main/sdm_led_example_main.c (sdm_led sample)

/* * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD * * SPDX-License-Identifier: Unlicense OR CC0-1.0 */ #include "freertos/FreeRTOS.h" #include "freertos/task.h" #include "esp_log.h" #include "driver/sdm.h" #define EXAMPLE_SIGMA_DELTA_GPIO_NUM 0 #define EXAMPLE_LED_DIM_PERIOD_MS 1000 #define EXAMPLE_LED_DIM_DELAY_MS 10 #define EXAMPLE_LED_DIM_DUTY_STEP 2 #define EXAMPLE_LED_DIM_DUTY_MAX 90 #define EXAMPLE_LED_DIM_DUTY_MIN (EXAMPLE_LED_DIM_DUTY_MAX - EXAMPLE_LED_DIM_PERIOD_MS / EXAMPLE_LED_DIM_DELAY_MS * EXAMPLE_LED_DIM_DUTY_STEP) static const char *TAG = "sdm_led"; void app_main(void) { ESP_LOGI(TAG, "Install sigma delta channel"); sdm_channel_handle_t sdm_chan = NULL; sdm_config_t config = { .clk_src = SDM_CLK_SRC_DEFAULT, .gpio_num = EXAMPLE_SIGMA_DELTA_GPIO_NUM, .sample_rate_hz = 1 * 1000 * 1000, // 1MHz sample rate }; ESP_ERROR_CHECK(sdm_new_channel(&config, &sdm_chan)); ESP_LOGI(TAG, "Enable sigma delta channel"); ESP_ERROR_CHECK(sdm_channel_enable(sdm_chan)); ESP_LOGI(TAG, "Change duty cycle continuously"); int8_t duty = 0; int step = EXAMPLE_LED_DIM_DUTY_STEP; while (1) { ESP_ERROR_CHECK(sdm_channel_set_pulse_density(sdm_chan, duty)); /* By changing delay time, you can change the blink frequency of LED */ vTaskDelay(pdMS_TO_TICKS(EXAMPLE_LED_DIM_DELAY_MS)); duty += step; if (duty == EXAMPLE_LED_DIM_DUTY_MAX || duty == EXAMPLE_LED_DIM_DUTY_MIN) { step *= -1; } } }