iot增加屏幕背光亮度调节 (#150)

main/display/display.h

@@ -23,6 +23,7 @@ public:
     virtual void SetEmotion(const std::string &emotion);
     virtual void SetChatMessage(const std::string &role, const std::string &content);
     virtual void SetIcon(const char* icon);
+    virtual void SetBacklight(uint8_t brightness) = 0;
 
     int width() const { return width_; }
     int height() const { return height_; }

main/display/lcd_display.cc

@@ -132,7 +132,7 @@ void LcdDisplay::InitializeBacklight(gpio_num_t backlight_pin) {
         .speed_mode = LEDC_LOW_SPEED_MODE,
         .duty_resolution = LEDC_TIMER_10_BIT,
         .timer_num = LEDC_TIMER_0,
-        .freq_hz = 5000,
+        .freq_hz = 20000,//背光pwm频率需要高一点，防止电感啸叫
         .clk_cfg = LEDC_AUTO_CLK,
         .deconfigure = false
     };

main/display/lcd_display.h

@@ -31,7 +31,6 @@ protected:
     DisplayFonts fonts_;
 
     void InitializeBacklight(gpio_num_t backlight_pin);
-    void SetBacklight(uint8_t brightness);
 
     virtual void SetupUI();
     virtual bool Lock(int timeout_ms = 0) override;
@@ -47,6 +46,7 @@ public:
     void SetChatMessage(const std::string &role, const std::string &content) override;
     void SetEmotion(const std::string &emotion) override;
     void SetIcon(const char* icon) override;
+    void SetBacklight(uint8_t brightness);
 };
 
 #endif // LCD_DISPLAY_H

main/display/no_display.h

@@ -7,7 +7,9 @@ class NoDisplay : public Display {
 private:
     virtual bool Lock(int timeout_ms = 0) override;
     virtual void Unlock() override;
-
+    virtual void SetBacklight(uint8_t brightness) override {
+        // 空实现，因为这是一个无显示设备
+    }
 public:
     NoDisplay();
     ~NoDisplay();