diff --git a/radio/util/hw_defs/generator.py b/radio/util/hw_defs/generator.py
index a9ba622bf..3c00857c7 100644
--- a/radio/util/hw_defs/generator.py
+++ b/radio/util/hw_defs/generator.py
@@ -1,10 +1,13 @@
 import json
+import os
+import sys
 import jinja2
+import pydantic
 
 import legacy_names
 import json_index
 
-from models import KeyEnum
+from models import HardwareDefinition, KeyEnum
 
 MAIN_CONTROL_LUT = {
     # 2 Gimbal radios
@@ -17,61 +20,83 @@ MAIN_CONTROL_LUT = {
     "TH": {"str": "TH", "local": "STR_SURFACE_NAMES1"},
 }
 
-# def eprint(*args, **kwargs):
-#     from sys import stderr
-#     print(*args, file=stderr, **kwargs)
+
+def eprint(*args, **kwargs):
+    print(*args, file=sys.stderr, **kwargs)
 
 
 def is_ext_input(input):
-    if input.get("type") != "FLEX":
+    if str(getattr(input, "type", "")) != "FLEX":
         return False
 
-    name = input.get("name")
-    if name and name.startswith("EXT"):
-        return True
-
-    return False
+    name = str(getattr(input, "name", ""))
+    return name.startswith("EXT")
 
 
 def generate_from_template(json_filename, template_filename, target):
     with open(json_filename) as json_file:
-        with open(template_filename) as template_file:
-            root_obj = json.load(json_file)
+        raw_data = json_file.read()
 
-            adc_inputs = root_obj.get("adc_inputs")
-            adc_index = json_index.build_adc_index(adc_inputs)
-            adc_gpios = json_index.build_adc_gpio_port_index(adc_inputs)
+        # Validate using Pydantic model
+        try:
+            hw_def = HardwareDefinition.from_json(raw_data)
+        except pydantic.ValidationError as e:
+            eprint(f"ERROR validating '{json_filename}' (target={target}):")
+            for err in e.errors():
+                loc = " -> ".join(str(l) for l in err["loc"])
+                eprint(f"  {loc}: {err['msg']}")
+            sys.exit(1)
 
-            switches = root_obj.get("switches")
-            switch_gpios = json_index.build_switch_gpio_port_index(switches)
+        # Load remaining fields not yet in the Pydantic model
+        root_obj = json.loads(raw_data)
 
-            keys = root_obj.get("keys")
-            key_gpios = json_index.build_key_gpio_port_index(keys)
+        adc_index = json_index.build_adc_index(hw_def.adc_inputs)
+        adc_gpios = json_index.build_adc_gpio_port_index(hw_def.adc_inputs)
+        switch_gpios = json_index.build_switch_gpio_port_index(hw_def.switches)
+        key_gpios = json_index.build_key_gpio_port_index(hw_def.keys)
 
-            trims = root_obj.get("trims")
-            trim_gpios = json_index.build_trim_gpio_port_index(trims)
+        trims = root_obj.get("trims")
+        trim_gpios = json_index.build_trim_gpio_port_index(trims)
 
-            legacy_inputs = legacy_names.inputs_by_target(target)
+        legacy_inputs = legacy_names.inputs_by_target(target)
 
-            env = jinja2.Environment(lstrip_blocks=True, trim_blocks=True)
+        template_dir = os.path.dirname(os.path.abspath(template_filename))
+        template_name = os.path.basename(template_filename)
 
-            env.tests["ext_input"] = is_ext_input
+        env = jinja2.Environment(
+            loader=jinja2.FileSystemLoader(template_dir),
+            lstrip_blocks=True,
+            trim_blocks=True,
+        )
 
-            template_str = template_file.read()
-            template = env.from_string(template_str)
+        env.tests["ext_input"] = is_ext_input
 
-            key_index = list([str(i) for i in KeyEnum])
+        template = env.get_template(template_name)
 
-            print(
-                template.render(
-                    root_obj,
-                    adc_index=adc_index,
-                    adc_gpios=adc_gpios,
-                    switch_gpios=switch_gpios,
-                    key_gpios=key_gpios,
-                    trim_gpios=trim_gpios,
-                    legacy_inputs=legacy_inputs,
-                    main_labels=MAIN_CONTROL_LUT,
-                    key_index=key_index,
-                )
-            )
+        key_index = list([str(i) for i in KeyEnum])
+
+        context = dict(
+            adc_inputs=hw_def.adc_inputs,
+            switches=hw_def.switches,
+            keys=hw_def.keys,
+            trims=trims,
+            adc_index=adc_index,
+            adc_gpios=adc_gpios,
+            switch_gpios=switch_gpios,
+            key_gpios=key_gpios,
+            trim_gpios=trim_gpios,
+            legacy_inputs=legacy_inputs,
+            main_labels=MAIN_CONTROL_LUT,
+            key_index=key_index,
+        )
+
+        try:
+            print(template.render(context))
+        except jinja2.UndefinedError as e:
+            eprint(f"ERROR rendering template '{template_name}'"
+                   f" with json='{json_filename}', target='{target}':")
+            eprint(f"  {e}")
+            none_keys = [k for k, v in context.items() if v is None]
+            if none_keys:
+                eprint(f"  None-valued context keys: {none_keys}")
+            sys.exit(1)
diff --git a/radio/util/hw_defs/json_index.py b/radio/util/hw_defs/json_index.py
index ccbcb8695..739aa3e7e 100644
--- a/radio/util/hw_defs/json_index.py
+++ b/radio/util/hw_defs/json_index.py
@@ -1,12 +1,11 @@
 #
-# These methods are used to build helper indexes on JSON structures
+# These methods are used to build helper indexes on data structures
 #
 def build_adc_index(adc_inputs):
     i = 0
     index = {}
-    for adc_input in adc_inputs["inputs"]:
-        name = adc_input["name"]
-        index[name] = i
+    for adc_input in adc_inputs.inputs:
+        index[str(adc_input.name)] = i
         i = i + 1
 
     return index
@@ -22,11 +21,11 @@ def append_to_index(d, key, val):
 def build_adc_gpio_port_index(adc_inputs):
     i = 0
     gpios = {}
-    for adc_input in adc_inputs["inputs"]:
-        if adc_input["adc"] == "SPI":
+    for adc_input in adc_inputs.inputs:
+        if str(adc_input.adc) == "SPI":
             continue
 
-        gpio = adc_input["gpio"]
+        gpio = getattr(adc_input, "gpio", None)
         if gpio is None:
             i = i + 1
             continue
@@ -34,7 +33,7 @@ def build_adc_gpio_port_index(adc_inputs):
         if gpio not in gpios:
             gpios[gpio] = []
 
-        pin = {"pin": adc_input["pin"], "idx": i}
+        pin = {"pin": adc_input.pin, "idx": i}
 
         gpios[gpio].append(pin)
         i = i + 1
@@ -45,22 +44,22 @@ def build_adc_gpio_port_index(adc_inputs):
 def build_switch_gpio_port_index(switches):
     gpios = {}
     for switch in switches:
-        sw_type = switch["type"]
+        sw_type = str(switch.type)
 
         if sw_type == "2POS" or sw_type == "FSWITCH":
-            gpio = switch.get("gpio")
-            pin = switch.get("pin")
+            gpio = switch.gpio
+            pin = switch.pin
             if gpio is not None and pin is not None:
                 append_to_index(gpios, gpio, pin)
 
         elif sw_type == "3POS":
-            gpio_high = switch.get("gpio_high")
-            pin_high = switch.get("pin_high")
+            gpio_high = switch.gpio_high
+            pin_high = switch.pin_high
             if gpio_high is not None and pin_high is not None:
                 append_to_index(gpios, gpio_high, pin_high)
 
-            gpio_low = switch.get("gpio_low")
-            pin_low = switch.get("pin_low")
+            gpio_low = switch.gpio_low
+            pin_low = switch.pin_low
             if gpio_low is not None and pin_low is not None:
                 append_to_index(gpios, gpio_low, pin_low)
 
@@ -88,6 +87,6 @@ def build_trim_gpio_port_index(trims):
 def build_key_gpio_port_index(keys):
     gpios = {}
     for key in keys:
-        append_to_index(gpios, key["gpio"], key["pin"])
+        append_to_index(gpios, key.gpio, key.pin)
 
-    return gpios
\ No newline at end of file
+    return gpios
diff --git a/radio/util/hw_defs/models.py b/radio/util/hw_defs/models.py
index 0210bb02f..02752b05b 100644
--- a/radio/util/hw_defs/models.py
+++ b/radio/util/hw_defs/models.py
@@ -26,6 +26,11 @@ class ADC(BaseModel):
     dma_stream: Optional[str] = None
     dma_stream_irq: Optional[str] = None
     dma_stream_irq_handler: Optional[str] = None
+    # SPI ADC fields
+    gpio_pin_sck: Optional[str] = None
+    gpio_pin_miso: Optional[str] = None
+    gpio_pin_mosi: Optional[str] = None
+    gpio_pin_cs: Optional[str] = None
 
 
 StickEnum = StrEnum(
@@ -75,6 +80,7 @@ InputType = StrEnum(
         "VBAT",
         "RTC_BAT",
         "RAW",
+        "LUX",
     ),
 )
 
@@ -100,6 +106,7 @@ class StickInput(BaseModel):
     pin: Optional[str] = None
     channel: Optional[Union[str, int]] = None
     inverted: Optional[bool] = False
+    pwm_channel: Optional[int] = None
 
 
 class FlexInput(BaseModel):
@@ -110,7 +117,7 @@ class FlexInput(BaseModel):
     pin: Optional[str] = None
     channel: Optional[Union[str, int]] = None
     inverted: Optional[bool] = False
-    default: Optional[FlexType] = FlexType.NONE
+    default: Optional[FlexType] = None
     label: Optional[str] = None
     short_label: Optional[str] = None
 
@@ -150,7 +157,16 @@ class RTCBatInput(BaseModel):
     channel: str
 
 
-Input = Union[StickInput, FlexInput, SwitchInput, RawInput, VBatInput, RTCBatInput]
+class LuxInput(BaseModel):
+    name: Literal["LUX"]
+    type: Literal["LUX"]
+    adc: ADCNameType
+    gpio: Optional[str] = None
+    pin: Optional[str] = None
+    channel: Optional[Union[str, int]] = None
+
+
+Input = Union[StickInput, FlexInput, SwitchInput, RawInput, VBatInput, RTCBatInput, LuxInput]
 
 
 class ADCInputs(BaseModel):
@@ -230,6 +246,8 @@ class Switch(BaseModel):
     default: Optional[SwitchTypeEnum] = SwitchTypeEnum.NONE
     flags: Optional[int] = 0
     inverted: Optional[bool] = False
+    is_cfs: Optional[bool] = False
+    cfs_idx: Optional[int] = None
     adc_input: Optional[str] = None
     gpio: Optional[str] = None
     pin: Optional[str] = None
diff --git a/radio/util/hw_defs/stm32_pwm_inputs.jinja b/radio/util/hw_defs/stm32_pwm_inputs.jinja
index f2fcfd177..a79525240 100644
--- a/radio/util/hw_defs/stm32_pwm_inputs.jinja
+++ b/radio/util/hw_defs/stm32_pwm_inputs.jinja
@@ -3,7 +3,7 @@
 //   This file has been generated from the target's JSON hardware description
 //
 
-{% set pwm_inputs = adc_inputs.inputs | selectattr('pwm_channel', 'defined') | list %}
+{% set pwm_inputs = adc_inputs.inputs | selectattr('type', '==', 'STICK') | selectattr('pwm_channel', 'ne', none) | list %}
 static const stick_pwm_input_t _PWM_inputs[] = {
 {% for input in pwm_inputs %}
   {