esp-idf/examples/peripherals/analog_comparator/main/ana_cmpr_example_etm.c

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5.7 KiB
C

/*
* SPDX-FileCopyrightText: 2023-2024 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Unlicense OR CC0-1.0
*/
#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/gpio.h"
#include "driver/ana_cmpr.h"
#include "driver/ana_cmpr_etm.h"
#include "driver/gpio_etm.h"
#include "esp_etm.h"
#include "esp_log.h"
#include "ana_cmpr_example_main.h"
static const char *TAG = "ana_cmpr_example";
static void example_etm_bind_ana_cmpr_event_with_gpio_task(ana_cmpr_handle_t cmpr)
{
/* Allocate the analog comparator positive & negative cross events */
esp_etm_event_handle_t cmpr_pos_evt = NULL;
esp_etm_event_handle_t cmpr_neg_evt = NULL;
ana_cmpr_etm_event_config_t evt_cfg = {
.event_type = ANA_CMPR_EVENT_POS_CROSS,
};
ESP_ERROR_CHECK(ana_cmpr_new_etm_event(cmpr, &evt_cfg, &cmpr_pos_evt));
evt_cfg.event_type = ANA_CMPR_EVENT_NEG_CROSS;
ESP_ERROR_CHECK(ana_cmpr_new_etm_event(cmpr, &evt_cfg, &cmpr_neg_evt));
/* Allocate the GPIO set & clear tasks */
esp_etm_task_handle_t gpio_set_task = NULL;
esp_etm_task_handle_t gpio_clr_task = NULL;
gpio_etm_task_config_t task_cfg = {};
task_cfg.actions[0] = GPIO_ETM_TASK_ACTION_SET;
task_cfg.actions[1] = GPIO_ETM_TASK_ACTION_CLR;
ESP_ERROR_CHECK(gpio_new_etm_task(&task_cfg, &gpio_set_task, &gpio_clr_task));
/* Add task to the monitor GPIO */
ESP_ERROR_CHECK(gpio_etm_task_add_gpio(gpio_set_task, EXAMPLE_MONITOR_GPIO_NUM));
ESP_ERROR_CHECK(gpio_etm_task_add_gpio(gpio_clr_task, EXAMPLE_MONITOR_GPIO_NUM));
/* Allocate the Event Task Matrix channels */
esp_etm_channel_handle_t etm_pos_handle;
esp_etm_channel_handle_t etm_neg_handle;
esp_etm_channel_config_t etm_cfg = {};
ESP_ERROR_CHECK(esp_etm_new_channel(&etm_cfg, &etm_pos_handle));
ESP_ERROR_CHECK(esp_etm_new_channel(&etm_cfg, &etm_neg_handle));
/* Bind the events and tasks */
ESP_ERROR_CHECK(esp_etm_channel_connect(etm_pos_handle, cmpr_pos_evt, gpio_set_task));
ESP_ERROR_CHECK(esp_etm_channel_connect(etm_neg_handle, cmpr_neg_evt, gpio_clr_task));
/* Enable the ETM channels */
ESP_ERROR_CHECK(esp_etm_channel_enable(etm_pos_handle));
ESP_ERROR_CHECK(esp_etm_channel_enable(etm_neg_handle));
}
ana_cmpr_handle_t example_init_analog_comparator_etm(void)
{
/* Step 0: Show the source channel and reference channel GPIO */
int src_gpio = -1;
int ext_ref_gpio = -1;
ESP_ERROR_CHECK(ana_cmpr_get_gpio(EXAMPLE_ANA_CMPR_UNIT, ANA_CMPR_SOURCE_CHAN, &src_gpio));
ESP_ERROR_CHECK(ana_cmpr_get_gpio(EXAMPLE_ANA_CMPR_UNIT, ANA_CMPR_EXT_REF_CHAN, &ext_ref_gpio));
ESP_LOGI(TAG, "Analog Comparator source gpio %d, external reference gpio %d", src_gpio, ext_ref_gpio);
ana_cmpr_handle_t cmpr = NULL;
#if CONFIG_EXAMPLE_INTERNAL_REF
/* Step 1: Allocate the new analog comparator unit */
ana_cmpr_config_t config = {
.unit = EXAMPLE_ANA_CMPR_UNIT,
.clk_src = ANA_CMPR_CLK_SRC_DEFAULT,
.ref_src = ANA_CMPR_REF_SRC_INTERNAL,
.cross_type = ANA_CMPR_CROSS_ANY,
};
ESP_ERROR_CHECK(ana_cmpr_new_unit(&config, &cmpr));
ESP_LOGI(TAG, "Allocate Analog Comparator with internal reference");
/* Step 1.1: As we are using the internal reference source, we need to configure the internal reference */
ana_cmpr_internal_ref_config_t ref_cfg = {
.ref_volt = ANA_CMPR_REF_VOLT_50_PCT_VDD,
};
ESP_ERROR_CHECK(ana_cmpr_set_internal_reference(cmpr, &ref_cfg));
#else
/* Step 1: Allocate the new analog comparator unit */
ana_cmpr_config_t config = {
.unit = EXAMPLE_ANA_CMPR_UNIT,
.clk_src = ANA_CMPR_CLK_SRC_DEFAULT,
.ref_src = ANA_CMPR_REF_SRC_EXTERNAL,
.cross_type = ANA_CMPR_CROSS_ANY,
};
ESP_ERROR_CHECK(ana_cmpr_new_unit(&config, &cmpr));
ESP_LOGI(TAG, "Allocate Analog Comparator with external reference");
#endif // CONFIG_EXAMPLE_INTERNAL_REF
/* Step 2: (Optional) Set the debounce configuration
* It's an optional configuration, if the wait time is set in debounce configuration,
* the cross interrupt will be disabled temporary after it is triggered, and it will be enabled
* automatically enabled after `wait_us`, so that the duplicate interrupts
* can be suppressed while the source signal crossing the reference signal. */
ana_cmpr_debounce_config_t dbc_cfg = {
/* Normally the `wait_us` is related to the relative frequency between the source and reference signal
* comparing to another one. This example adopts an approximate frequency as the relative signal
* frequency, and set the default wait time to EXAMPLE_WAIT_TIME_PROP of the relative signal period.
* We need to estimate an appropriate `freq_approx` and EXAMPLE_WAIT_TIME_PROP
* to make sure the interrupt neither triggers duplicate interrupts, nor misses the next crossing interrupt.
* Here we take 1 KHz for example */
.wait_us = EXAMPLE_WAITE_TIME_US(1000),
};
ESP_ERROR_CHECK(ana_cmpr_set_debounce(cmpr, &dbc_cfg));
/* Step 3: Enable the analog comparator unit */
ESP_ERROR_CHECK(ana_cmpr_enable(cmpr));
#if CONFIG_EXAMPLE_INTERNAL_REF
ESP_LOGI(TAG, "Analog comparator enabled, reference voltage: %d%% * VDD", (int)ref_cfg.ref_volt * 10);
#else
ESP_LOGI(TAG, "Analog comparator enabled, external reference selected");
#endif
return cmpr;
}
void example_analog_comparator_etm_app(void)
{
/* Initialize GPIO to monitor the comparator interrupt */
example_init_monitor_gpio();
/* Initialize Analog Comparator */
ana_cmpr_handle_t cmpr = example_init_analog_comparator_etm();
/* Connect the analog comparator events and gpio tasks via ETM channels */
example_etm_bind_ana_cmpr_event_with_gpio_task(cmpr);
}