Update T-Deck keyboard example

examples/Keyboard_T_Deck_Master/Keyboard_T_Deck_Master.ino

@@ -9,13 +9,40 @@
 #include <Arduino.h>
 #include <Wire.h>
 
-#define LILYGO_KB_SLAVE_ADDRESS     0x55
-
+#define LILYGO_KB_SLAVE_ADDRESS             0x55
+#define LILYGO_KB_BRIGHTNESS_CMD            0x01
+#define LILYGO_KB_ALT_B_BRIGHTNESS_CMD      0x02
 
 #define BOARD_POWERON       10
 #define BOARD_I2C_SDA       18
 #define BOARD_I2C_SCL       8
 
+/*
+* Dynamically modify backlight brightness at runtime
+* Brightness Range: 0 ~ 255
+* */
+void setKeyboardBrightness(uint8_t value)
+{
+    Wire.beginTransmission(LILYGO_KB_SLAVE_ADDRESS);
+    Wire.write(LILYGO_KB_BRIGHTNESS_CMD);
+    Wire.write(value);
+    Wire.endTransmission();
+}
+
+/*
+* Set the default backlight brightness level. If the user sets the backlight to 0
+* via setKeyboardBrightness, the default brightness is used when pressing ALT+B,
+* rather than the backlight brightness level set by the user. This ensures that
+* pressing ALT+B can respond to the backlight being turned on and off normally.
+* Brightness Range: 30 ~ 255
+* */
+void setKeyboardDefaultBrightness(uint8_t value)
+{
+    Wire.beginTransmission(LILYGO_KB_SLAVE_ADDRESS);
+    Wire.write(LILYGO_KB_ALT_B_BRIGHTNESS_CMD);
+    Wire.write(value);
+    Wire.endTransmission();
+}
 
 void setup()
 {
@@ -36,12 +63,16 @@ void setup()
     Wire.requestFrom(LILYGO_KB_SLAVE_ADDRESS, 1);
     if (Wire.read() == -1) {
         while (1) {
-            Serial.println("LILYGO Keyboad not online .");
+            Serial.println("LILYGO Keyboard not online .");
             delay(1000);
         }
     }
+    // Set the default backlight brightness level.
+    setKeyboardDefaultBrightness(127);
+
 }
 
+bool test_bl_done = false;
 void loop()
 {
     // Read key value from esp32c3
@@ -54,6 +85,22 @@ void loop()
             Serial.println(keyValue);
         }
     }
+
+    // Test brightness
+    static uint32_t interval = 0;
+    static uint8_t brightness = 0;
+    if (millis() > interval && !test_bl_done) {
+        // Dynamically modify backlight brightness at runtime
+        setKeyboardBrightness(brightness);
+        brightness++;
+        brightness %= 255;
+        if (brightness == 0) {
+            Serial.println("Test brightness done..., Press ALT+B test default brightness level");
+            setKeyboardBrightness(brightness);
+            test_bl_done = true;
+        }
+        interval = millis() + 50;
+    }
     delay(5);
 }