Add brightness setting

README.md

@@ -141,6 +141,22 @@ void rgb_demo(void) {
 }
 ```
 
+### HSV + Global Brightness
+
+```c
+#include "led_manager.h"
+
+void hsv_demo(void) {
+    led_manager_init(GPIO_NUM_8);
+
+    // Set a teal color using HSV
+    led_manager_set_hsv(180, 255, 200);
+
+    // Dim the LED globally without changing hue/saturation
+    led_manager_set_brightness(64);
+}
+```
+
 ## 📚 API Reference
 
 ### Data Types
@@ -354,6 +370,61 @@ led_manager_set_rgb(255, 165, 0);    // Orange variant
 led_manager_set_rgb(75, 0, 130);     // Indigo
 ```
 
+##### `esp_err_t led_manager_set_hsv(uint16_t hue, uint8_t saturation, uint8_t value)`
+
+Set LED color using HSV values.
+
+**Parameters:**
+
+- `hue`: Hue component (0-360)
+- `saturation`: Saturation component (0-255)
+- `value`: Value/brightness component (0-255)
+
+**Returns:**
+
+- `ESP_OK`: Color set successfully
+- `ESP_ERR_INVALID_STATE`: LED manager not initialized
+- Hardware error codes on failure
+
+**Technical Details:**
+
+- Stores HSV as the current color for blinking
+- Global brightness scales the `value` component
+- If blinking is active, color updates take effect on the next blink cycle
+
+**Example:**
+
+```c
+// Teal-ish color
+led_manager_set_hsv(180, 255, 200);
+```
+
+##### `esp_err_t led_manager_set_brightness(uint8_t brightness)`
+
+Set global brightness without changing the current hue/saturation.
+
+**Parameters:**
+
+- `brightness`: Brightness value (0-255)
+
+**Returns:**
+
+- `ESP_OK`: Brightness updated successfully
+- `ESP_ERR_INVALID_STATE`: LED manager not initialized
+- Hardware error codes on failure
+
+**Technical Details:**
+
+- Scales the current HSV value when pushing to the LED
+- If blinking is active, brightness applies to subsequent blink updates
+
+**Example:**
+
+```c
+// Dim to 25%
+led_manager_set_brightness(64);
+```
+
 #### Control Functions
 
 ##### `esp_err_t led_manager_clear(void)`