feature: Added brightness control feature.

Author: eleonel

README.md

@@ -156,6 +156,9 @@ WebScreen uses a JSON configuration file stored on the SD card as `/webscreen.js
     "background": "#2980b9",
     "foreground": "#00fff1"
   },
+  "display": {
+    "brightness": 200
+  },
   "script": "app.js"
 }
 ```
@@ -169,6 +172,7 @@ WebScreen uses a JSON configuration file stored on the SD card as `/webscreen.js
 | **settings.mqtt** | `enabled` | Enable MQTT functionality | `false` |
 | **screen** | `background` | Background color (hex format) | `"#000000"` |
 | | `foreground` | Text/foreground color (hex) | `"#FFFFFF"` |
+| **display** | `brightness` | Display brightness (0-255) | `200` |
 | **Root** | `script` | JavaScript file to execute | `"app.js"` |
 
 ### Example Configurations
@@ -374,6 +378,7 @@ WebScreen includes a comprehensive serial command system for interactive develop
 /info                    - Show device information and version
 /write <filename>        - Interactive JavaScript editor
 /load <script.js>        - Switch to different JS application
+/brightness <0-255>      - Set display brightness (no args to query current)
 /reboot                  - Restart the device
 ```
 
@@ -448,6 +453,7 @@ The firmware exposes numerous functions to your JavaScript applications. Some hi
 - **HTTP:** `http_get()`, `http_post()`, `http_delete()` (all support custom ports like `http://host:port/path`), `http_set_ca_cert_from_sd()`, `parse_json_value()`
 - **SD Card:** `sd_read_file()`, `sd_write_file()`, `sd_list_dir()`, `sd_delete_file()`
 - **BLE:** `ble_init()`, `ble_is_connected()`, `ble_write()`
+- **Display:** `set_brightness()`, `get_brightness()`
 - **UI Drawing:** `draw_label()`, `draw_rect()`, `show_image()`, `create_label()`, `label_set_text()`
 - **Image Handling:** `create_image()`, `create_image_from_ram()`, `rotate_obj()`, `move_obj()`, `animate_obj()`
 - **Styles & Layout:** `create_style()`, `obj_add_style()`, `style_set_*()`, `obj_align()`

docs/API.md

@@ -6,19 +6,23 @@ WebScreen exposes a comprehensive set of functions to JavaScript applications ru
 
 ```json
 {
-  "wifi": {
-    "ssid": "MyNetwork",
-    "password": "MyPassword",
-    "enabled": true
+  "settings": {
+    "wifi": {
+      "ssid": "MyNetwork",
+      "pass": "MyPassword"
+    },
+    "mqtt": {
+      "enabled": false
+    }
   },
-  "mqtt": {
-    "enabled": false
+  "screen": {
+    "background": "#2980b9",
+    "foreground": "#00fff1"
   },
   "display": {
-    "background_color": "#2980b9",
-    "foreground_color": "#00fff1"
+    "brightness": 200
   },
-  "script_file": "my_app.js"
+  "script": "my_app.js"
 }
 ```
 
@@ -40,6 +44,23 @@ The following functions are available in your JavaScript applications:
 - **create_timer()**
   Create a timer object for periodic execution.
 
+### Display Control
+
+- **set_brightness(value)**
+  Set the display brightness. Value ranges from 0 (off) to 255 (maximum). Returns the applied brightness value, or -1 on error.
+  ```javascript
+  set_brightness(200);   // Set brightness to ~78%
+  set_brightness(0);     // Turn off display backlight
+  set_brightness(255);   // Maximum brightness
+  ```
+
+- **get_brightness()**
+  Returns the current display brightness value (0-255).
+  ```javascript
+  let current = get_brightness();
+  print("Current brightness: " + numberToString(current));
+  ```
+
 ### String Utilities
 
 - **str_index_of(haystack, needle)**  

docs/SerialCommands.md

@@ -60,6 +60,7 @@ WebScreen> /help
 /wget <url> [file]       - Download file from URL to SD card
 /ping <host>             - Test network connectivity
 /backup [save|restore]   - Backup/restore configuration
+/brightness <0-255>      - Set display brightness
 /monitor [cpu|mem|net]   - Live system monitoring
 /reboot                  - Restart the device
 
@@ -127,6 +128,32 @@ WebScreen Version: 2.0.0
 Build Date: Dec 15 2024 14:30:25
 ```
 
+#### `/brightness <0-255>`
+Sets or queries the display brightness level.
+
+**Usage:**
+```
+WebScreen> /brightness
+Current brightness: 200
+
+WebScreen> /brightness 150
+[OK] Brightness set to 150
+
+WebScreen> /brightness 255
+[OK] Brightness set to 255
+```
+
+**Parameters:**
+- **No argument**: Displays the current brightness level
+- **0-255**: Sets the brightness to the specified value (0 = off, 255 = maximum)
+
+**Notes:**
+- Changes take effect immediately on the AMOLED display
+- To persist brightness across reboots, also set `display.brightness` in the configuration:
+  ```
+  /config set display.brightness 150
+  ```
+
 #### `/reboot` or `/restart`
 Restarts the WebScreen device. Useful for applying configuration changes or recovering from errors.