Add panel orientation setting for upside-down mounting (#455)

Adds a display.hardware.orientation config field ("normal" / "180")
so panels mounted upside down (e.g. to put the Pi/wiring on a more
convenient side) render correctly without custom pixel_mapper_config
edits. Composes onto the existing pixel_mapper_config as a trailing
"Rotate:180" mapper, so it stays independent of any custom mapper
string (e.g. U-mapper chain layouts) already in use.

Exposed as a "Panel Orientation" dropdown in the web UI's Display
settings, validated server-side, and documented in README and
CONFIG_REFERENCE.


Claude-Session: https://claude.ai/code/session_01FakipqMDHQLpsFjTuBdSFQ

Co-authored-by: Claude <noreply@anthropic.com>

README.md

@@ -600,6 +600,14 @@ These settings are typically only needed for non-standard panels or custom confi
   - Leave empty unless you need custom mapping
   - See rpi-rgb-led-matrix documentation for full options
 
+- **`orientation`** (string, default: "normal")
+  - Rotates the rendered image to match how the panel is physically mounted
+  - Set to `"180"` (or use the "Upside Down" option in the web UI's Display
+    settings) if the panel is mounted upside down — useful for optimizing
+    where the Raspberry Pi and wiring sit relative to the mounting location
+  - Applied independently of `pixel_mapper_config` (appended as a trailing
+    `Rotate:180` mapper), so custom mapper configs keep working alongside it
+
 - **`row_address_type`** (integer, default: 0)
   - How rows are addressed on the panel
   - Most panels use 0 (direct addressing)

config/config.template.json

@@ -112,6 +112,7 @@
             "led_rgb_sequence": "RGB",
             "limit_refresh_rate_hz": 100,
             "pixel_mapper_config": "",
+            "orientation": "normal",
             "row_address_type": 0,
             "multiplexing": 0,
             "panel_type": ""

docs/CONFIG_REFERENCE.md

@@ -66,6 +66,7 @@ in `DisplayManager` (`src/display_manager.py`, ~lines 270–295).
 | `led_rgb_sequence` | string, `"RGB"` |
 | `limit_refresh_rate_hz` | int, `100` (code default 90) |
 | `pixel_mapper_config` | string, `""` — e.g. `"U-mapper"` / `"Rotate:90"` |
+| `orientation` | string, `"normal"` — `"180"` rotates the rendered image 180° for panels physically mounted upside down (e.g. to move the Pi/wiring to a more convenient side); composed onto `pixel_mapper_config` as a trailing `Rotate:180` mapper, so it stays independent of any custom `pixel_mapper_config` value |
 | `row_address_type` | int, `0` — non-standard panel row addressing |
 | `multiplexing` | int, `0` — panel multiplexing scheme |
 | `panel_type` | string, `""` — set to `"FM6126A"` or `"FM6127"` for panels needing init |

src/display_manager.py

@@ -258,6 +258,26 @@ class DisplayManager:
         # Initialize managers
         # Calendar manager is now initialized by DisplayController
         
+    # Orientation setting -> rpi-rgb-led-matrix "Rotate:<deg>" pixel-mapper suffix.
+    # "normal" needs no suffix since 0 degrees is the identity transform.
+    _ORIENTATION_ROTATE_DEGREES = {'normal': None, '90': 90, '180': 180, '270': 270}
+
+    def _build_pixel_mapper_config(self, hardware_config: dict) -> str:
+        """Compose the raw pixel_mapper_config string with the orientation setting.
+
+        `pixel_mapper_config` stays available as a free-form advanced field (e.g.
+        for "U-mapper" chain layouts); `orientation` is the user-facing dropdown
+        for physical mounting (e.g. panels mounted upside down) and is appended as
+        a "Rotate:<deg>" mapper rather than overwriting any existing config.
+        """
+        base_mapper = (hardware_config.get('pixel_mapper_config') or '').strip()
+        orientation = hardware_config.get('orientation', 'normal')
+        degrees = self._ORIENTATION_ROTATE_DEGREES.get(orientation)
+        if degrees is None:
+            return base_mapper
+        rotate_mapper = f'Rotate:{degrees}'
+        return f'{base_mapper};{rotate_mapper}' if base_mapper else rotate_mapper
+
     def _setup_matrix(self):
         """Initialize the RGB matrix with configuration settings."""
         _init_error_str = None
@@ -283,7 +303,7 @@ class DisplayManager:
             options.pwm_bits = hardware_config.get('pwm_bits', 10)
             options.pwm_lsb_nanoseconds = hardware_config.get('pwm_lsb_nanoseconds', 150)
             options.led_rgb_sequence = hardware_config.get('led_rgb_sequence', 'RGB')
-            options.pixel_mapper_config = hardware_config.get('pixel_mapper_config', '')
+            options.pixel_mapper_config = self._build_pixel_mapper_config(hardware_config)
             options.row_address_type = hardware_config.get('row_address_type', 0)
             options.multiplexing = hardware_config.get('multiplexing', 0)
             options.panel_type = hardware_config.get('panel_type', '')

test/test_display_manager.py

@@ -237,3 +237,45 @@ class TestDisplayManagerDoubleSided:
                                 suppress_test_pattern=True)
             assert dm.set_brightness(70) is True
             assert mock_rgb_matrix['matrix_instance'].brightness == 70
+
+
+class TestDisplayManagerOrientation:
+    """The orientation setting composes onto pixel_mapper_config for panels
+    mounted upside down, without disturbing a custom pixel_mapper_config."""
+
+    def _config(self, **hardware_overrides):
+        config = {
+            'display': {
+                'hardware': {
+                    'rows': 32, 'cols': 64, 'chain_length': 2, 'parallel': 1,
+                    'hardware_mapping': 'adafruit-hat-pwm', 'brightness': 90,
+                },
+                'runtime': {'gpio_slowdown': 2},
+            },
+            'timezone': 'UTC',
+            'plugin_system': {'plugins_directory': 'plugins'},
+        }
+        config['display']['hardware'].update(hardware_overrides)
+        return config
+
+    def test_default_orientation_leaves_pixel_mapper_config_untouched(self, mock_rgb_matrix):
+        DisplayManager._instance = None
+        with patch.dict('os.environ', {'EMULATOR': 'false'}):
+            DisplayManager(self._config(), suppress_test_pattern=True)
+            options = mock_rgb_matrix['options_class'].return_value
+            assert options.pixel_mapper_config == ''
+
+    def test_orientation_180_appends_rotate_mapper(self, mock_rgb_matrix):
+        DisplayManager._instance = None
+        with patch.dict('os.environ', {'EMULATOR': 'false'}):
+            DisplayManager(self._config(orientation='180'), suppress_test_pattern=True)
+            options = mock_rgb_matrix['options_class'].return_value
+            assert options.pixel_mapper_config == 'Rotate:180'
+
+    def test_orientation_180_composes_with_existing_pixel_mapper_config(self, mock_rgb_matrix):
+        DisplayManager._instance = None
+        with patch.dict('os.environ', {'EMULATOR': 'false'}):
+            DisplayManager(self._config(orientation='180', pixel_mapper_config='U-mapper'),
+                           suppress_test_pattern=True)
+            options = mock_rgb_matrix['options_class'].return_value
+            assert options.pixel_mapper_config == 'U-mapper;Rotate:180'

web_interface/blueprints/api_v3.py

@@ -796,7 +796,7 @@ def save_main_config():
                          'gpio_slowdown', 'rp1_rio', 'scan_mode', 'disable_hardware_pulsing', 'inverse_colors', 'show_refresh_rate',
                          'pwm_bits', 'pwm_dither_bits', 'pwm_lsb_nanoseconds', 'limit_refresh_rate_hz', 'use_short_date_format',
                          'max_dynamic_duration_seconds', 'led_rgb_sequence', 'multiplexing', 'panel_type',
-                         'row_address_type', 'pixel_mapper_config']
+                         'row_address_type', 'pixel_mapper_config', 'orientation']
 
         if any(k in data for k in display_fields):
             if 'display' not in current_config:
@@ -831,6 +831,11 @@ def save_main_config():
             if 'pixel_mapper_config' in data and not isinstance(data['pixel_mapper_config'], str):
                 return jsonify({'status': 'error', 'message': 'pixel_mapper_config must be a string (e.g. "U-mapper;Rotate:90" or empty)'}), 400
 
+            # Validate orientation (physical mounting rotation; composed onto pixel_mapper_config at runtime)
+            ORIENTATION_ALLOWED = {'normal', '180'}
+            if 'orientation' in data and data['orientation'] not in ORIENTATION_ALLOWED:
+                return jsonify({'status': 'error', 'message': f"Invalid orientation '{data['orientation']}'. Allowed values: {', '.join(sorted(ORIENTATION_ALLOWED))}"}), 400
+
             # Validate row_address_type
             if 'row_address_type' in data:
                 try:
@@ -844,7 +849,7 @@ def save_main_config():
             for field in ['rows', 'cols', 'chain_length', 'parallel', 'brightness', 'hardware_mapping', 'scan_mode',
                          'pwm_bits', 'pwm_dither_bits', 'pwm_lsb_nanoseconds', 'limit_refresh_rate_hz',
                          'led_rgb_sequence', 'multiplexing', 'panel_type', 'row_address_type',
-                         'pixel_mapper_config']:
+                         'pixel_mapper_config', 'orientation']:
                 if field in data:
                     if field in ['rows', 'cols', 'chain_length', 'parallel', 'brightness', 'scan_mode',
                                'pwm_bits', 'pwm_dither_bits', 'pwm_lsb_nanoseconds', 'limit_refresh_rate_hz',

web_interface/templates/v3/partials/display.html

@@ -117,6 +117,14 @@
                     </select>
                 </div>
 
+                <div class="form-group" id="setting-display-orientation" data-setting-key="display.hardware.orientation">
+                    <label for="orientation" class="block text-sm font-medium text-gray-700">Panel Orientation{{ ui.help_tip('Rotates the rendered image to match how the panel is physically mounted.\nUse "Upside Down" if you flipped the panel 180° to move the Raspberry Pi / wiring to a more convenient side.', 'Panel Orientation') }}</label>
+                    <select id="orientation" name="orientation" class="form-control">
+                        <option value="normal" {% if main_config.display.hardware.get('orientation', 'normal') == "normal" %}selected{% endif %}>Normal</option>
+                        <option value="180" {% if main_config.display.hardware.get('orientation', 'normal') == "180" %}selected{% endif %}>Upside Down (180°)</option>
+                    </select>
+                </div>
+
                 <div class="form-group" id="setting-display-led_rgb_sequence" data-setting-key="display.hardware.led_rgb_sequence">
                     <label for="led_rgb_sequence" class="block text-sm font-medium text-gray-700">LED RGB Sequence{{ ui.help_tip('Order the panel expects color channels in.\nChange this only if reds/greens/blues look swapped. Default: RGB.', 'LED RGB Sequence') }}</label>
                     <select id="led_rgb_sequence" name="led_rgb_sequence" class="form-control">