More cleanup.

esp/cpp/07_lcd-panel/main/display.cpp

@@ -13,7 +13,8 @@
 _lock_t Display::ScopedLock::lv_lock_;
 
 Display::Display(IPanelDevice &device) :
-    panel_(device)
+    panel_(device),
+    lv_tick_timer_(nullptr)
 {
   if (!lv_is_initialized()) {
     ESP_LOGI(TAG, "Initialize LVGL");
@@ -47,19 +48,11 @@ Display::Display(IPanelDevice &device) :
       .on_color_trans_done = Display::lvgl_flush_ready,
   };
   ESP_ERROR_CHECK(
-      esp_lcd_panel_io_register_event_callbacks(panel_.esp_io_handle_, &cbs,
+      esp_lcd_panel_io_register_event_callbacks(panel_.esp_io_, &cbs,
                                                 lv_display_));
+  register_lvgl_tick_timer();
 
-  ESP_LOGI(TAG, "Use esp_timer to increase LVGL tick");
+  // TODO: What is this
-  const esp_timer_create_args_t lvgl_tick_timer_args = {
-      .callback = &Display::lvgl_increase_tick,
-      .name = "lvgl_tick"
-  };
-  esp_timer_handle_t lvgl_tick_timer = nullptr;
-  ESP_ERROR_CHECK(esp_timer_create(&lvgl_tick_timer_args, &lvgl_tick_timer));
-  ESP_ERROR_CHECK(esp_timer_start_periodic(lvgl_tick_timer,
-                                           LVGL_TICK_PERIOD_MS * 1000));
-
   ESP_LOGI(TAG, "Create LVGL task");
   xTaskCreate(Display::lvgl_port_task, "LVGL", LVGL_TASK_STACK_SIZE,
               nullptr, LVGL_TASK_PRIORITY, nullptr);
@@ -98,7 +91,7 @@ bool Display::lvgl_flush_ready(esp_lcd_panel_io_handle_t,
 }
 
 void Display::lvgl_flush_cb(lv_display_t *display, const lv_area_t *area,
-                            uint8_t *px_map)
+                            uint8_t *px_map) // NOLINT(*-non-const-parameter)
 {
   auto panel_handle =
       (esp_lcd_panel_handle_t) lv_display_get_user_data(display);
@@ -158,3 +151,16 @@ void Display::lvgl_increase_tick(void *)
     usleep(1000 * time_till_next_ms);
   }
 }
+
+void Display::register_lvgl_tick_timer() // NOLINT(*-convert-member-functions-to-static)
+{
+  ESP_LOGI(TAG, "Use esp_timer to increase LVGL tick");
+  const esp_timer_create_args_t lvgl_tick_timer_args = {
+      .callback = &Display::lvgl_increase_tick,
+      .name = "lvgl_tick"
+  };
+  esp_timer_handle_t lvgl_tick_timer = nullptr;
+  ESP_ERROR_CHECK(esp_timer_create(&lvgl_tick_timer_args, &lvgl_tick_timer));
+  ESP_ERROR_CHECK(esp_timer_start_periodic(lvgl_tick_timer,
+                                           LVGL_TICK_PERIOD_MS * 1000));
+}

esp/cpp/07_lcd-panel/main/display.h

@@ -4,6 +4,7 @@
 #include <widgets/label/lv_label.h>
 
 #include <unordered_map>
+#include <esp_timer.h>
 
 #include "panel.h"
 
@@ -43,6 +44,8 @@ public:
   [[noreturn]] static void lvgl_port_task(void *arg);
 
 private:
+  void register_lvgl_tick_timer();
+
   Panel panel_;
 
   lv_display_t *lv_display_;
@@ -55,6 +58,9 @@ private:
   // @sa lv_display_get_screen_active
   std::unordered_map<const char *, lv_obj_t *> lv_objects_;
 
+  // TODO: This could be a private struct
+  esp_timer_handle_t lv_tick_timer_;
+
   struct ScopedLock {
     explicit ScopedLock() { _lock_acquire(&lv_lock_); }
 

esp/cpp/07_lcd-panel/main/i2c.h

@@ -30,6 +30,7 @@ struct I2C {
 
   ~I2C() = default;
 
+  // TODO: Can you use the I2C get_master_bus API in a static method?
   i2c_master_bus_handle_t esp_i2c_bus_;
 
   int rst_num_;

esp/cpp/07_lcd-panel/main/main.cpp

@@ -4,7 +4,7 @@
 // Pin may vary based on your schematic.
 #define PIN_SDA                GPIO_NUM_21
 #define PIN_SCL                GPIO_NUM_22
-#define PIN_RST                -1
+#define PIN_RST                (-1)
 
 I2C i2c(PIN_SDA, PIN_SCL, PIN_RST);
 

esp/cpp/07_lcd-panel/main/panel.cpp

@@ -3,7 +3,7 @@
 
 Panel::Panel(IPanelDevice &device) :
     device_(&device),
-    esp_io_handle_(nullptr),
+    esp_io_(nullptr),
     esp_panel_(nullptr),
     esp_panel_config_(
         (esp_lcd_panel_dev_config_t) {
@@ -13,9 +13,9 @@ Panel::Panel(IPanelDevice &device) :
         }
     )
 {
-  esp_io_handle_ = device_->create_io_handle();
+  esp_io_ = device_->create_io_handle();
 
-  device_->create_panel(esp_panel_config_, esp_io_handle_, esp_panel_);
+  device_->create_panel(esp_panel_config_, esp_io_, esp_panel_);
 
   ESP_LOGI(TAG, "Resetting panel display");
   ESP_ERROR_CHECK(esp_lcd_panel_reset(esp_panel_));

esp/cpp/07_lcd-panel/main/panel.h

@@ -11,7 +11,7 @@ public:
 
   IPanelDevice *device_;
 
-  esp_lcd_panel_io_handle_t esp_io_handle_;
+  esp_lcd_panel_io_handle_t esp_io_;
 
   esp_lcd_panel_handle_t esp_panel_;
 

esp/cpp/07_lcd-panel/main/ssd1306.cpp

@@ -22,12 +22,3 @@ SSD1306::SSD1306(I2C& i2c,
     ),
     ssd1306_config_(config)
 { }
-
-void SSD1306::init_panel(esp_lcd_panel_dev_config_t &config,
-                         esp_lcd_panel_io_handle_t io,
-                         esp_lcd_panel_handle_t &panel)
-{
-  // Allocate SSD1306 panel handle.
-  config.vendor_config = &ssd1306_config_;
-  ESP_ERROR_CHECK(esp_lcd_new_panel_ssd1306(io, &config, &panel));
-}

esp/cpp/07_lcd-panel/main/ssd1306.h

@@ -1,3 +1,16 @@
+/*
+ * https://docs.espressif.com/projects/esp-idf/en/v5.3.2/esp32/api-reference/peripherals/lcd/index.html#functional-overview
+ *
+ * Implementing the interface draw to an LCD using various interface modes.
+ * I2C interface mode is SSD1306
+ * SPI interface mode is ST7789
+ * I80 interface mode is NT35510 or ST7789
+ *
+ * Actually, I think any driver can be used with any interface mode
+ * Along with additional third party drivers via the component manager
+ * https://github.com/espressif/esp-idf/tree/0d6099ec533c4b647fb7a7b0b8942bc7aeb82f90/examples/peripherals/lcd/spi_lcd_touch#spi-lcd-and-touch-panel-example
+ */
+
 #ifndef SSD1306_H
 #define SSD1306_H
 
@@ -45,7 +58,10 @@ public:
 private:
   void init_panel(esp_lcd_panel_dev_config_t &config,
                   esp_lcd_panel_io_handle_t io,
-                  esp_lcd_panel_handle_t &panel) override;
+                  esp_lcd_panel_handle_t &panel) override
+  {
+    ESP_ERROR_CHECK(esp_lcd_new_panel_ssd1306(io, &config, &panel));
+  }
 };
 
 #endif // SSD1306_H