Stop error resulting from lack of pwm overlay support

backend_py/src/lights/rpi_pwm_hardware.py

@@ -1,4 +1,4 @@
-from rpi_hardware_pwm import HardwarePWM
+from rpi_hardware_pwm import HardwarePWM, HardwarePWMException
 from .pwm_controller import PWMController
 from typing import Dict
 import logging
@@ -9,6 +9,8 @@ class RPiHardwarePWMController(PWMController):
     def __init__(self, chip=0, pins=None) -> None:
         super().__init__()
 
+        self.pwm_supported = True
+
         if pins is None:
             pins = {
                 18: 0,
@@ -19,11 +21,23 @@ def __init__(self, chip=0, pins=None) -> None:
         self.pwm_objects: Dict[int, HardwarePWM] = {}
 
         for pin in self.PWM_PINS.keys():
-            self.pwm_objects[pin] = HardwarePWM(pwm_channel=self.PWM_PINS[pin], hz=7812.5, chip=chip)
+            try:
+                self.pwm_objects[pin] = HardwarePWM(pwm_channel=self.PWM_PINS[pin], hz=7812.5, chip=chip)
+            except HardwarePWMException:
+                logging.warning('Hardware PWM is not enabled. Need to add \'dtoverlay=pwm-2chan\' to /boot/config.txt and reboot.')
+                self.pwm_supported = False
+                break
             self.pwm_objects[pin].start(0)
 
+        # Make sure the objects are not initialized
+        if not self.pwm_supported:
+            self.pwm_objects = {}
+
     def is_pwm_pin(self, pin: int) -> bool:
-        return pin in self.PWM_PINS.keys()
+        '''
+        Return true if the pin is supported but will always return false if pwm is not supported entirely
+        '''
+        return pin in self.PWM_PINS.keys() if self.pwm_supported else False
 
     def disable_pin(self, pin: int):
         # FIXME: Not implemented
@@ -42,4 +56,4 @@ def cleanup(self):
             pwm.stop()
 
     def get_pins(self):
-        return self.PWM_PINS.keys()
+        return self.PWM_PINS.keys() if self.pwm_supported else []

backend_py/src/lights/utils.py

@@ -1,25 +1,47 @@
 import logging
-from .fake_pwm import FakePWMController
+# from .fake_pwm import FakePWMController
+import re
+import os
 
-def get_rpi_model():
+def is_overlay_loaded():
+    '''
+    Based on function from rpi_hardware_pwm
+    '''
+    chippath = '/sys/class/pwm/pwmchip0'
+    return os.path.isdir(chippath)
+
+def get_rpi_version():
     try:
-        with open('/sys/firmware/devicetree/base/model', 'r') as m:
-            model = m.read().lower()
-            if 'raspberry pi 3' in model:
-                return 3
-            elif 'raspberry pi 4' in model:
-                return 4
-            elif 'raspberry pi 5' in model:
-                return 5
+        # Read the device model from the file
+        with open('/sys/firmware/devicetree/base/model', 'r') as f:
+            model = f.read().strip()
+
+        # Check if the device is a Raspberry Pi
+        if "Raspberry Pi" in model:
+            # Extract the version number using regex
+            match = re.search(r'Raspberry Pi\s+(\d+)', model)
+            if match:
+                # Return the numeric model version
+                version = int(match.group(1))
+                return version
+            else:
+                # Fallback if no version number is found
+                return None
+        else:
             return None
-    except:
+
+    except FileNotFoundError:
+        # In case the file doesn't exist or is not accessible
         return None
 
 def create_pwm_controllers():
     pwm_controllers = []
-    version = get_rpi_model()
+    version = get_rpi_version()
     if version is not None:
         logging.info(f'Device is Raspberry Pi {version}')
+        if not is_overlay_loaded():
+            logging.warning('PWM Overlay not loaded. Need to add \'dtoverlay=pwm-2chan\' to /boot/config.txt and reboot')
+            return []
         from .rpi_pwm_hardware import RPiHardwarePWMController
         if version == 5:
             pwm_controllers.append(RPiHardwarePWMController(chip=2, pins={
@@ -31,5 +53,5 @@ def create_pwm_controllers():
         else:
             pwm_controllers.append(RPiHardwarePWMController())
     else:
-        pwm_controllers.append(FakePWMController())
+        logging.info('No supported PWM Controllers Found.')
     return pwm_controllers