Lora settings expansion and validation logic improvement

src/graphics/draw/MenuHandler.cpp

@@ -25,6 +25,7 @@
 #include "modules/TraceRouteModule.h"
 #include <algorithm>
 #include <array>
+#include <cmath>
 #include <functional>
 #include <utility>
 
@@ -265,13 +266,28 @@ void menuHandler::FrequencySlotPicker()
     optionsEnumArray[options++] = 0;
 
     // Calculate number of channels (copied from RadioInterface::applyModemConfig())
+    if (!myRegion) {
+        LOG_WARN("Region not set, cannot calculate number of channels");
+        return;
+    }
+
     meshtastic_Config_LoRaConfig &loraConfig = config.lora;
     double bw = loraConfig.use_preset ? modemPresetToBwKHz(loraConfig.modem_preset, myRegion->wideLora)
                                       : bwCodeToKHz(loraConfig.bandwidth);
 
     uint32_t numChannels = 0;
     if (myRegion) {
-        numChannels = (uint32_t)floor((myRegion->freqEnd - myRegion->freqStart) / (myRegion->spacing + (bw / 1000.0)));
+        // Match RadioInterface::applyModemConfig(): include padding, add spacing in numerator, and use round()
+        const double spacing = myRegion->profile->spacing;
+        const double padding = myRegion->profile->padding;
+        const double channelBandwidthMHz = bw / 1000.0;
+        const double numerator = (myRegion->freqEnd - myRegion->freqStart) + spacing;
+        const double denominator = spacing + padding + channelBandwidthMHz;
+        if (denominator > 0.0) {
+            numChannels = static_cast<uint32_t>(std::round(numerator / denominator));
+        } else {
+            LOG_WARN("Invalid region configuration: non-positive channel spacing/width");
+        }
     } else {
         LOG_WARN("Region not set, cannot calculate number of channels");
         return;

src/mesh/MeshRadio.h

@@ -5,18 +5,51 @@
 #include "PointerQueue.h"
 #include "configuration.h"
 
+// Sentinel marking the end of a modem preset array
+#define MODEM_PRESET_END ((meshtastic_Config_LoRaConfig_ModemPreset)0xFF)
+
+// Region profile: bundles the preset list with regulatory parameters shared across regions
+struct RegionProfile {
+    const meshtastic_Config_LoRaConfig_ModemPreset *presets; // sentinel-terminated; first entry is the default
+    float spacing;                                           // gaps between radio channels
+    float padding;                                           // padding at each side of the "operating channel"
+    bool audioPermitted;
+    bool licensedOnly;        // a region profile for licensed operators only
+    int8_t textThrottle;      // throttle for text - future expansion
+    int8_t positionThrottle;  // throttle for location data - future expansion
+    int8_t telemetryThrottle; // throttle for telemetry - future expansion
+    uint8_t overrideSlot;     // a per-region override slot for if we need to fix it in place
+};
+
+extern const RegionProfile PROFILE_STD;
+extern const RegionProfile PROFILE_EU868;
+extern const RegionProfile PROFILE_UNDEF;
+// extern const RegionProfile  PROFILE_LITE;
+// extern const RegionProfile  PROFILE_NARROW;
+// extern const RegionProfile  PROFILE_HAM;
+
 // Map from old region names to new region enums
 struct RegionInfo {
     meshtastic_Config_LoRaConfig_RegionCode code;
     float freqStart;
     float freqEnd;
-    float dutyCycle;
-    float spacing;
+    float dutyCycle;    // modified by getEffectiveDutyCycle
     uint8_t powerLimit; // Or zero for not set
-    bool audioPermitted;
     bool freqSwitching;
     bool wideLora;
+    const RegionProfile *profile;
     const char *name; // EU433 etc
+
+    // Preset accessors (delegate through profile)
+    meshtastic_Config_LoRaConfig_ModemPreset getDefaultPreset() const { return profile->presets[0]; }
+    const meshtastic_Config_LoRaConfig_ModemPreset *getAvailablePresets() const { return profile->presets; }
+    size_t getNumPresets() const
+    {
+        size_t n = 0;
+        while (profile->presets[n] != MODEM_PRESET_END)
+            n++;
+        return n;
+    }
 };
 
 extern const RegionInfo regions[];

src/mesh/NodeDB.cpp

@@ -1299,7 +1299,7 @@ void NodeDB::loadFromDisk()
     // Coerce LoRa config fields derived from presets while bootstrapping.
     // Some clients/UI components display bandwidth/spread_factor directly from config even in preset mode.
     if (config.has_lora && config.lora.use_preset) {
-        RadioInterface::bootstrapLoRaConfigFromPreset(config.lora);
+        RadioInterface::clampConfigLora(config.lora);
     }
 
 #if defined(USERPREFS_LORA_TX_DISABLED) && USERPREFS_LORA_TX_DISABLED