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XIAO ESP32S3(Sense) 与 FreeRTOS

本 wiki 介绍了 Seeed Studio XIAO ESP32S3 对 FreeRTOS 的支持。通过本指南的帮助，您将能够利用该开发板的可用功能集。

什么是 FreeRTOS​

pir

FreeRTOS 是一个 C 库集合，由实时内核和一组实现互补功能的模块化库组成。FreeRTOS 内核是一个实时内核（或实时调度器），使基于 FreeRTOS 构建的应用程序能够满足其硬实时要求。它使应用程序能够组织为独立执行线程的集合。

参考：掌握 FreeRTOS 实时内核

FreeRTOS 移植​

FreeRTOS 是一个开源 RTOS（实时操作系统）内核，作为组件集成到 ESP-IDF 中。因此，所有 ESP-IDF 应用程序和许多 ESP-IDF 组件都是基于 FreeRTOS 编写的。FreeRTOS 内核已移植到 ESP 芯片的所有可用架构（即 Xtensa 和 RISC-V）。

我们将使用 FreeRTOS 的 ESP IDF 移植版本。

硬件准备​

我使用的是 Seed Studio XIAO ESP32S3 Sense 以及板载摄像头、麦克风和 SD 卡读卡器，还有 ESP32S3 的 WiFi 功能。

Seeed Studio XIAO ESP32S3(Sense)
立即获取 🖱️

附加组件​

软件准备​

我使用的是 Visual Studio Code (Windows) 配合 ESP-IDF。

  1. VSCode 安装
  2. ESP-IDF 安装指南
  3. Git 仓库
VS CodeESP-IDF for VSCode
下载 VSCode⏬
ESP-IDF 安装 ⏬

开始使用​

设置 ESP-IDF​

在设置好 Visual Studio 扩展 后，打开终端并粘贴以下命令，以便从普通终端环境（VScode 外部）访问 ESP-IDF 命令行工具。

note

正常安装 VS-Code 的 ESP-IDF 扩展将处理 90% 的使用情况，只有在需要在环境外部使用 ESP 命令行工具时才执行以下步骤。

PowerShell (Windows)

.$HOME\esp\v5.3\esp-idf\export.ps1
info

".$HOME\esp\v5.3\esp-idf" 可能因用户而异。这是默认安装路径。
请将其替换为您设备上的安装路径。

tip

为了避免重复设置，请以管理员模式启动 PowerShell 并输入以下命令

notepad $PSHOME\Profile.ps1

一个记事本实例将会打开。将导出的shell命令粘贴到记事本中并保存。 打开一个PowerShell实例，它应该有接近以下的输出。

Done! You can now compile ESP-IDF projects.

如果一切操作正确，以下命令：

idf.py

应显示以下输出：

Usage: idf.py [OPTIONS] COMMAND1 [ARGS]... [COMMAND2 [ARGS]...]...

  ESP-IDF CLI build management tool. For commands that are not known to idf.py an attempt to execute it as a build
  system target will be made. Selected target: None

什么是任务？​

任务是处理器被请求执行的小型函数/作业，带有一组设置。任务的范围可以从小型函数到无限循环函数。
任务是 ESP-IDF 应用程序中执行的基本单元。它们本质上是与其他任务并发运行的函数。这允许高效的多任务处理和响应性。

什么是任务属性？​

由于这个主题的广泛性，我将只涵盖我们在本指南中将使用的一些属性。

  • TaskFunction：这是包含任务实际逻辑的函数。它是任务执行的入口点。
  • StackSize：这指定为任务堆栈分配的内存量。堆栈用于存储局部变量、函数返回地址和临时数据。
  • TaskPriority：这决定了任务相对于其他任务的重要性。高优先级任务比低优先级任务有更大的机会被优先执行。
  • TaskParameters：这些是可选参数，可以在创建任务函数时传递给它。它们可以用于为任务提供额外的上下文或配置。
  • CoreAffinity：这指定任务应该分配给哪个 CPU 核心。在具有多个核心的系统中，这可以用于优化性能或平衡工作负载。

创建任务​

要在 FreeRTOS 中创建任务，使用 xTaskCreate 函数。此函数接受几个参数，包括任务函数、任务名称、堆栈大小、参数、优先级和指向创建任务的句柄。

TaskHandle_t task;
xTaskCreate(
        taskFunction,             /* Function that implements the task. */
        "taskName",               /* Text name for the task. */
        configMINIMAL_STACK_SIZE, /* Stack size in words, or bytes. */
        NULL,                     /* Parameter passed into the task. */
        tskIDLE_PRIORITY,         /* Priority at which the task is created. */
        &task                     /* Used to pass out the created task's handle. */
        );

创建固定到核心的任务​

要创建一个任务并将其固定到特定核心（仅当使用的芯片是双核时），需要使用 xTaskCreatePinnedToCore 函数。此函数与 xTaskCreate 类似，但包含一个用于指定核心的附加参数。

TaskHandle_t task;
xTaskCreatePinnedToCore(
        taskFunction,             /* Function that implements the task. */
        "taskName",               /* Text name for the task. */
        configMINIMAL_STACK_SIZE, /* Stack size in words, or bytes. */
        NULL,                     /* Parameter passed into the task. */
        tskIDLE_PRIORITY,         /* Priority at which the task is created. */
        &task,                    /* Used to pass out the created task's handle. */
        0);                       /* Core ID */

Task function call​

任务函数是将由任务执行的实际代码。

void taskFunction(void * pvParameters) {
  /*
  Function definition goes here
  */
}

任务的可视化​

我正在创建四个简单的任务来可视化 FreeRTOS 的工作原理。

pir

可视化表示​

CPU0
-----
taskFunction1 (1000ms delay)

CPU1
-----
taskFunction2 (500ms delay)
taskFunction3 (500ms delay)
taskFunction4 (500ms delay)

Code​

#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "sdkconfig.h"
#include "esp_log.h"

TaskHandle_t task1,task2,task3,task4;

void taskFunction1(void * pvParameters) {
    while (true) {
        ESP_LOGI("Task1", "Hello from task 1");
        vTaskDelay(pdMS_TO_TICKS(1000)); // Add a delay to avoid overwhelming the output
    }
}

void taskFunction2(void * pvParameters) {
    while (true) {
        ESP_LOGI("Task2", "Hello from task 2");
        vTaskDelay(pdMS_TO_TICKS(500)); // Add a delay to avoid overwhelming the output
    }
}

void taskFunction3(void * pvParameters) {
    while (true) {
        ESP_LOGI("Task3", "Hello from task 3");
        vTaskDelay(pdMS_TO_TICKS(500)); // Add a delay to avoid overwhelming the output
    }
}

void taskFunction4(void * pvParameters) {
    while (true) {
        ESP_LOGI("Task4", "Hello from task 4");
        vTaskDelay(pdMS_TO_TICKS(500)); // Add a delay to avoid overwhelming the output
    }
}

void app_main(void) {
    xTaskCreatePinnedToCore(
        taskFunction1, /* Function that implements the task. */
        "task_1",        /* Text name for the task. */
        configMINIMAL_STACK_SIZE, /* Stack size in words, not bytes. */
        NULL,            /* Parameter passed into the task. */
        tskIDLE_PRIORITY, /* Priority at which the task is created. */
        &task1,         /* Used to pass out the created task's handle. */
        0);              /* Core ID */

    xTaskCreatePinnedToCore(
        taskFunction2, /* Function that implements the task. */
        "task_2",        /* Text name for the task. */
        configMINIMAL_STACK_SIZE, /* Stack size in words, not bytes. */
        NULL,            /* Parameter passed into the task. */
        tskIDLE_PRIORITY, /* Priority at which the task is created. */
        &task2,         /* Used to pass out the created task's handle. */
        1);              /* Core ID */

    xTaskCreatePinnedToCore(
        taskFunction3, /* Function that implements the task. */
        "task_3",        /* Text name for the task. */
        configMINIMAL_STACK_SIZE, /* Stack size in words, not bytes. */
        NULL,            /* Parameter passed into the task. */
        tskIDLE_PRIORITY, /* Priority at which the task is created. */
        &task3,         /* Used to pass out the created task's handle. */
        1);              /* Core ID */

    xTaskCreatePinnedToCore(
        taskFunction4, /* Function that implements the task. */
        "task_4",        /* Text name for the task. */
        configMINIMAL_STACK_SIZE, /* Stack size in words, not bytes. */
        NULL,            /* Parameter passed into the task. */
        tskIDLE_PRIORITY, /* Priority at which the task is created. */
        &task4,         /* Used to pass out the created task's handle. */
        1);              /* Core ID */
}
tip

configMINIMAL_STACK_SIZE 可以在 sdkconfig 中更改。

  1. 四个任务：代码定义了四个任务：taskFunction1、taskFunction2、taskFunction3 和 taskFunction4。
  2. 任务优先级：所有任务都使用 tskIDLE_PRIORITY 创建。这意味着它们具有相同的优先级。
  3. 任务绑定：taskFunction1 绑定到 CPU0，而其他三个任务绑定到 CPU1。
  4. 任务延迟：taskFunction1 的延迟为 1000ms，而其他三个任务的延迟为 500ms。

创建 CPU0 和 CPU1 任务调度​

我已经为 CPU0 和 CPU1 创建了基本的任务调度。

CPU0 任务调度​

Task: taskFunction1
Priority: Idle (lowest)
Delay: 1000ms
Core: 0

CPU1 Task Schedule​

Tasks: taskFunction2, taskFunction3, taskFunction4
Priorities: All Idle (same priority)
Delays: 500ms for all tasks
Core: 1
info

这是一个简化的调度。实际实时系统中的任务调度会涉及更复杂的因素，如任务优先级、截止时间和资源约束。

输出
I (11412) Task1: Hello from task 1
I (11522) Task3: Hello from task 3
I (11522) Task2: Hello from task 2
I (11532) Task4: Hello from task 4
I (12032) Task3: Hello from task 3
I (12032) Task2: Hello from task 2
I (12042) Task4: Hello from task 4
I (12422) Task1: Hello from task 1
I (12542) Task3: Hello from task 3
I (12542) Task2: Hello from task 2
I (12552) Task4: Hello from task 4
I (13052) Task3: Hello from task 3
I (13052) Task2: Hello from task 2
I (13062) Task4: Hello from task 4
I (13432) Task1: Hello from task 1
I (13562) Task3: Hello from task 3
I (13562) Task2: Hello from task 2
I (13572) Task4: Hello from task 4
I (14072) Task3: Hello from task 3
I (14072) Task2: Hello from task 2
I (14082) Task4: Hello from task 4

使用 FreeRTOS 进行传感器轮询​

为此，我使用了一个模拟传感器 Air Quality Sensor v1.3 以及 ESP_IDF_v5.3。

下载代码

硬件设置​

将 Xiao-S3 连接到 Grove - Expansion Board，并将 Air Quality Sensor v1.3 连接到模拟连接器。

pir

软件设置​

拉取 git 仓库后，在 VSCode 中打开文件夹。转到 View->Command Palette->ESP-IDF: Add vscode Configuration Folder。 从底部面板选择正确的 COM 端口、芯片（ESP-S3），然后构建、烧录和监控。

代码概述​

此代码旨在从传感器收集空气质量数据，处理原始数据以确定空气质量水平，并定期将结果打印到控制台。

关键组件​

  • 传感器初始化：
air_quality_sensor_t air_quality_sensor;

void sensor_setup()
{
    air_quality_sensor._io_num = ADC_CHANNEL_0;
    air_quality_sensor._adc_num = ADC_UNIT_1;
    printf("Starting Air Quality Sensor...\n");
    if(!initialize_air_quality_sensor(&air_quality_sensor))
    {
        printf("Sensor ready.\n");
    }
    else{
        printf("Sensor ERROR!\n");
    }
}

  • sensor_setup() 函数配置传感器的 I/O 引脚和 ADC 单元。

  • 它尝试使用 initialize_air_quality_sensor() 初始化传感器。

  • 如果初始化成功，传感器就准备好进行数据收集。

  • 数据收集任务：

void poll_read_air_quality_sensor(void *pvParameters)
{
    for (;;)
    {
        air_quality_sensor_slope(&air_quality_sensor);
        vTaskDelay(500 / portTICK_PERIOD_MS);
    }
}

  • 创建了 poll_read_air_quality_sensor() 任务来持续读取传感器的原始数据。

  • 它调用 air_quality_sensor_slope() 来处理原始数据并计算斜率，这是空气质量的一个指标。

  • 该任务在读取下一个数据点之前延迟 500 毫秒。

  • 数据打印任务：


void print_read_air_quality_sensor(void *pvParameters)
{
    for (;;)
    {
        char buf[40];
        air_quality_error_to_message(air_quality_sensor._air_quality,buf);
        printf("Time : %lu\tSlope : %d\tRaw Value : %d\n%s\n", (uint32_t)esp_timer_get_time() / 1000, air_quality_sensor._air_quality, air_quality_sensor._sensor_raw_value,buf);
        vTaskDelay(1000 / portTICK_PERIOD_MS);
    }
}
  • 创建 print_read_air_quality_sensor() 任务来定期打印收集的数据和计算的空气质量。
  • 它使用 air_quality_error_to_message() 检索当前时间、斜率、原始值和空气质量消息。
  • 该任务以格式化的方式将数据打印到控制台。
  • 该任务在打印下一个数据点之前延迟 1000 毫秒。

void app_main(void)
{
    sensor_setup();
    xTaskCreatePinnedToCore(
        poll_read_air_quality_sensor,   /* Function that implements the task. */
        "poll_read_air_quality_sensor", /* Text name for the task. */
        configMINIMAL_STACK_SIZE * 2,   /* Stack size in words, not bytes. */
        NULL,                           /* Parameter passed into the task. */
        tskIDLE_PRIORITY,               /* Priority at which the task is created. */
        NULL,                           /* Used to pass out the created task's handle. */
        0);                             /* Core ID */

    xTaskCreatePinnedToCore(
        print_read_air_quality_sensor,   /* Function that implements the task. */
        "print_read_air_quality_sensor", /* Text name for the task. */
        configMINIMAL_STACK_SIZE * 2,    /* Stack size in words, not bytes. */
        NULL,                            /* Parameter passed into the task. */
        tskIDLE_PRIORITY + 1,            /* Priority at which the task is created. */
        NULL,                            /* Used to pass out the created task's handle. */
        0);                              /* Core ID */
}

Output​

Time : 37207    Slope : 3       Raw Value : 273
Fresh air.
Time : 38217    Slope : 3       Raw Value : 269
Fresh air.
Time : 39227    Slope : 3       Raw Value : 274
Fresh air.
Time : 40237    Slope : 3       Raw Value : 251
Fresh air.
Time : 41247    Slope : 3       Raw Value : 276
Fresh air.
Time : 42257    Slope : 3       Raw Value : 250
Fresh air.
Time : 43267    Slope : 3       Raw Value : 236
Fresh air.
Time : 44277    Slope : 3       Raw Value : 253
Fresh air.
Time : 45287    Slope : 3       Raw Value : 245
Fresh air.
Time : 46297    Slope : 3       Raw Value : 249
Fresh air.
Time : 47307    Slope : 3       Raw Value : 244
Fresh air.
Time : 48317    Slope : 3       Raw Value : 235
Fresh air.
Time : 49327    Slope : 3       Raw Value : 239
Fresh air.
Time : 50337    Slope : 3       Raw Value : 233
Fresh air.
Time : 51347    Slope : 3       Raw Value : 235
Fresh air.

在 FreeRTOS 中使用摄像头和 SD 卡​

在这里我使用板载摄像头和 SD 卡以及 ESP_IDF_v5.3。

下载代码

硬件设置​

按照 microSD 卡指南 和 摄像头指南 将摄像头和 microSD 卡扩展板连接到

  • 格式化 microSD 卡（支持最大 32GB）
  • 将 microSD 卡连接到扩展板

设置看起来像这样：

正面背面

软件设置​

拉取 git 仓库后，在 VSCode 中打开文件夹。转到 View->Command Palette->ESP-IDF: Add vscode Configuration Folder。 从底部面板选择正确的 COM 端口、芯片（ESP-S3），然后构建、烧录和监控。

tip

如果您使用的是 OV3660 型号，您需要在 IDF 中设置它以便能够驱动它。在您的终端中输入 "idf.py menuconfig"

步骤 1步骤 2步骤 3

摄像头组件​

  • 摄像头配置：
    • 定义用于各种摄像头功能的 GPIO 引脚（PWDN、RESET、XCLK、SIOD、SIOC、Y9-Y2、VSYNC、HREF、PCLK、LED）。
    • 设置摄像头参数的默认值（例如时钟频率、帧缓冲区位置、像素格式、帧大小、JPEG 质量、帧缓冲区数量、抓取模式）。
#ifndef CAMERA_CONFIG_H
#define CAMERA_CONFIG_H

#define PWDN_GPIO_NUM     -1
#define RESET_GPIO_NUM    -1
#define XCLK_GPIO_NUM     10
#define SIOD_GPIO_NUM     40
#define SIOC_GPIO_NUM     39

#define Y9_GPIO_NUM       48
#define Y8_GPIO_NUM       11
#define Y7_GPIO_NUM       12
#define Y6_GPIO_NUM       14
#define Y5_GPIO_NUM       16
#define Y4_GPIO_NUM       18
#define Y3_GPIO_NUM       17
#define Y2_GPIO_NUM       15
#define VSYNC_GPIO_NUM    38
#define HREF_GPIO_NUM     47
#define PCLK_GPIO_NUM     13

#define LED_GPIO_NUM      21

#endif //CAMERA_CONFIG_H

  • 摄像头接口：
    声明函数 initialize_camera() 和 createCameraTask()。

  • 摄像头实现：

    • 使用定义的配置初始化摄像头。
    void initialize_camera(void)
    {
      camera_config_t camera_config = {
          .pin_pwdn = PWDN_GPIO_NUM,
          .pin_reset = RESET_GPIO_NUM,
          .pin_xclk = XCLK_GPIO_NUM,
          .pin_sccb_sda = SIOD_GPIO_NUM,
          .pin_sccb_scl = SIOC_GPIO_NUM,
          .pin_d7 = Y9_GPIO_NUM,
          .pin_d6 = Y8_GPIO_NUM,
          .pin_d5 = Y7_GPIO_NUM,
          .pin_d4 = Y6_GPIO_NUM,
          .pin_d3 = Y5_GPIO_NUM,
          .pin_d2 = Y4_GPIO_NUM,
          .pin_d1 = Y3_GPIO_NUM,
          .pin_d0 = Y2_GPIO_NUM,
          .pin_vsync = VSYNC_GPIO_NUM,
          .pin_href = HREF_GPIO_NUM,
          .pin_pclk = PCLK_GPIO_NUM,

          .xclk_freq_hz = 20000000,          // The clock frequency of the image sensor
          .fb_location = CAMERA_FB_IN_PSRAM, // Set the frame buffer storage location
          .pixel_format = PIXFORMAT_JPEG,    // The pixel format of the image: PIXFORMAT_ + YUV422|GRAYSCALE|RGB565|JPEG
          .frame_size = FRAMESIZE_UXGA,      // The resolution size of the image: FRAMESIZE_ + QVGA|CIF|VGA|SVGA|XGA|SXGA|UXGA
          .jpeg_quality = 15,                // The quality of the JPEG image, ranging from 0 to 63.
          .fb_count = 2,                     // The number of frame buffers to use.
          .grab_mode = CAMERA_GRAB_LATEST    //  The image capture mode.
      };

      esp_err_t ret = esp_camera_init(&camera_config);
      if (ret == ESP_OK)
      {
          ESP_LOGI(cameraTag, "Camera configured successful");
      }
      else
      {
          ESP_LOGI(cameraTag, "Camera configured unsuccessful");
          return;
      }
    }
    • 设置相机参数（亮度、对比度、饱和度、特效、白平衡、曝光控制、AEC、AE 级别、AEC 值、增益控制、AGC 增益、增益上限、BPC、WPC、原始 GMA、LENC、水平镜像、垂直翻转、DCW、彩条）。
    sensor_t *s = esp_camera_sensor_get();

      s->set_brightness(s, 0);                 // -2 to 2
      s->set_contrast(s, 0);                   // -2 to 2
      s->set_saturation(s, 0);                 // -2 to 2
      s->set_special_effect(s, 0);             // 0 to 6 (0 - No Effect, 1 - Negative, 2 - Grayscale, 3 - Red Tint, 4 - Green Tint, 5 - Blue Tint, 6 - Sepia)
      s->set_whitebal(s, 1);                   // 0 = disable , 1 = enable
      s->set_awb_gain(s, 1);                   // 0 = disable , 1 = enable
      s->set_wb_mode(s, 0);                    // 0 to 4 - if awb_gain enabled (0 - Auto, 1 - Sunny, 2 - Cloudy, 3 - Office, 4 - Home)
      s->set_exposure_ctrl(s, 1);              // 0 = disable , 1 = enable
      s->set_aec2(s, 0);                       // 0 = disable , 1 = enable
      s->set_ae_level(s, 0);                   // -2 to 2
      s->set_aec_value(s, 300);                // 0 to 1200
      s->set_gain_ctrl(s, 1);                  // 0 = disable , 1 = enable
      s->set_agc_gain(s, 0);                   // 0 to 30
      s->set_gainceiling(s, (gainceiling_t)0); // 0 to 6
      s->set_bpc(s, 0);                        // 0 = disable , 1 = enable
      s->set_wpc(s, 1);                        // 0 = disable , 1 = enable
      s->set_raw_gma(s, 1);                    // 0 = disable , 1 = enable
      s->set_lenc(s, 1);                       // 0 = disable , 1 = enable
      s->set_hmirror(s, 0);                    // 0 = disable , 1 = enable
      s->set_vflip(s, 0);                      // 0 = disable , 1 = enable
      s->set_dcw(s, 1);                        // 0 = disable , 1 = enable
      s->set_colorbar(s, 0);                   // 0 = disable , 1 = enable

  • 定义一个函数 takePicture() 来捕获图像并将其保存到 SD 卡中。

    void takePicture()
    {
      ESP_LOGI(cameraTag, "Taking picture...");
      camera_fb_t *pic = esp_camera_fb_get();

      if (pic)
      {
          saveJpegToSdcard(pic);
      }

      ESP_LOGI(cameraTag, "Picture taken! Its size was: %zu bytes", pic->len);

      esp_camera_fb_return(pic);
    }

  • 创建一个任务 cameraTakePicture_5_sec() 以每5秒连续拍摄一张照片。

    void cameraTakePicture_5_sec(void *pvParameters)
    {
        for (;;)
        {
            takePicture();
            vTaskDelay(5000 / portTICK_PERIOD_MS);
        }
    }

    void createCameraTask()
    {
        TaskHandle_t task;
        xTaskCreate(
            cameraTakePicture_5_sec,      /* Function that implements the task. */
            "cameraTakePicture_5_sec",    /* Text name for the task. */
            configMINIMAL_STACK_SIZE * 4, /* Stack size in words, or bytes. */
            NULL,                         /* Parameter passed into the task. */
            tskIDLE_PRIORITY,             /* Priority at which the task is created. */
            &task                         /* Used to pass out the created task's handle. */
        );
    }

代码结构：

  • 头文件（camera_config.h、camera_interface.h）和实现文件（camera_interface.c）。
  • camera_config.h 文件定义了摄像头配置参数。
  • camera_interface.h 文件声明了摄像头初始化和任务创建的函数。
  • camera_interface.c 文件实现了摄像头初始化、拍照和任务创建逻辑。

SdCard 组件​

  • SD 卡配置：
    定义了用于 SD 卡接口的 GPIO 引脚（MISO、MOSI、CLK、CS）。
#ifndef SDCARD_CONFIG_H
#define SDCARD_CONFIG_H

#define PIN_NUM_MISO  GPIO_NUM_8
#define PIN_NUM_MOSI  GPIO_NUM_9
#define PIN_NUM_CLK   GPIO_NUM_7
#define PIN_NUM_CS    GPIO_NUM_21

#endif //SDCARD_CONFIG_H
  • SD 卡接口： 声明函数 initialize_sdcard()、deinitialize_sdcard() 和 saveJpegToSdcard()。
#ifndef SDCARD_INTERFACE_H
#define SDCARD_INTERFACE_H

#include "esp_camera.h"

void initialize_sdcard(void);
void deinitialize_sdcard();
void saveJpegToSdcard(camera_fb_t *);

#endif //SDCARD_INTERFACE_H

  • SD卡实现：

    • 使用定义的配置初始化SD卡，并将SD卡挂载为FAT文件系统。
    sdmmc_card_t *card;
    sdmmc_host_t host = SDSPI_HOST_DEFAULT();
    const char mount_point[] = "/sd";

    void initialize_sdcard()
    {
        esp_err_t ret;

        // If format_if_mount_failed is set to true, SD card will be partitioned and
        // formatted in case when mounting fails.
        esp_vfs_fat_sdmmc_mount_config_t mount_config = {
    #ifdef FORMAT_IF_MOUNT_FAILED
            .format_if_mount_failed = true,
    #else
            .format_if_mount_failed = false,
    #endif // EXAMPLE_FORMAT_IF_MOUNT_FAILED
            .max_files = 5,
            .allocation_unit_size = 32 * 1024};

        ESP_LOGI(sdcardTag, "Initializing SD card");

        // Use settings defined above to initialize SD card and mount FAT filesystem.
        // Note: esp_vfs_fat_sdmmc/sdspi_mount is all-in-one convenience functions.
        // Please check its source code and implement error recovery when developing
        // production applications.
        ESP_LOGI(sdcardTag, "Using SPI peripheral");

        // By default, SD card frequency is initialized to SDMMC_FREQ_DEFAULT (20MHz)
        // For setting a specific frequency, use host.max_freq_khz (range 400kHz - 20MHz for SDSPI)
        spi_bus_config_t bus_cfg = {
            .mosi_io_num = PIN_NUM_MOSI,
            .miso_io_num = PIN_NUM_MISO,
            .sclk_io_num = PIN_NUM_CLK,
            .quadwp_io_num = -1,
            .quadhd_io_num = -1,
            .max_transfer_sz = host.max_freq_khz,
        };
        ret = spi_bus_initialize(host.slot, &bus_cfg, SDSPI_DEFAULT_DMA);
        if (ret != ESP_OK)
        {
            ESP_LOGE(sdcardTag, "Failed to initialize bus.");
            return;
        }

        // This initializes the slot without card detect (CD) and write protect (WP) signals.
        // Modify slot_config.gpio_cd and slot_config.gpio_wp if your board has these signals.
        sdspi_device_config_t slot_config = SDSPI_DEVICE_CONFIG_DEFAULT();
        slot_config.gpio_cs = PIN_NUM_CS;
        slot_config.host_id = host.slot;

        ESP_LOGI(sdcardTag, "Mounting filesystem");
        ret = esp_vfs_fat_sdspi_mount(mount_point, &host, &slot_config, &mount_config, &card);

        if (ret != ESP_OK)
        {
            if (ret == ESP_FAIL)
            {
                ESP_LOGE(sdcardTag, "Failed to mount filesystem. "
                                    "If you want the card to be formatted, set the FORMAT_IF_MOUNT_FAILED in sdcard_config.h");
            }
            else
            {
                ESP_LOGE(sdcardTag, "Failed to initialize the card (%s). "
                                    "Make sure SD card lines have pull-up resistors in place.",
                        esp_err_to_name(ret));
            }
            return;
        }
        ESP_LOGI(sdcardTag, "Filesystem mounted");

        // Card has been initialized, print its properties
        sdmmc_card_print_info(stdout, card);

        // Format FATFS
    #ifdef FORMAT_SD_CARD
        ret = esp_vfs_fat_sdcard_format(mount_point, card);
        if (ret != ESP_OK)
        {
            ESP_LOGE(sdcardTag, "Failed to format FATFS (%s)", esp_err_to_name(ret));
            return;
        }

        if (stat(file_foo, &st) == 0)
        {
            ESP_LOGI(sdcardTag, "file still exists");
            return;
        }
        else
        {
            ESP_LOGI(sdcardTag, "file doesnt exist, format done");
        }
    #endif // CONFIG_EXAMPLE_FORMAT_SD_CARD
    }
    • 提供将 JPEG 图像保存到 SD 卡的功能。
    uint16_t lastKnownFile = 0;

    void saveJpegToSdcard(camera_fb_t *captureImage)
    {
      // Find the next available filename
      char filename[32];

      sprintf(filename, "%s/%u_img.jpg", mount_point, lastKnownFile++);

      // Create the file and write the JPEG data
      FILE *fp = fopen(filename, "wb");
      if (fp != NULL)
      {
          fwrite(captureImage->buf, 1, captureImage->len, fp);
          fclose(fp);
          ESP_LOGI(sdcardTag, "JPEG saved as %s", filename);
      }
      else
      {
          ESP_LOGE(sdcardTag, "Failed to create file: %s", filename);
      }
    }

组件结构：

  • 头文件（sdcard_config.h、sdcard_interface.h）和实现文件（sdcard_interface.c）。
  • sdcard_config.h 文件定义了 SD 卡配置参数。
  • sdcard_interface.h 文件声明了 SD 卡初始化、去初始化和图像保存的函数。
  • sdcard_interface.c 文件实现了 SD 卡初始化、去初始化和图像保存逻辑。

主函数​

// main.c
#include <stdio.h>
#include "camera_interface.h"
#include "sdcard_interface.h"

void initialize_drivers()
{
    initialize_sdcard();
    initialize_camera();
}

void start_tasks()
{
    createCameraTask();
}

void app_main(void)
{
    initialize_drivers();
    start_tasks();
}
  • 包含摄像头和SD卡接口所需的头文件。
  • 使用提供的函数初始化SD卡和摄像头。
  • 启动摄像头任务以连续拍照

输出​

pir

UART输出​

I (1119) main_task: Calling app_main()
I (1123) sdcard: Initializing SD card
I (1127) sdcard: Using SPI peripheral
I (1132) sdcard: Mounting filesystem
I (1137) gpio: GPIO[21]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0
I (1146) sdspi_transaction: cmd=52, R1 response: command not supported
I (1195) sdspi_transaction: cmd=5, R1 response: command not supported
I (1219) sdcard: Filesystem mounted
Name: SD32G
Type: SDHC/SDXC
Speed: 20.00 MHz (limit: 20.00 MHz)
Size: 30448MB
CSD: ver=2, sector_size=512, capacity=62357504 read_bl_len=9
SSR: bus_width=1
I (1226) s3 ll_cam: DMA Channel=1
I (1230) cam_hal: cam init ok
I (1234) sccb: pin_sda 40 pin_scl 39
I (1238) sccb: sccb_i2c_port=1
I (1252) camera: Detected camera at address=0x30
I (1255) camera: Detected OV2640 camera
I (1255) camera: Camera PID=0x26 VER=0x42 MIDL=0x7f MIDH=0xa2
I (1344) cam_hal: buffer_size: 16384, half_buffer_size: 1024, node_buffer_size: 1024, node_cnt: 16, total_cnt: 375
I (1344) cam_hal: Allocating 384000 Byte frame buffer in PSRAM
I (1351) cam_hal: Allocating 384000 Byte frame buffer in PSRAM
I (1357) cam_hal: cam config ok
I (1361) ov2640: Set PLL: clk_2x: 0, clk_div: 0, pclk_auto: 0, pclk_div: 12
I (1453) camera: Camera configured successful
I (1487) main_task: Returned from app_main()
I (1487) camera: Taking picture...
I (1997) sdcard: JPEG saved as /sd/0_img.jpg
I (1997) camera: Picture taken! Its size was: 45764 bytes
I (6997) camera: Taking picture...
I (7348) sdcard: JPEG saved as /sd/1_img.jpg
I (7349) camera: Picture taken! Its size was: 51710 bytes
I (12349) camera: Taking picture...
I (12704) sdcard: JPEG saved as /sd/2_img.jpg
I (12705) camera: Picture taken! Its size was: 51853 bytes
I (17706) camera: Taking picture...
I (18054) sdcard: JPEG saved as /sd/3_img.jpg
I (18055) camera: Picture taken! Its size was: 51919 bytes
I (23055) camera: Taking picture...
I (23414) sdcard: JPEG saved as /sd/4_img.jpg
I (23414) camera: Picture taken! Its size was: 51809 bytes
I (28415) camera: Taking picture...
I (28768) sdcard: JPEG saved as /sd/5_img.jpg
I (28768) camera: Picture taken! Its size was: 51747 bytes
I (33771) camera: Taking picture...
I (34117) sdcard: JPEG saved as /sd/6_img.jpg
I (34117) camera: Picture taken! Its size was: 51968 bytes

输出图像​

pir

Arduino IDE 的 FreeRtos​

FreeRtos 可以用于基于 Arduino-IDE 的 XIAO-S3 构建。它类似于 ESP-IDF 可用，但它只在一个核心上运行，并且没有针对 ESP-IDF 进行优化。

硬件设置​

将 Xiao-S3 连接到 Grove 扩展板（OLED 显示屏和 RTC），并将 Grove - Arduino 温度、湿度、压力和气体传感器 - BME680 连接到 I2c 总线。

pir

软件设置​

安装 pcf8563、U8x8lib 和 bme680 库的 arduino 库。参考如何安装库来为 Arduino 安装库。

#include "time.h"
#include <WiFi.h>
#include <PCF8563.h>
#include <U8x8lib.h>
#include <Wire.h>
#include "seeed_bme680.h"

#define IIC_ADDR uint8_t(0x76)
Seeed_BME680 bme680(IIC_ADDR); /* IIC PROTOCOL */

// I2C communication library for the PCF8563 real-time clock
PCF8563 pcf;

// OLED display library
U8X8_SSD1306_128X64_NONAME_HW_I2C u8x8(/* clock=*/D4, /* data=*/D5, /* reset=*/U8X8_PIN_NONE);  // OLEDs without Reset of the Display

// WiFi network credentials
const char* ssid = "REPLACE_WITH_YOUR_SSID";
const char* password = "REPLACE_WITH_YOUR_PASSWORD";

// NTP server for time synchronization
const char* ntpServer = "pool.ntp.org";

// Timezone offset (adjust based on your location)
const long gmtOffset_sec = 5.5 * 60 * 60;  // Hours * Minutes * Seconds (here, GMT+5:30)
const int daylightOffset_sec = 0;          // No daylight saving time assumed

// Global variable to store current time information
static Time nowTime;

// Function prototypes for tasks
void printDateAndTime(void* pvParameters);
void updateTime(void* pvParameters);
void ledBlink2Hz(void* pvParameters);
void oledDisplayUpdate(void* pvParameters);
void taskBME680(void* pvParameters);

// Setup function (runs once at startup)
void setup() {

  Serial.begin(115200);  // Initialize serial communication for debugging

  // Set built-in LED pin as output for blinking
  pinMode(LED_BUILTIN, OUTPUT);

  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);  // Connect to WiFi network
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  while (!bme680.init()) {
    Serial.println("bme680 init failed ! can't find device!");
    delay(10000);
  }

  pcf.init();  // Initialize the PCF8563 real-time clock

  // Stop the clock before setting the time
  pcf.stopClock();

  // Configure time synchronization using NTP server
  configTime(gmtOffset_sec, daylightOffset_sec, ntpServer);
  static struct tm timeinfo;
  while (!getLocalTime(&timeinfo)) {
    Serial.println("no received time info ... Waiting ...");
  }

  // Set the time on the PCF8563 clock based on retrieved time
  pcf.setYear(timeinfo.tm_year);
  pcf.setMonth(timeinfo.tm_mon);
  pcf.setDay(timeinfo.tm_mday);
  pcf.setHour(timeinfo.tm_hour);
  pcf.setMinut(timeinfo.tm_min);
  pcf.setSecond(timeinfo.tm_sec);

  pcf.startClock();  // Start the clock after setting the time

  Serial.println("WiFi connected at " + WiFi.localIP());

  u8x8.begin();         // Initialize the OLED display
  u8x8.setFlipMode(1);  // Optionally rotate OLED display content

  // Create tasks for different functionalities
  xTaskCreate(
    updateTime,
    "Get LocalTime",
    configMINIMAL_STACK_SIZE * 2,
    (void*)1,
    tskIDLE_PRIORITY + 1,
    NULL);

  xTaskCreate(
    ledBlink2Hz,
    "Task 2",
    configMINIMAL_STACK_SIZE,
    (void*)1,
    tskIDLE_PRIORITY + 1,
    NULL);

  xTaskCreate(
    oledDisplayUpdate,
    "OLED Display Task",
    configMINIMAL_STACK_SIZE * 2,
    (void*)1,
    tskIDLE_PRIORITY,
    NULL);

  xTaskCreate(
    printDateAndTime,
    "Print Uart",
    configMINIMAL_STACK_SIZE * 2,
    (void*)1,
    tskIDLE_PRIORITY,
    NULL);

  xTaskCreate(
    taskBME680,
    "BME680 Sensor Poll",
    configMINIMAL_STACK_SIZE * 2,
    (void*)1,
    tskIDLE_PRIORITY + 1,
    NULL);
}

// Loop function (doesn't do anything in this case, tasks handle everything)
void loop() {
  // Nothing to do here, all work is done in the tasks
}

// Function that will run as a task: Prints current date and time to serial port
void printDateAndTime(void* pvParameters) {
  for (;;) {
    // Print current time in formatted string (DD/MM/YY\tHH:MM:SS) to serial port
    Serial.printf("%02d/%02d/%02d\t%02d:%02d:%02d\n",
                  nowTime.day, nowTime.month + 1, nowTime.year % 100,
                  nowTime.hour, nowTime.minute, nowTime.second);
    // Delay for 1 second before reading time again
    vTaskDelay(1000 / portTICK_PERIOD_MS);
  }
}

// Function that will run as a task: Reads current time from PCF8563 clock
void updateTime(void* pvParameters) {
  for (;;) {
    // Update the global `nowTime` variable with the current time from the PCF8563 clock
    nowTime = pcf.getTime();
    // Delay for 0.5 second before reading time again (can be adjusted for desired update frequency)
    vTaskDelay(500 / portTICK_PERIOD_MS);
  }
}

// Function that will run as a task: Blinks the built-in LED at 2Hz
void ledBlink2Hz(void* pvParameters) {
  bool state = true;  // Initial state for LED (on or off)
  for (;;) {
    // Set LED state (HIGH for on, LOW for off)
    digitalWrite(LED_BUILTIN, (state ? HIGH : LOW));
    // Delay for 0.5 second to create a 2Hz blinking frequency (one cycle on/off)
    vTaskDelay(500 / portTICK_PERIOD_MS);
    // Toggle LED state for the next cycle
    state = !state;
  }
}

// Function that will run as a task: Updates OLED display with date and time
void oledDisplayUpdate(void* pvParameters) {
  for (;;) {

    // Set font for the first line (date)
    u8x8.setFont(u8x8_font_chroma48medium8_r);

    // Set cursor position for the first line (centered)
    u8x8.setCursor(0, 0);

    char buffer1[12];  // Buffer to hold formatted date string
    std::snprintf(buffer1, sizeof(buffer1), "%02d/%02d/%02d",
                  nowTime.day, nowTime.month + 1, nowTime.year % 100);
    u8x8.print(buffer1);

    // Format time string (HH:MM:SS) into buffer2 using std::snprintf
    std::snprintf(buffer1, sizeof(buffer1), "%02d:%02d:%02d",
                  nowTime.hour, nowTime.minute, nowTime.second);
    // Print formatted time string to OLED display
    u8x8.print(buffer1);

    // Adjust cursor position for the second line (below the first line)
    u8x8.setCursor(0, 10);

    char buffer2[20];  // Buffer to hold formatted sensor data

    std::snprintf(buffer2, sizeof(buffer2), "T: %.1f°C", bme680.sensor_result_value.temperature);
    u8x8.print(buffer2);
    u8x8.setCursor(0, 20);

    std::snprintf(buffer2, sizeof(buffer2), "P: %.1fkPa", bme680.sensor_result_value.pressure / 1000.0);
    u8x8.print(buffer2);

    u8x8.setCursor(0, 30);

    std::snprintf(buffer2, sizeof(buffer2), "H: %.1f%%", bme680.sensor_result_value.humidity);
    u8x8.print(buffer2);

    // std::snprintf(buffer2, sizeof(buffer2), "G: %.1f Kohms", bme680.sensor_result_value.gas / 1000.0);
    // u8x8.print(buffer2);

    vTaskDelay(100 / portTICK_PERIOD_MS);  // Update every 0.1 seconds (adjust as needed)
  }
}

void taskBME680(void* pvParameters) {
  for (;;) {
    if (bme680.read_sensor_data()) {
      Serial.println("Failed to perform reading :(");
    } else {
      Serial.print("T: ");
      Serial.print(bme680.sensor_result_value.temperature, 2);
      Serial.print(" C  P: ");
      Serial.print(bme680.sensor_result_value.pressure / 1000.0, 2);
      Serial.print(" KPa  H: ");
      Serial.print(bme680.sensor_result_value.humidity, 2);
      Serial.print(" %  G: ");
      Serial.print(bme680.sensor_result_value.gas / 1000.0, 2);
      Serial.println(" Kohms");
    }

    vTaskDelay(1000 / portTICK_PERIOD_MS);
  }
}

输出​

pir

串口监视器输出​

09/09/24 03:17:20
T: 29.01 C  P: 90.86 KPa  H: 63.41 %  G: 47.41 Kohms
09/09/24 03:17:21
T: 29.03 C  P: 90.86 KPa  H: 63.34 %  G: 47.85 Kohms

Arduino FreeRtos vs ESP-IDF FreeRtos​

FeatureArduino FreeRTOSESP-IDF FreeRTOS
抽象层更高级别的抽象，对初学者更容易更低级别的抽象，为有经验的用户提供更多控制
开发环境Arduino IDEESP-IDF 命令行工具
兼容性主要兼容基于 Arduino 的开发板兼容更广泛的 ESP32 和 ESP32-S2 开发板
功能基本的 RTOS 功能，任务创建、调度、同步全面的 RTOS 功能，任务创建、调度、同步、事件组、队列、互斥锁、信号量
性能由于抽象层的存在，性能通常较低由于直接访问硬件和 RTOS API，性能更高
定制化定制化选项有限通过配置文件和 API 提供广泛的定制化选项
学习曲线对初学者来说更容易学习对于不熟悉命令行工具和 C/C++ 的人来说学习曲线更陡峭
使用场景简单的物联网项目、原型开发复杂的物联网应用、实时系统、定制硬件

故障排除​

在硬件连接、软件调试或上传过程中可能会遇到一些问题。

技术支持与产品讨论​

感谢您选择我们的产品！我们在这里为您提供不同的支持，以确保您使用我们产品的体验尽可能顺畅。我们提供多种沟通渠道，以满足不同的偏好和需求。

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