1. 定时器定时回调LED及采集AHT30环境温湿度数据代码
C
#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_timer.h"
#include "esp_log.h"
#include "driver/gpio.h"
#include "driver/i2c_master.h"
// -------------------------------------------------------
// LED 配置
// -------------------------------------------------------
#define LED_GPIO GPIO_NUM_38
#define BLINK_INTERVAL_US (5 * 1000000) // 5 秒触发一次点亮
#define LED_ON_DURATION_US (1 * 1000000) // 亮 1 秒后熄灭
// -------------------------------------------------------
// I2C / AHT30 配置
// -------------------------------------------------------
#define I2C_MASTER_SCL_IO 5
#define I2C_MASTER_SDA_IO 6
#define AHT30_ADDR 0x38
#define AHT30_INTERVAL_US (3 * 1000000) // 每 3 秒采集一次
static const char *TAG_LED = "ESP_TIMER_LED";
static const char *TAG_AHT30 = "AHT30";
// -------------------------------------------------------
// 定时器句柄
// -------------------------------------------------------
static esp_timer_handle_t led_on_timer_handle = NULL;
static esp_timer_handle_t led_off_timer_handle = NULL;
static esp_timer_handle_t aht30_timer_handle = NULL;
// -------------------------------------------------------
// AHT30 设备句柄（全局，供定时器回调使用）
// -------------------------------------------------------
static i2c_master_dev_handle_t aht30_device_handle = NULL;
// -------------------------------------------------------
// 回调 A：点亮 LED，启动 1 秒熄灭定时器
// -------------------------------------------------------
static void led_on_callback(void *arg)
{
gpio_set_level(LED_GPIO, 1);
ESP_LOGI(TAG_LED, "LED ON");
ESP_ERROR_CHECK(esp_timer_start_once(led_off_timer_handle, LED_ON_DURATION_US));
}
// -------------------------------------------------------
// 回调 B：熄灭 LED，重新启动 5 秒触发定时器
// -------------------------------------------------------
static void led_off_callback(void *arg)
{
gpio_set_level(LED_GPIO, 0);
ESP_LOGI(TAG_LED, "LED OFF");
ESP_ERROR_CHECK(esp_timer_start_once(led_on_timer_handle, BLINK_INTERVAL_US));
}
// -------------------------------------------------------
// 回调 C：每 3 秒触发，读取 AHT30 温湿度
// 注意：此回调运行在 esp_timer task 中，可以使用 vTaskDelay
// -------------------------------------------------------
static void aht30_read_callback(void *arg)
{
// 发送触发测量命令
uint8_t trigger_cmd[3] = {0xAC, 0x33, 0x00};
esp_err_t ret = i2c_master_transmit(aht30_device_handle, trigger_cmd,
sizeof(trigger_cmd), -1);
if (ret != ESP_OK) {
ESP_LOGE(TAG_AHT30, "Transmit failed: %s", esp_err_to_name(ret));
return;
}
// 等待 AHT30 完成测量（典型 80ms，这里用 100ms）
vTaskDelay(pdMS_TO_TICKS(100));
// 读取 6 字节数据
uint8_t data[6] = {0};
ret = i2c_master_receive(aht30_device_handle, data, sizeof(data), -1);
if (ret != ESP_OK) {
ESP_LOGE(TAG_AHT30, "Receive failed: %s", esp_err_to_name(ret));
return;
}
// 解析湿度（20 位原始值）
uint32_t humidity_raw = ((uint32_t)data[1] << 12)
| ((uint32_t)data[2] << 4)
| (data[3] >> 4);
// 解析温度（20 位原始值）
uint32_t temperature_raw = (((uint32_t)data[3] & 0x0F) << 16)
| ((uint32_t)data[4] << 8)
| data[5];
float humidity = (float)humidity_raw / 1048576.0f * 100.0f;
float temperature = (float)temperature_raw / 1048576.0f * 200.0f - 50.0f;
ESP_LOGI(TAG_AHT30, "Temperature: %.2f °C, Humidity: %.2f %%",
temperature, humidity);
}
// -------------------------------------------------------
// app_main
// -------------------------------------------------------
void app_main(void)
{
// =====================================================
// 1. 初始化 LED GPIO
// =====================================================
gpio_config_t io_conf = {
.pin_bit_mask = (1ULL << LED_GPIO),
.mode = GPIO_MODE_OUTPUT,
.pull_up_en = GPIO_PULLUP_DISABLE,
.pull_down_en = GPIO_PULLDOWN_DISABLE,
.intr_type = GPIO_INTR_DISABLE,
};
gpio_config(&io_conf);
gpio_set_level(LED_GPIO, 0);
// =====================================================
// 2. 初始化 I2C 总线
// =====================================================
i2c_master_bus_config_t bus_config = {
.i2c_port = I2C_NUM_0,
.sda_io_num = I2C_MASTER_SDA_IO,
.scl_io_num = I2C_MASTER_SCL_IO,
.clk_source = I2C_CLK_SRC_DEFAULT,
.glitch_ignore_cnt = 7,
.flags.enable_internal_pullup = true,
};
i2c_master_bus_handle_t bus_handle;
ESP_ERROR_CHECK(i2c_new_master_bus(&bus_config, &bus_handle));
// =====================================================
// 3. 挂载 AHT30 设备
// =====================================================
i2c_device_config_t aht30_dev_config = {
.dev_addr_length = I2C_ADDR_BIT_LEN_7,
.device_address = AHT30_ADDR,
.scl_speed_hz = 100000,
.flags.disable_ack_check = false,
};
ESP_ERROR_CHECK(i2c_master_bus_add_device(bus_handle,
&aht30_dev_config,
&aht30_device_handle));
vTaskDelay(pdMS_TO_TICKS(100)); // 等待设备稳定
// =====================================================
// 4. 创建并启动 LED 定时器
// =====================================================
const esp_timer_create_args_t led_on_args = {
.callback = &led_on_callback,
.name = "led_on_timer",
};
ESP_ERROR_CHECK(esp_timer_create(&led_on_args, &led_on_timer_handle));
const esp_timer_create_args_t led_off_args = {
.callback = &led_off_callback,
.name = "led_off_timer",
};
ESP_ERROR_CHECK(esp_timer_create(&led_off_args, &led_off_timer_handle));
// 5 秒后第一次点亮 LED
ESP_ERROR_CHECK(esp_timer_start_once(led_on_timer_handle, BLINK_INTERVAL_US));
ESP_LOGI(TAG_LED, "LED timer started");
// =====================================================
// 5. 创建并启动 AHT30 周期定时器（每 3 秒触发一次）
// =====================================================
const esp_timer_create_args_t aht30_args = {
.callback = &aht30_read_callback,
.name = "aht30_timer",
};
ESP_ERROR_CHECK(esp_timer_create(&aht30_args, &aht30_timer_handle));
// 立即触发第一次，之后每 3 秒周期触发
ESP_ERROR_CHECK(esp_timer_start_periodic(aht30_timer_handle, AHT30_INTERVAL_US));
ESP_LOGI(TAG_AHT30, "AHT30 timer started");
// app_main 返回，定时器在后台继续运行
}