Trackball Pointer Mode & driver rewrite (#453)

Devices/lilygo-tdeck/Source/devices/KeyboardBacklight.cpp

@@ -1,16 +1,31 @@
 #include "KeyboardBacklight.h"
 #include <KeyboardBacklight/KeyboardBacklight.h>  // Driver
 #include <Tactility/hal/i2c/I2c.h>
+#include <Tactility/settings/KeyboardSettings.h>
 
 // TODO: Add Mutex and consider refactoring into a class
 bool KeyboardBacklightDevice::start() {
     if (initialized) {
         return true;
     }
-    
+
     // T-Deck uses I2C_NUM_0 for internal peripherals
     initialized = keyboardbacklight::init(I2C_NUM_0);
-    return initialized;
+    if (!initialized) {
+        return false;
+    }
+
+    // Backlight doesn't seem to turn on until toggled on and off from keyboard settings...
+    // Or let the display and backlight sleep then wake it up.
+    // Then it works fine...until reboot, then you need to toggle again.
+    // The current keyboard firmware sets backlight duty to 0 on boot.
+    // https://github.com/Xinyuan-LilyGO/T-Deck/blob/master/firmware/T-Keyboard_Keyboard_ESP32C3_250620.bin
+    // https://github.com/Xinyuan-LilyGO/T-Deck/blob/master/examples/Keyboard_ESP32C3/Keyboard_ESP32C3.ino#L25
+    // https://github.com/Xinyuan-LilyGO/T-Deck/blob/master/examples/Keyboard_ESP32C3/Keyboard_ESP32C3.ino#L217
+    auto kbSettings = tt::settings::keyboard::loadOrGetDefault();
+    keyboardbacklight::setBrightness(kbSettings.backlightEnabled ? kbSettings.backlightBrightness : 0);
+
+    return true;
 }
 
 bool KeyboardBacklightDevice::stop() {