110 lines
4.3 KiB
C
110 lines
4.3 KiB
C
/*
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* SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
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*
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* SPDX-License-Identifier: CC0-1.0
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <math.h>
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#include <assert.h>
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#include "freertos/FreeRTOS.h"
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#include "freertos/task.h"
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#include "freertos/queue.h"
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#include "driver/gpio.h"
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#include "driver/gptimer.h"
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#include "driver/dac_oneshot.h"
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#include "esp_log.h"
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#include "dac_continuous_example.h"
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#define EXAMPLE_TIMER_RESOLUTION 1000000 // 1MHz，1个tick = 1us
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#define EXAMPLE_WAVE_FREQ_HZ 50 // 默认波形频率50Hz，不能太高
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#define EXAMPLE_CONVERT_FREQ_HZ (EXAMPLE_ARRAY_LEN * EXAMPLE_WAVE_FREQ_HZ) // DAC转换波形数组中每个数据的频率
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#define EXAMPLE_TIMER_ALARM_COUNT (EXAMPLE_TIMER_RESOLUTION / EXAMPLE_CONVERT_FREQ_HZ) // 触发定时器报警回调的计数值
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static const char *TAG = "dac continuous(timer)";
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static const char wav_name[DAC_WAVE_MAX][15] = {"sine", "triangle", "sawtooth", "square"};
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static dac_oneshot_handle_t chan0_handle;
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static dac_oneshot_handle_t chan1_handle;
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extern uint8_t sin_wav[EXAMPLE_ARRAY_LEN]; // 用于存储正弦波值
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extern uint8_t tri_wav[EXAMPLE_ARRAY_LEN]; // 用于存储三角波值
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extern uint8_t saw_wav[EXAMPLE_ARRAY_LEN]; // 用于存储锯齿波值
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extern uint8_t squ_wav[EXAMPLE_ARRAY_LEN]; // 用于存储方波值
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/* 定时器中断服务例程 */
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static bool IRAM_ATTR on_timer_alarm_cb(gptimer_handle_t timer, const gptimer_alarm_event_data_t *edata, void *user_data)
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{
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static uint32_t point_cnt = 0; // 用于计算一个波形的输出点数
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static uint32_t index = 0; // 波形缓冲区的当前索引
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static dac_example_wave_type_t wav_sel = DAC_SINE_WAVE; // 从正弦波开始
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// 每CONFIG_EXAMPLE_WAVE_PERIOD_SEC秒切换波形
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if (point_cnt < EXAMPLE_CONVERT_FREQ_HZ * CONFIG_EXAMPLE_WAVE_PERIOD_SEC) {
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switch (wav_sel) {
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case DAC_SINE_WAVE:
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ESP_ERROR_CHECK(dac_oneshot_output_voltage(chan0_handle, sin_wav[index]));
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ESP_ERROR_CHECK(dac_oneshot_output_voltage(chan1_handle, sin_wav[index]));
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break;
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case DAC_TRIANGLE_WAVE:
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ESP_ERROR_CHECK(dac_oneshot_output_voltage(chan0_handle, tri_wav[index]));
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ESP_ERROR_CHECK(dac_oneshot_output_voltage(chan1_handle, tri_wav[index]));
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break;
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case DAC_SAWTOOTH_WAVE:
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ESP_ERROR_CHECK(dac_oneshot_output_voltage(chan0_handle, saw_wav[index]));
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ESP_ERROR_CHECK(dac_oneshot_output_voltage(chan1_handle, saw_wav[index]));
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break;
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case DAC_SQUARE_WAVE:
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ESP_ERROR_CHECK(dac_oneshot_output_voltage(chan0_handle, squ_wav[index]));
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ESP_ERROR_CHECK(dac_oneshot_output_voltage(chan1_handle, squ_wav[index]));
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break;
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default:
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break;
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}
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point_cnt++;
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index++;
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index %= EXAMPLE_ARRAY_LEN;
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} else {
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wav_sel++;
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wav_sel %= DAC_WAVE_MAX;
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point_cnt = 0;
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index = 0;
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ESP_EARLY_LOGI(TAG, "%s wave start", wav_name[wav_sel]);
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}
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return false;
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}
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void example_dac_continuous_by_timer(void)
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{
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gptimer_handle_t gptimer = NULL;
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gptimer_config_t timer_config = {
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.clk_src = GPTIMER_CLK_SRC_DEFAULT,
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.direction = GPTIMER_COUNT_UP,
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.resolution_hz = EXAMPLE_TIMER_RESOLUTION, // 1MHz，1个tick = 1us
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};
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ESP_ERROR_CHECK(gptimer_new_timer(&timer_config, &gptimer));
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dac_oneshot_config_t dac0_cfg = {
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.chan_id = DAC_CHAN_0,
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};
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ESP_ERROR_CHECK(dac_oneshot_new_channel(&dac0_cfg, &chan0_handle));
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dac_oneshot_config_t dac1_cfg = {
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.chan_id = DAC_CHAN_1,
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};
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ESP_ERROR_CHECK(dac_oneshot_new_channel(&dac1_cfg, &chan1_handle));
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example_log_info(EXAMPLE_CONVERT_FREQ_HZ, EXAMPLE_WAVE_FREQ_HZ);
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gptimer_alarm_config_t alarm_config = {
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.reload_count = 0,
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.alarm_count = EXAMPLE_TIMER_ALARM_COUNT,
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.flags.auto_reload_on_alarm = true,
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};
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gptimer_event_callbacks_t cbs = {
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.on_alarm = on_timer_alarm_cb,
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};
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ESP_ERROR_CHECK(gptimer_register_event_callbacks(gptimer, &cbs, NULL));
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ESP_ERROR_CHECK(gptimer_set_alarm_action(gptimer, &alarm_config));
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ESP_ERROR_CHECK(gptimer_enable(gptimer));
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ESP_ERROR_CHECK(gptimer_start(gptimer));
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}
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