1 committed Nov 18, 2020
1 parent ff987e7 commit c457d37
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Showing 2 changed files with 38 additions and 22 deletions.
55 changes: 35 additions & 20 deletions ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
Original file line number Diff line number Diff line change
Expand Up @@ -29,7 +29,7 @@
#include "py/runtime.h"

static void IRAM_ATTR pcnt_overflow_handler(void *self_in) {
frequencyio_frequencyin_obj_t* self = self_in;
frequencyio_frequencyin_obj_t * self = self_in;
// reset counter
pcnt_counter_clear(self->unit);

Expand All @@ -41,18 +41,26 @@ static void IRAM_ATTR pcnt_overflow_handler(void *self_in) {
}

static void IRAM_ATTR timer_interrupt_handler(void *self_in) {
frequencyio_frequencyin_obj_t* self = self_in;
frequencyio_frequencyin_obj_t * self = self_in;
// get counter value
int16_t count;
pcnt_get_counter_value(self->unit, &count);
self->frequency = count / 2.0 / self->capture_period;
self->frequency = ((count / 2.0) + (self->multiplier * INT16_MAX / 4.0)) / (self->capture_period);

// reset multiplier
self->multiplier = 0;

// reset counter
pcnt_counter_clear(self->unit);

// reset interrupt
TIMERG0.int_clr.t0 = 1;
TIMERG0.hw_timer[0].config.alarm_en = 1;
timg_dev_t *device = self->timer.group ? &(TIMERG1) : &(TIMERG0);
if (self->timer.idx) {
device->int_clr.t1 = 1;
} else {
device->int_clr.t0 = 1;
}
device->hw_timer[self->timer.idx].config.alarm_en = 1;
}

static void init_pcnt(frequencyio_frequencyin_obj_t* self) {
Expand All @@ -70,7 +78,7 @@ static void init_pcnt(frequencyio_frequencyin_obj_t* self) {
.counter_l_lim = 0,
};

// Initialize PCNT unit
// initialize PCNT
const int8_t unit = peripherals_pcnt_init(pcnt_config);
if (unit == -1) {
mp_raise_RuntimeError(translate("All PCNT units in use"));
Expand Down Expand Up @@ -98,15 +106,22 @@ static void init_timer(frequencyio_frequencyin_obj_t* self) {
.divider = 80 // 1 us per tick
};

// Initialize timer module
timer_init(TIMER_GROUP_0, TIMER_0, &config);
timer_set_counter_value(TIMER_GROUP_0, TIMER_0, 0);
timer_set_alarm_value(TIMER_GROUP_0, TIMER_0, self->capture_period * 1000000);
timer_isr_register(TIMER_GROUP_0, TIMER_0, timer_interrupt_handler, (void *)self, ESP_INTR_FLAG_IRAM, &self->handle);
timer_enable_intr(TIMER_GROUP_0, TIMER_0);
// initialize Timer
peripherals_timer_init(&config, &self->timer);
if (self->timer.idx == TIMER_MAX || self->timer.group == TIMER_GROUP_MAX) {
mp_raise_RuntimeError(translate("All timers in use"));
}

timer_idx_t idx = self->timer.idx;
timer_group_t group = self->timer.group;

// enable timer interrupt
timer_set_alarm_value(group, idx, self->capture_period * 1000000);
timer_isr_register(group, idx, timer_interrupt_handler, (void *)self, ESP_INTR_FLAG_IRAM, &self->handle);
timer_enable_intr(group, idx);

// Start timer
timer_start(TIMER_GROUP_0, TIMER_0);
// start timer
timer_start(self->timer.group, self->timer.idx);
}

void common_hal_frequencyio_frequencyin_construct(frequencyio_frequencyin_obj_t* self,
Expand Down Expand Up @@ -137,31 +152,31 @@ void common_hal_frequencyio_frequencyin_deinit(frequencyio_frequencyin_obj_t* se
}
reset_pin_number(self->pin);
peripherals_pcnt_deinit(&self->unit);
timer_deinit(TIMER_GROUP_0, TIMER_0);
peripherals_timer_deinit(&self->timer);
if (self->handle) {
esp_intr_free(self->handle);
self->handle = NULL;
}
}

uint32_t common_hal_frequencyio_frequencyin_get_item(frequencyio_frequencyin_obj_t* self) {
return (self->frequency + (self->multiplier * INT16_MAX));
return self->frequency;
}

void common_hal_frequencyio_frequencyin_pause(frequencyio_frequencyin_obj_t* self) {
pcnt_counter_pause(self->unit);
timer_pause(TIMER_GROUP_0, TIMER_0);
timer_pause(self->timer.group, self->timer.idx);
}

void common_hal_frequencyio_frequencyin_resume(frequencyio_frequencyin_obj_t* self) {
pcnt_counter_resume(self->unit);
timer_start(TIMER_GROUP_0, TIMER_0);
timer_start(self->timer.group, self->timer.idx);
}

void common_hal_frequencyio_frequencyin_clear(frequencyio_frequencyin_obj_t* self) {
self->frequency = 0;
pcnt_counter_clear(self->unit);
timer_set_counter_value(TIMER_GROUP_0, TIMER_0, 0);
timer_set_counter_value(self->timer.group, self->timer.idx, 0);
}

uint16_t common_hal_frequencyio_frequencyin_get_capture_period(frequencyio_frequencyin_obj_t *self) {
Expand All @@ -174,5 +189,5 @@ void common_hal_frequencyio_frequencyin_set_capture_period(frequencyio_frequency
}
self->capture_period = capture_period;
common_hal_frequencyio_frequencyin_clear(self);
timer_set_alarm_value(TIMER_GROUP_0, TIMER_0, capture_period * 1000000);
timer_set_alarm_value(self->timer.group, self->timer.idx, capture_period * 1000000);
}
5 changes: 3 additions & 2 deletions ports/esp32s2/common-hal/frequencyio/FrequencyIn.h
Original file line number Diff line number Diff line change
Expand Up @@ -28,16 +28,17 @@
#define MICROPY_INCLUDED_ESP32S2_COMMON_HAL_FREQUENCYIO_FREQUENCYIN_H

#include "py/obj.h"
#include "driver/timer.h"
#include "peripherals/pcnt.h"
#include "peripherals/timer.h"

typedef struct {
mp_obj_base_t base;
pcnt_unit_t unit;
timer_index_t timer;
intr_handle_t handle;
uint8_t pin;
uint8_t multiplier;
uint16_t frequency;
uint32_t frequency;
uint16_t capture_period;
} frequencyio_frequencyin_obj_t;

Expand Down

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