feat(display): Remove display task to instead have lvgl handle it directly (#400)

* feat: Have LVGL use freertos timing functions

* refactor: Applied change to user components

* fix: Set correct LVGL delay callback

* fix: Fixed component examples

Author: abrondijk

components/display/include/display.hpp

@@ -80,12 +80,6 @@ template <typename Pixel> class Display : public BaseComponent {
         nullptr}; /**< Optional function used to configure display with new rotation setting. */
     DisplayRotation rotation{
         DisplayRotation::LANDSCAPE}; /**< Default / Initial rotation of the display. */
-    Task::BaseConfig task_config{.name = "Display",
-                                 .stack_size_bytes = 4096,
-                                 .priority = 20,
-                                 .core_id = 0}; /**< Task configuration. */
-    std::chrono::duration<float> update_period{
-        0.01}; /**< How frequently to run the update function. */
   };
 
   /**
@@ -148,11 +142,9 @@ template <typename Pixel> class Display : public BaseComponent {
       , height_(lvgl_conf.height)
       , display_buffer_px_size_(mem_conf.pixel_buffer_size)
       , vram_0_(mem_conf.vram0)
-      , vram_1_(mem_conf.vram1)
-      , update_period_(lvgl_conf.update_period) {
+      , vram_1_(mem_conf.vram1) {
     init_backlight(lcd_config.backlight_pin, lcd_config.backlight_on_value);
-    init_gfx(lvgl_conf.flush_callback, lvgl_conf.rotation_callback, lvgl_conf.rotation,
-             lvgl_conf.task_config);
+    init_gfx(lvgl_conf.flush_callback, lvgl_conf.rotation_callback, lvgl_conf.rotation);
     set_brightness(1.0);
   }
 
@@ -170,12 +162,10 @@ template <typename Pixel> class Display : public BaseComponent {
       : BaseComponent("Display", log_level)
       , width_(lvgl_conf.width)
       , height_(lvgl_conf.height)
-      , display_buffer_px_size_(mem_conf.pixel_buffer_size)
-      , update_period_(lvgl_conf.update_period) {
+      , display_buffer_px_size_(mem_conf.pixel_buffer_size) {
     init_memory(mem_conf.double_buffered, mem_conf.allocation_flags);
     init_backlight(lcd_config.backlight_pin, lcd_config.backlight_on_value);
-    init_gfx(lvgl_conf.flush_callback, lvgl_conf.rotation_callback, lvgl_conf.rotation,
-             lvgl_conf.task_config);
+    init_gfx(lvgl_conf.flush_callback, lvgl_conf.rotation_callback, lvgl_conf.rotation);
     set_brightness(1.0);
   }
 
@@ -196,11 +186,9 @@ template <typename Pixel> class Display : public BaseComponent {
       , display_buffer_px_size_(mem_conf.pixel_buffer_size)
       , vram_0_(mem_conf.vram0)
       , vram_1_(mem_conf.vram1)
-      , update_period_(lvgl_conf.update_period)
       , set_brightness_(oled_config.set_brightness_callback)
       , get_brightness_(oled_config.get_brightness_callback) {
-    init_gfx(lvgl_conf.flush_callback, lvgl_conf.rotation_callback, lvgl_conf.rotation,
-             lvgl_conf.task_config);
+    init_gfx(lvgl_conf.flush_callback, lvgl_conf.rotation_callback, lvgl_conf.rotation);
     set_brightness(1.0);
   }
 
@@ -219,20 +207,17 @@ template <typename Pixel> class Display : public BaseComponent {
       , width_(lvgl_conf.width)
       , height_(lvgl_conf.height)
       , display_buffer_px_size_(mem_conf.pixel_buffer_size)
-      , update_period_(lvgl_conf.update_period)
       , set_brightness_(oled_config.set_brightness_callback)
       , get_brightness_(oled_config.get_brightness_callback) {
     init_memory(mem_conf.double_buffered, mem_conf.allocation_flags);
-    init_gfx(lvgl_conf.flush_callback, lvgl_conf.rotation_callback, lvgl_conf.rotation,
-             lvgl_conf.task_config);
+    init_gfx(lvgl_conf.flush_callback, lvgl_conf.rotation_callback, lvgl_conf.rotation);
     set_brightness(1.0);
   }
 
   /**
    * @brief Stops the upate task and frees the display buffer memory.
    */
   ~Display() {
-    task_->stop();
     if (created_vram_) {
       free(vram_0_);
       free(vram_1_);
@@ -282,18 +267,6 @@ template <typename Pixel> class Display : public BaseComponent {
     return 0.0f;
   }
 
-  /**
-   * @brief Pause the display update task, to prevent LVGL from writing to the
-   *        display.
-   */
-  void pause() { paused_ = true; }
-
-  /**
-   * @brief Resume the display update task, to allow LVGL to write to the
-   *        display.
-   */
-  void resume() { paused_ = false; }
-
   /**
    * @brief Force a redraw / refresh of the display.
    *
@@ -395,10 +368,9 @@ template <typename Pixel> class Display : public BaseComponent {
    * @param flush_callback Callback used to flush color data to the display.
    * @param rotation_callback function to call in the event handler on rotation change.
    * @param rotation Default / initial rotation of the display.
-   * @param task_config Configuration for the task that runs the lvgl tick
    */
   void init_gfx(const flush_fn flush_callback, const rotation_fn rotation_callback,
-                DisplayRotation rotation, const Task::BaseConfig &task_config) {
+                DisplayRotation rotation) {
     // save the callbacks
     if (flush_callback == nullptr) {
       logger_.error("No flush callback provided, cannot initialize display!");
@@ -413,6 +385,10 @@ template <typename Pixel> class Display : public BaseComponent {
 
     lv_init();
 
+    lv_tick_set_cb(xTaskGetTickCount);
+
+    lv_delay_set_cb(vTaskDelay_wrapper);
+
     display_ = lv_display_create(width_, height_);
     // store a pointer to this object in the display user data, so that we can
     // access it in the flush callback
@@ -429,14 +405,6 @@ template <typename Pixel> class Display : public BaseComponent {
 
     // Setting as default display, allows the use of lv_disp_get_default()
     lv_display_set_default(display_);
-
-    // Now start the task for the ui management
-    using namespace std::placeholders;
-    task_ = Task::make_unique({
-        .callback = std::bind(&Display::update, this, _1, _2, _3),
-        .task_config = task_config,
-    });
-    task_->start();
   }
 
   /**
@@ -479,35 +447,12 @@ template <typename Pixel> class Display : public BaseComponent {
   }
 
   /**
-   * @brief Flush the data to the display, called within the task_.
-   *
-   *   This task should always be high priority, so that it is higher than
-   *   than the task running lv_task_handler(). For more info, see
-   *   https://docs.lvgl.io/latest/en/html/porting/tick.html
+   * @brief Wrapper around vTaskDelay, to pass to LVGL.
+   *        If not, LVGL will do random math as to delay the task instead.
+   * @param ms The number of milliseconds to delay.
    */
-  bool update(std::mutex &m, std::condition_variable &cv, bool &task_notified) {
-    auto now = std::chrono::high_resolution_clock::now();
-    static auto prev = now;
-    if (!paused_) {
-      int elapsed_ms = std::chrono::duration_cast<std::chrono::milliseconds>(now - prev).count();
-      // we shouldn't stop, update the display
-      lv_tick_inc(elapsed_ms);
-    }
-    // update previous timestamp
-    prev = now;
-    // delay
-    {
-      using namespace std::chrono_literals;
-      std::unique_lock<std::mutex> lk(m);
-      cv.wait_for(lk, update_period_, [&task_notified] { return task_notified; });
-      task_notified = false;
-    }
-    // don't want to stop the task
-    return false;
-  }
+  static void vTaskDelay_wrapper(const uint32_t ms) { vTaskDelay(pdMS_TO_TICKS(ms)); }
 
-  std::atomic<bool> paused_{false};
-  std::unique_ptr<Task> task_;
   size_t width_;
   size_t height_;
   flush_fn flush_callback_{nullptr};
@@ -518,7 +463,6 @@ template <typename Pixel> class Display : public BaseComponent {
   bool created_vram_{false};
   std::vector<Led::ChannelConfig> led_channel_configs_;
   std::unique_ptr<Led> backlight_{nullptr};
-  std::chrono::duration<float> update_period_;
   lv_display_t *display_;
   set_brightness_fn set_brightness_{nullptr};
   get_brightness_fn get_brightness_{nullptr};

components/esp-box/example/main/esp_box_example.cpp

@@ -66,14 +66,8 @@ extern "C" void app_main(void) {
   }
   // set the pixel buffer to be 50 lines high
   static constexpr size_t pixel_buffer_size = box.lcd_width() * 50;
-  espp::Task::BaseConfig display_task_config = {
-      .name = "Display",
-      .stack_size_bytes = 6 * 1024,
-      .priority = 10,
-      .core_id = 0,
-  };
   // initialize the LVGL display for the esp-box
-  if (!box.initialize_display(pixel_buffer_size, display_task_config)) {
+  if (!box.initialize_display(pixel_buffer_size)) {
     logger.error("Failed to initialize display!");
     return;
   }

components/esp-box/include/esp-box.hpp

@@ -145,16 +145,9 @@ class EspBox : public BaseComponent {
 
   /// Initialize the display (lvgl display driver)
   /// \param pixel_buffer_size The size of the pixel buffer
-  /// \param task_config The task configuration for the display task
-  /// \param update_period_ms The update period of the display task
   /// \return true if the display was successfully initialized, false otherwise
   /// \note This will also allocate two full frame buffers in the SPIRAM
-  bool initialize_display(size_t pixel_buffer_size,
-                          const espp::Task::BaseConfig &task_config = {.name = "Display",
-                                                                       .stack_size_bytes = 4096,
-                                                                       .priority = 10,
-                                                                       .core_id = 0},
-                          int update_period_ms = 16);
+  bool initialize_display(size_t pixel_buffer_size);
 
   /// Get the width of the LCD in pixels
   /// \return The width of the LCD in pixels

components/esp-box/src/video.cpp

@@ -86,8 +86,7 @@ bool EspBox::initialize_lcd() {
   return true;
 }
 
-bool EspBox::initialize_display(size_t pixel_buffer_size, const espp::Task::BaseConfig &task_config,
-                                int update_period_ms) {
+bool EspBox::initialize_display(size_t pixel_buffer_size) {
   if (!lcd_handle_) {
     logger_.error(
         "LCD not initialized, you must call initialize_lcd() before initialize_display()!");
@@ -104,9 +103,7 @@ bool EspBox::initialize_display(size_t pixel_buffer_size, const espp::Task::Base
                                  .height = lcd_height_,
                                  .flush_callback = DisplayDriver::flush,
                                  .rotation_callback = DisplayDriver::rotate,
-                                 .rotation = rotation,
-                                 .task_config = task_config,
-                                 .update_period = 1ms * update_period_ms},
+                                 .rotation = rotation},
       Display<Pixel>::LcdConfig{.backlight_pin = backlight_io,
                                 .backlight_on_value = backlight_value},
       Display<Pixel>::DynamicMemoryConfig{

components/matouch-rotary-display/include/matouch-rotary-display.hpp

@@ -147,16 +147,9 @@ class MatouchRotaryDisplay : public BaseComponent {
 
   /// Initialize the display (lvgl display driver)
   /// \param pixel_buffer_size The size of the pixel buffer
-  /// \param task_config The task configuration for the display task
-  /// \param update_period_ms The update period of the display task
   /// \return true if the display was successfully initialized, false otherwise
   /// \note This will also allocate two full frame buffers in the SPIRAM
-  bool initialize_display(size_t pixel_buffer_size,
-                          const espp::Task::BaseConfig &task_config = {.name = "Display",
-                                                                       .stack_size_bytes = 4096,
-                                                                       .priority = 10,
-                                                                       .core_id = 0},
-                          int update_period_ms = 16);
+  bool initialize_display(size_t pixel_buffer_size);
 
   /// Get the width of the LCD in pixels
   /// \return The width of the LCD in pixels

components/matouch-rotary-display/src/matouch-rotary-display.cpp

@@ -283,9 +283,7 @@ bool MatouchRotaryDisplay::initialize_lcd() {
   return true;
 }
 
-bool MatouchRotaryDisplay::initialize_display(size_t pixel_buffer_size,
-                                              const espp::Task::BaseConfig &task_config,
-                                              int update_period_ms) {
+bool MatouchRotaryDisplay::initialize_display(size_t pixel_buffer_size) {
   if (!lcd_handle_) {
     logger_.error(
         "LCD not initialized, you must call initialize_lcd() before initialize_display()!");
@@ -302,9 +300,7 @@ bool MatouchRotaryDisplay::initialize_display(size_t pixel_buffer_size,
                                  .height = lcd_height_,
                                  .flush_callback = DisplayDriver::flush,
                                  .rotation_callback = DisplayDriver::rotate,
-                                 .rotation = rotation,
-                                 .task_config = task_config,
-                                 .update_period = 1ms * update_period_ms},
+                                 .rotation = rotation},
       Display<Pixel>::LcdConfig{.backlight_pin = backlight_io,
                                 .backlight_on_value = backlight_value},
       Display<Pixel>::DynamicMemoryConfig{

components/seeed-studio-round-display/example/main/seeed_studio_round_display_example.cpp

@@ -61,14 +61,8 @@ extern "C" void app_main(void) {
   }
   // set the pixel buffer to be 50 lines high
   static constexpr size_t pixel_buffer_size = round_display.lcd_width() * 50;
-  espp::Task::BaseConfig display_task_config = {
-      .name = "Display",
-      .stack_size_bytes = 6 * 1024,
-      .priority = 10,
-      .core_id = 0,
-  };
   // initialize the LVGL display for the seeed-studio-round-display
-  if (!round_display.initialize_display(pixel_buffer_size, display_task_config)) {
+  if (!round_display.initialize_display(pixel_buffer_size)) {
     logger.error("Failed to initialize display!");
     return;
   }

components/seeed-studio-round-display/include/seeed-studio-round-display.hpp

@@ -164,16 +164,9 @@ class SsRoundDisplay : public espp::BaseComponent {
 
   /// Initialize the display (lvgl display driver)
   /// \param pixel_buffer_size The size of the pixel buffer
-  /// \param task_config The task configuration for the display task
-  /// \param update_period_ms The update period of the display task
   /// \return true if the display was successfully initialized, false otherwise
   /// \note This will also allocate two full frame buffers in the SPIRAM
-  bool initialize_display(size_t pixel_buffer_size,
-                          const espp::Task::BaseConfig &task_config = {.name = "Display",
-                                                                       .stack_size_bytes = 4096,
-                                                                       .priority = 10,
-                                                                       .core_id = 0},
-                          int update_period_ms = 16);
+  bool initialize_display(size_t pixel_buffer_size);
 
   /// Get the width of the LCD in pixels
   /// \return The width of the LCD in pixels

components/seeed-studio-round-display/src/seeed-studio-round-display.cpp

@@ -243,9 +243,7 @@ bool SsRoundDisplay::initialize_lcd() {
   return true;
 }
 
-bool SsRoundDisplay::initialize_display(size_t pixel_buffer_size,
-                                        const espp::Task::BaseConfig &task_config,
-                                        int update_period_ms) {
+bool SsRoundDisplay::initialize_display(size_t pixel_buffer_size) {
   if (!lcd_handle_) {
     logger_.error(
         "LCD not initialized, you must call initialize_lcd() before initialize_display()!");
@@ -262,9 +260,7 @@ bool SsRoundDisplay::initialize_display(size_t pixel_buffer_size,
                                  .height = lcd_height_,
                                  .flush_callback = DisplayDriver::flush,
                                  .rotation_callback = DisplayDriver::rotate,
-                                 .rotation = rotation,
-                                 .task_config = task_config,
-                                 .update_period = 1ms * update_period_ms},
+                                 .rotation = rotation},
       Display<Pixel>::LcdConfig{.backlight_pin = pin_config_.lcd_backlight,
                                 .backlight_on_value = backlight_value},
       Display<Pixel>::DynamicMemoryConfig{

components/t-deck/include/t-deck.hpp

@@ -239,16 +239,9 @@ class TDeck : public BaseComponent {
 
   /// Initialize the display (lvgl display driver)
   /// \param pixel_buffer_size The size of the pixel buffer
-  /// \param task_config The task configuration for the display task
-  /// \param update_period_ms The update period of the display task
   /// \return true if the display was successfully initialized, false otherwise
   /// \note This will also allocate two full frame buffers in the SPIRAM
-  bool initialize_display(size_t pixel_buffer_size,
-                          const espp::Task::BaseConfig &task_config = {.name = "Display",
-                                                                       .stack_size_bytes = 4096,
-                                                                       .priority = 10,
-                                                                       .core_id = 0},
-                          int update_period_ms = 16);
+  bool initialize_display(size_t pixel_buffer_size);
 
   /// Get the width of the LCD in pixels
   /// \return The width of the LCD in pixels