ESP32-C3入门教程基础篇⑧——WS2812 全彩RGB LED灯带

左手的ㄟ右手 2022-09-11 09:22 1007阅读 0赞

### 文章目录 ###

*  一、前言
 *  二、快速运行
 *  三、运行效果
 *  四、硬件说明
 *  五、RMT简介
 *  六、例程说明
 *  七、优化与效果
 *  八、相关函数说明
 *   *  8.1 rmt 相关
     *  8.2 led strip 相关
 *  九、参考

# 一、前言 #

> 本文基于VS Code IDE进行编程、编译、下载、运行等操作  
> 基础知识点请查阅：[ESP32-C3入门教程 基础篇①——基于VS Code构建Hello World][ESP32-C3_ _VS Code_Hello World]

# 二、快速运行 #

*  示例项目中，选择`peripherals`—>`rmt`—>`led_strip`
 *  `menuconfig`配置`ESP32C3-Specific`—>`Rec 0`
 *  芯片选择`ESP32-C3(Built-in USB JTAG)`
 *  快速运行`ESP-IDF Build, Flash and Monitor`（左下角）

# 三、运行效果 #

ESP32-C3入门教程 基础篇⑧——WS2812 全彩RGB LED灯带2

# 四、硬件说明 #

从硬件原理图中可以看出来

*  `RGB LED`是通过`GPIO8`来控制
 *  而`RGB LED`是`SK68XXMINI-HS`
 *  大部分人对`SK68XXMINI`不熟悉，但是对`WS2812`熟悉
 *  查一下资料就晓得，`SK68XXMINI`和`WS2812`其实是一个东西，控制原理是一样的
 *  [SK68XXMINI资料][SK68XXMINI]
 *  [WS2812资料][WS2812]，[WS2812资料2][WS2812_2]  
    ![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5bCP5bq35biI5YWE_size_20_color_FFFFFF_t_70_g_se_x_16]  
    ![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5bCP5bq35biI5YWE_size_20_color_FFFFFF_t_70_g_se_x_16 1]

![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5bCP5bq35biI5YWE_size_20_color_FFFFFF_t_70_g_se_x_16 2]

![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5bCP5bq35biI5YWE_size_20_color_FFFFFF_t_70_g_se_x_16 3]

# 五、RMT简介 #

> RMT 是 Remote Control 的简称。由于RMT模块的灵活性，驱动器还可用于生成或接收许多其他类型的信号。

> [WS2812][WS2812 1]是一个数字RGB LED，其定义的协议数据格式与RMT外围设备中的协议数据格式兼容。

*  RMT发送  
    ![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5bCP5bq35biI5YWE_size_20_color_FFFFFF_t_70_g_se_x_16 4]
 *  RMT接收  
    ![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5bCP5bq35biI5YWE_size_20_color_FFFFFF_t_70_g_se_x_16 5]

# 六、例程说明 #

*  RMT配置`rmt_config`
    
     *  `rmt_mode = RMT_MODE_TX`输出模式
     *  `channel`通道号
     *  `gpio_num`GPIO口
     *  其他
 *  RMT驱动安装`rmt_driver_install`
    
     *  `channel`通道号
     *  `rx_buf_size = 0`接收缓存大小
     *  `intr_alloc_flags = 0`
 *  led\_strip配置`LED_STRIP_DEFAULT_CONFIG`
    
     *  `max_leds`最大LED个数
     *  `dev`设备手柄，即RMT通道号的地址
 *  led\_strip实例化`led_strip_new_rmt_ws2812`
    
     *  `led_strip_config_t` led\_strip配置参数
 *  led\_strip实例化后有多个方法
    
     *  `esp_err_t (*set_pixel)(led_strip_t *strip, uint32_t index, uint32_t red, uint32_t green, uint32_t blue);`为特定像素设置RGB
     *  `esp_err_t (*refresh)(led_strip_t *strip, uint32_t timeout_ms);`刷新LEDs颜色
     *  `esp_err_t (*clear)(led_strip_t *strip, uint32_t timeout_ms);`关闭所有LEDs
     *  `esp_err_t (*del)(led_strip_t *strip);`释放LEDs所有资源
 *  while循环
    
     *  hue从0到360的阶梯递增
     *  hue转rgb
     *  `strip->set_pixel(strip, j, red, green, blue)`设置RGB进去到第j个LED
     *  `strip->refresh(strip, 100)`刷新LED的颜色
     *  延时
     *  `strip->clear(strip, 50);`关闭所有LEDs
     *  延时
     *  循环……

void app_main(void)
    { 
        uint32_t red = 0;
        uint32_t green = 0;
        uint32_t blue = 0;
        uint16_t hue = 0;
        uint16_t start_rgb = 0;
    
        rmt_config_t config = RMT_DEFAULT_CONFIG_TX(CONFIG_EXAMPLE_RMT_TX_GPIO, RMT_TX_CHANNEL);
        // set counter clock to 40MHz
        config.clk_div = 2;
    
        ESP_ERROR_CHECK(rmt_config(&config));
        ESP_ERROR_CHECK(rmt_driver_install(config.channel, 0, 0));
    
        // install ws2812 driver
        led_strip_config_t strip_config = LED_STRIP_DEFAULT_CONFIG(CONFIG_EXAMPLE_STRIP_LED_NUMBER, (led_strip_dev_t)config.channel);
        led_strip_t *strip = led_strip_new_rmt_ws2812(&strip_config);
        if (!strip) { 
            ESP_LOGE(TAG, "install WS2812 driver failed");
        }
        // Clear LED strip (turn off all LEDs)
        ESP_ERROR_CHECK(strip->clear(strip, 100));
        // Show simple rainbow chasing pattern
        ESP_LOGI(TAG, "LED Rainbow Chase Start");
        while (true) { 
            for (int i = 0; i < 3; i++) { 
                for (int j = i; j < CONFIG_EXAMPLE_STRIP_LED_NUMBER; j += 3) { 
                    // Build RGB values
                    hue = j * 360 / CONFIG_EXAMPLE_STRIP_LED_NUMBER + start_rgb;
                    led_strip_hsv2rgb(hue, 100, 100, &red, &green, &blue);
                    // Write RGB values to strip driver
                    ESP_ERROR_CHECK(strip->set_pixel(strip, j, red, green, blue));
                }
                // Flush RGB values to LEDs
                ESP_ERROR_CHECK(strip->refresh(strip, 100));
                vTaskDelay(pdMS_TO_TICKS(EXAMPLE_CHASE_SPEED_MS));
                strip->clear(strip, 50);
                vTaskDelay(pdMS_TO_TICKS(EXAMPLE_CHASE_SPEED_MS));
            }
            start_rgb += 60;
        }
    }

# 七、优化与效果 #

我感觉这个效果在我这个开发板上面效果不咋地，所以我做了如下优化

*  首先，RMT TX的GPIO在开发板上面是GPIO8，所以，`#define EXAMPLE_RMT_TX_GPIO 8`
 *  其次，RGB LED我就一个，所以，`#define EXAMPLE_STRIP_LED_NUMBER 1`
 *  最后，hue递增，再转rgb的方式，太骚了，不适合我。我直接红绿蓝RGB三种颜色每秒流转即可

改动后效果如下：

ESP32-C3入门教程 基础篇⑧——WS2812 全彩RGB LED灯带3

改动代码如下：

#include "sdkconfig.h"
    #include "freertos/FreeRTOS.h"
    #include "freertos/task.h"
    #include "esp_log.h"
    #include "driver/rmt.h"
    #include "led_strip.h"
    
    static const char *TAG = "example";
    
    #define RMT_TX_CHANNEL RMT_CHANNEL_0
    
    #define EXAMPLE_CHASE_SPEED_MS (1000)
    
    #define EXAMPLE_RMT_TX_GPIO 8
    
    #define EXAMPLE_STRIP_LED_NUMBER 1
    
    void app_main(void)
    { 
        rmt_config_t config = RMT_DEFAULT_CONFIG_TX(EXAMPLE_RMT_TX_GPIO, RMT_TX_CHANNEL);
        // set counter clock to 40MHz
        config.clk_div = 2;
    
        ESP_ERROR_CHECK(rmt_config(&config));
        ESP_ERROR_CHECK(rmt_driver_install(config.channel, 0, 0));
    
        // install ws2812 driver
        led_strip_config_t strip_config = LED_STRIP_DEFAULT_CONFIG(EXAMPLE_STRIP_LED_NUMBER, (led_strip_dev_t)config.channel);
        led_strip_t *strip = led_strip_new_rmt_ws2812(&strip_config);
        if (!strip) { 
            ESP_LOGE(TAG, "install WS2812 driver failed");
        }
        // Clear LED strip (turn off all LEDs)
        ESP_ERROR_CHECK(strip->clear(strip, 100));
        // Show simple rainbow chasing pattern
        ESP_LOGI(TAG, "LED Rainbow Chase Start");
        while (true) {         
            strip->set_pixel(strip, 0, 255, 0, 0);
            strip->refresh(strip, 50);
            vTaskDelay(pdMS_TO_TICKS(EXAMPLE_CHASE_SPEED_MS));
    
            strip->set_pixel(strip, 0, 0, 255, 0);
            strip->refresh(strip, 50);
            vTaskDelay(pdMS_TO_TICKS(EXAMPLE_CHASE_SPEED_MS));
    
            
            strip->set_pixel(strip, 0, 0, 0, 255);
            strip->refresh(strip, 50);
            vTaskDelay(pdMS_TO_TICKS(EXAMPLE_CHASE_SPEED_MS));
        }
    }

# 八、相关函数说明 #

## 8.1 rmt 相关 ##

`\esp-idf\components\driver\include\driver\rmt.h`

/** * @brief Data struct of RMT configure parameters */
    typedef struct { 
        rmt_mode_t rmt_mode;   /*!< RMT mode: transmitter or receiver */
        rmt_channel_t channel; /*!< RMT channel */
        gpio_num_t gpio_num;   /*!< RMT GPIO number */
        uint8_t clk_div;       /*!< RMT channel counter divider */
        uint8_t mem_block_num; /*!< RMT memory block number */
        uint32_t flags;        /*!< RMT channel extra configurations, OR'd with RMT_CHANNEL_FLAGS_[*] */
        union { 
            rmt_tx_config_t tx_config; /*!< RMT TX parameter */
            rmt_rx_config_t rx_config; /*!< RMT RX parameter */
        };
    } rmt_config_t;
    
    /** * @brief Default configuration for Tx channel * */
    #define RMT_DEFAULT_CONFIG_TX(gpio, channel_id) \ { \ .rmt_mode = RMT_MODE_TX, \ .channel = channel_id, \ .gpio_num = gpio, \ .clk_div = 80, \ .mem_block_num = 1, \ .flags = 0, \ .tx_config = { \ .carrier_freq_hz = 38000, \ .carrier_level = RMT_CARRIER_LEVEL_HIGH, \ .idle_level = RMT_IDLE_LEVEL_LOW, \ .carrier_duty_percent = 33, \ .carrier_en = false, \ .loop_en = false, \ .idle_output_en = true, \ } \ }

`components\driver\rmt.c`

esp_err_t rmt_config(const rmt_config_t *rmt_param)
    
    esp_err_t rmt_driver_install(rmt_channel_t channel, size_t rx_buf_size, int intr_alloc_flags)

## 8.2 led strip 相关 ##

`\components\led_strip\include\led_strip.h`

/** * @brief LED Strip Configuration Type * */
    typedef struct { 
        uint32_t max_leds;   /*!< Maximum LEDs in a single strip */
        led_strip_dev_t dev; /*!< LED strip device (e.g. RMT channel, PWM channel, etc) */
    } led_strip_config_t;
    
    /** * @brief Declare of LED Strip Type * */
    struct led_strip_s { 
        /** * @brief Set RGB for a specific pixel * * @param strip: LED strip * @param index: index of pixel to set * @param red: red part of color * @param green: green part of color * @param blue: blue part of color * * @return * - ESP_OK: Set RGB for a specific pixel successfully * - ESP_ERR_INVALID_ARG: Set RGB for a specific pixel failed because of invalid parameters * - ESP_FAIL: Set RGB for a specific pixel failed because other error occurred */
        esp_err_t (*set_pixel)(led_strip_t *strip, uint32_t index, uint32_t red, uint32_t green, uint32_t blue);
    
        /** * @brief Refresh memory colors to LEDs * * @param strip: LED strip * @param timeout_ms: timeout value for refreshing task * * @return * - ESP_OK: Refresh successfully * - ESP_ERR_TIMEOUT: Refresh failed because of timeout * - ESP_FAIL: Refresh failed because some other error occurred * * @note: * After updating the LED colors in the memory, a following invocation of this API is needed to flush colors to strip. */
        esp_err_t (*refresh)(led_strip_t *strip, uint32_t timeout_ms);
    
        /** * @brief Clear LED strip (turn off all LEDs) * * @param strip: LED strip * @param timeout_ms: timeout value for clearing task * * @return * - ESP_OK: Clear LEDs successfully * - ESP_ERR_TIMEOUT: Clear LEDs failed because of timeout * - ESP_FAIL: Clear LEDs failed because some other error occurred */
        esp_err_t (*clear)(led_strip_t *strip, uint32_t timeout_ms);
    
        /** * @brief Free LED strip resources * * @param strip: LED strip * * @return * - ESP_OK: Free resources successfully * - ESP_FAIL: Free resources failed because error occurred */
        esp_err_t (*del)(led_strip_t *strip);
    };

# 九、参考 #

[Remote Control (RMT) - ESP32-C2 - —— ESP-IDF编程指南][Remote Control _RMT_ - ESP32-C2 - _ ESP-IDF]

***觉得好，就一键三连呗（点赞+收藏+关注）***

[ESP32-C3_ _VS Code_Hello World]: https://blog.csdn.net/kangweijian/article/details/120284617
[SK68XXMINI]: https://www.docin.com/p-2320072812.html
[WS2812]: https://wenku.baidu.com/view/0925958fba68a98271fe910ef12d2af90342a80e.html
[WS2812_2]: https://atta.szlcsc.com/upload/public/pdf/source/20200615/C114586_26EB6813EC9F2A3F6C7FBB2AD75DE01F.pdf
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[WS2812 1]: http://www.world-semi.com/Certifications/WS2812B.html
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[Remote Control _RMT_ - ESP32-C2 - _ ESP-IDF]: https://docs.espressif.com/projects/esp-idf/zh_CN/latest/esp32c3/api-reference/peripherals/rmt.html?highlight=rmt#