test(esp_lcd): test lcd sleep function

components/esp_lcd/test_apps/spi_lcd/main/test_spi_lcd_panel.c

@@ -90,14 +90,29 @@ static void lcd_panel_test(esp_lcd_panel_io_handle_t io_handle, esp_lcd_panel_ha
     // turn on backlight
     gpio_set_level(TEST_LCD_BK_LIGHT_GPIO, 1);
 
-    for (int i = 0; i < 200; i++) {
+    for (int i = 0; i < 100; i++) {
         uint8_t color_byte = rand() & 0xFF;
         int x_start = rand() % (TEST_LCD_H_RES - 200);
         int y_start = rand() % (TEST_LCD_V_RES - 200);
         memset(img, color_byte, TEST_IMG_SIZE);
         esp_lcd_panel_draw_bitmap(panel_handle, x_start, y_start, x_start + 200, y_start + 200, img);
     }
-    // turn off screen
+
+    printf("go into sleep mode\r\n");
+    esp_lcd_panel_disp_sleep(panel_handle, true);
+    vTaskDelay(pdMS_TO_TICKS(500));
+    printf("exit sleep mode\r\n");
+    esp_lcd_panel_disp_sleep(panel_handle, false);
+
+    for (int i = 0; i < 100; i++) {
+        uint8_t color_byte = rand() & 0xFF;
+        int x_start = rand() % (TEST_LCD_H_RES - 200);
+        int y_start = rand() % (TEST_LCD_V_RES - 200);
+        memset(img, color_byte, TEST_IMG_SIZE);
+        esp_lcd_panel_draw_bitmap(panel_handle, x_start, y_start, x_start + 200, y_start + 200, img);
+    }
+
+    printf("turn off the panel\r\n");
     esp_lcd_panel_disp_on_off(panel_handle, false);
     TEST_ESP_OK(esp_lcd_panel_del(panel_handle));
     TEST_ESP_OK(esp_lcd_panel_io_del(io_handle));
@@ -247,12 +262,14 @@ TEST_CASE("spi_lcd_send_colors_to_fixed_region", "[lcd]")
         TEST_ESP_OK(esp_lcd_panel_io_tx_color(io_handle, -1, color_data + i * color_size_per_step, color_size_per_step));
     }
     vTaskDelay(pdMS_TO_TICKS(1000));
-    // change to another color
+
+    printf("change to another color\r\n");
     color_byte = rand() & 0xFF;
     memset(color_data, color_byte, color_size);
     for (int i = 0; i < steps; i++) {
         TEST_ESP_OK(esp_lcd_panel_io_tx_color(io_handle, -1, color_data + i * color_size_per_step, color_size_per_step));
     }
+    vTaskDelay(pdMS_TO_TICKS(1000));
 
     TEST_ESP_OK(esp_lcd_panel_del(panel_handle));
     TEST_ESP_OK(esp_lcd_panel_io_del(io_handle));

docs/en/api-reference/peripherals/lcd.rst

@@ -454,7 +454,8 @@ LCD Panel IO Operations
 * :cpp:func:`esp_lcd_panel_reset` can reset the LCD panel.
 * :cpp:func:`esp_lcd_panel_init` performs a basic initialization of the panel. To perform more manufacture specific initialization, please go to :ref:`steps_add_manufacture_init`.
 * Through combined use of :cpp:func:`esp_lcd_panel_swap_xy` and :cpp:func:`esp_lcd_panel_mirror`, you can rotate the LCD screen.
-* :cpp:func:`esp_lcd_panel_disp_on_off` can turn on or off the LCD screen (different from LCD backlight).
+* :cpp:func:`esp_lcd_panel_disp_on_off` can turn on or off the LCD screen by cutting down the output path from the frame buffer to the LCD screen.
+* :cpp:func:`esp_lcd_panel_disp_sleep` can reduce the power consumption of the LCD screen by entering the sleep mode. The internal frame buffer is still retained.
 * :cpp:func:`esp_lcd_panel_draw_bitmap` is the most significant function, which does the magic to draw the user provided color buffer to the LCD screen, where the draw window is also configurable.
 
 .. _steps_add_manufacture_init: