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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2020 microDev
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "shared-bindings/frequencyio/FrequencyIn.h"
#include "py/runtime.h"
static void IRAM_ATTR pcnt_overflow_handler(void *self_in) {
frequencyio_frequencyin_obj_t *self = self_in;
// reset counter
pcnt_counter_clear(self->unit);
// increase multiplier
self->multiplier++;
// reset interrupt
PCNT.int_clr.val = BIT(self->unit);
}
static void IRAM_ATTR timer_interrupt_handler(void *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->multiplier * INT16_MAX / 4.0)) / (self->capture_period);
// reset multiplier
self->multiplier = 0;
// reset counter
pcnt_counter_clear(self->unit);
// reset interrupt
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) {
// Prepare configuration for the PCNT unit
const pcnt_config_t pcnt_config = {
// Set PCNT input signal and control GPIOs
.pulse_gpio_num = self->pin,
.ctrl_gpio_num = PCNT_PIN_NOT_USED,
.channel = PCNT_CHANNEL_0,
// What to do on the positive / negative edge of pulse input?
.pos_mode = PCNT_COUNT_INC, // count both rising and falling edges
.neg_mode = PCNT_COUNT_INC,
// Set counter limit
.counter_h_lim = INT16_MAX,
.counter_l_lim = 0,
};
// initialize PCNT
const int8_t unit = peripherals_pcnt_init(pcnt_config);
if (unit == -1) {
mp_raise_RuntimeError(translate("All PCNT units in use"));
}
// set the GPIO back to high-impedance, as pcnt_unit_config sets it as pull-up
gpio_set_pull_mode(self->pin, GPIO_FLOATING);
self->unit = (pcnt_unit_t)unit;
// enable pcnt interrupt
pcnt_event_enable(self->unit, PCNT_EVT_H_LIM);
pcnt_isr_register(pcnt_overflow_handler, (void *)self, ESP_INTR_FLAG_IRAM, &self->handle);
pcnt_intr_enable(self->unit);
}
static void init_timer(frequencyio_frequencyin_obj_t *self) {
// Prepare configuration for the timer module
const timer_config_t config = {
.alarm_en = true,
.counter_en = false,
.intr_type = TIMER_INTR_LEVEL,
.counter_dir = TIMER_COUNT_UP,
.auto_reload = true,
.divider = 80 // 1 us per tick
};
// 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(self->timer.group, self->timer.idx);
}
void common_hal_frequencyio_frequencyin_construct(frequencyio_frequencyin_obj_t *self,
const mcu_pin_obj_t *pin, const uint16_t capture_period) {
if ((capture_period == 0) || (capture_period > 500)) {
mp_raise_ValueError(translate("Invalid capture period. Valid range: 1 - 500"));
}
self->pin = pin->number;
self->handle = NULL;
self->multiplier = 0;
self->capture_period = capture_period;
// initialize pcnt and timer
init_pcnt(self);
init_timer(self);
claim_pin(pin);
}
bool common_hal_frequencyio_frequencyin_deinited(frequencyio_frequencyin_obj_t *self) {
return self->unit == PCNT_UNIT_MAX;
}
void common_hal_frequencyio_frequencyin_deinit(frequencyio_frequencyin_obj_t *self) {
if (common_hal_frequencyio_frequencyin_deinited(self)) {
return;
}
reset_pin_number(self->pin);
peripherals_pcnt_deinit(&self->unit);
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;
}
void common_hal_frequencyio_frequencyin_pause(frequencyio_frequencyin_obj_t *self) {
pcnt_counter_pause(self->unit);
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(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(self->timer.group, self->timer.idx, 0);
}
uint16_t common_hal_frequencyio_frequencyin_get_capture_period(frequencyio_frequencyin_obj_t *self) {
return self->capture_period;
}
void common_hal_frequencyio_frequencyin_set_capture_period(frequencyio_frequencyin_obj_t *self, uint16_t capture_period) {
if ((capture_period == 0) || (capture_period > 500)) {
mp_raise_ValueError(translate("Invalid capture period. Valid range: 1 - 500"));
}
self->capture_period = capture_period;
common_hal_frequencyio_frequencyin_clear(self);
timer_set_alarm_value(self->timer.group, self->timer.idx, capture_period * 1000000);
}
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