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55 lines
1.5 KiB
C
55 lines
1.5 KiB
C
/* Sigma-delta Example
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This example code is in the Public Domain (or CC0 licensed, at your option.)
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Unless required by applicable law or agreed to in writing, this
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software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
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CONDITIONS OF ANY KIND, either express or implied.
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*/
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#include <stdio.h>
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#include "freertos/FreeRTOS.h"
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#include "freertos/task.h"
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#include "esp_system.h"
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#include "driver/sigmadelta.h"
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/*
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* This test code will configure sigma-delta and set GPIO4 as a signal output pin.
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* If you connect this GPIO4 with a LED, you will see the LED blinking slowly.
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*/
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/*
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* Configure and initialize the sigma delta modulation
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* on channel 0 to output signal on GPIO4
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*/
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static void sigmadelta_example_init(void)
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{
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sigmadelta_config_t sigmadelta_cfg = {
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.channel = SIGMADELTA_CHANNEL_0,
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.sigmadelta_prescale = 80,
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.sigmadelta_duty = 0,
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.sigmadelta_gpio = GPIO_NUM_4,
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};
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sigmadelta_config(&sigmadelta_cfg);
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}
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/*
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* Perform the sigma-delta modulation test
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* by changing the duty of the output signal.
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*/
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void app_main(void)
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{
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sigmadelta_example_init();
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int8_t duty = 0;
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int inc = 1;
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while (1) {
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sigmadelta_set_duty(SIGMADELTA_CHANNEL_0, duty);
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/* By changing delay time, you can change the blink frequency of LED */
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vTaskDelay(10 / portTICK_PERIOD_MS);
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duty += inc;
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if (duty == 127 || duty == -127) {
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inc = (-1) * inc;
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}
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}
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}
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