meshtastic · NomDeTom · Aug 28, 2026 · Aug 28, 2026 · Aug 28, 2026 · Aug 28, 2026
diff --git a/.gitmodules b/.gitmodules
@@ -1,6 +1,7 @@
 [submodule "protobufs"]
 	path = protobufs
-	url = https://github.com/meshtastic/protobufs.git
+	url = https://github.com/NomDeTom/Meshtasticprotobufs
+	branch = beacon-frequency-slot
 [submodule "meshtestic"]
 	path = meshtestic
 	url = https://github.com/meshtastic/meshTestic
diff --git a/protobufs b/protobufs
diff --git a/src/graphics/draw/MenuHandler.cpp b/src/graphics/draw/MenuHandler.cpp
@@ -497,29 +497,12 @@ void menuHandler::FrequencySlotPicker()
     optionsArray[options] = "Slot 0 (Auto)";
     optionsEnumArray[options++] = 0;
 
-    // Calculate number of channels (copied from RadioInterface::applyModemConfig())
-
-    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) {
-        // 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 * 2) + channelBandwidthMHz;
-        if (denominator > 0.0) {
-            numChannels = static_cast<uint32_t>(round(numerator / denominator));
-        } else {
-            LOG_WARN("Invalid region config: non-positive channel spacing/width");
-        }
-    } else {
+    if (!myRegion) {
         LOG_WARN("Region not set, can't calc channel count");
         return;
     }
+    // The count the radio will actually run on, rather than a fourth copy of the arithmetic.
+    uint32_t numChannels = RadioInterface::frequencySlotCount(config.lora);
 
     if (numChannels > (uint32_t)(MAX_CHANNEL_OPTIONS - 2))
         numChannels = (uint32_t)(MAX_CHANNEL_OPTIONS - 2);

diff --git a/src/mesh/NodeDB.cpp b/src/mesh/NodeDB.cpp
@@ -30,6 +30,9 @@
 #include "mesh-pb-constants.h"
 #include "mesh/generated/meshtastic/deviceonly_legacy.pb.h"
 #include "meshUtils.h"
+#if !MESHTASTIC_EXCLUDE_BEACON
+#include "modules/MeshBeaconModule.h"
+#endif
 #include "modules/NeighborInfoModule.h"
 #include "target_specific.h"
 #if HAS_VARIABLE_HOPS
@@ -817,6 +820,13 @@ void NodeDB::resetRadioConfig(bool is_fresh_install)
 
     // Update the global myRegion
     initRegion();
+
+#if !MESHTASTIC_EXCLUDE_BEACON
+    // A userPrefs build writes broadcast targets and the offer straight into moduleConfig, so this
+    // is the only point that catches a combination no radio can key up on. Channels are live above.
+    if (moduleConfig.has_mesh_beacon)
+        MeshBeaconModule::sanitiseConfig(moduleConfig.mesh_beacon);
+#endif
 }
 
 bool NodeDB::factoryReset(bool eraseBleBonds)
@@ -1499,20 +1509,19 @@ void NodeDB::installDefaultModuleConfig()
 #ifdef USERPREFS_MESH_BEACON_OFFER_REGION
     moduleConfig.mesh_beacon.broadcast_offer_region = USERPREFS_MESH_BEACON_OFFER_REGION;
 #endif
-#ifdef USERPREFS_MESH_BEACON_OFFER_CHANNEL_NAME
-    moduleConfig.mesh_beacon.has_broadcast_offer_channel = true;
-    strncpy(moduleConfig.mesh_beacon.broadcast_offer_channel.name, USERPREFS_MESH_BEACON_OFFER_CHANNEL_NAME,
-            sizeof(moduleConfig.mesh_beacon.broadcast_offer_channel.name) - 1);
-    moduleConfig.mesh_beacon.broadcast_offer_channel.name[sizeof(moduleConfig.mesh_beacon.broadcast_offer_channel.name) - 1] =
-        '\0';
-#endif
-#ifdef USERPREFS_MESH_BEACON_OFFER_CHANNEL_PSK
-    moduleConfig.mesh_beacon.has_broadcast_offer_channel = true;
-    static const uint8_t beaconOfferPsk[] = USERPREFS_MESH_BEACON_OFFER_CHANNEL_PSK;
-    static_assert(sizeof(beaconOfferPsk) <= sizeof(moduleConfig.mesh_beacon.broadcast_offer_channel.psk.bytes),
-                  "USERPREFS_MESH_BEACON_OFFER_CHANNEL_PSK exceeds the 32-byte channel PSK buffer");
-    memcpy(moduleConfig.mesh_beacon.broadcast_offer_channel.psk.bytes, beaconOfferPsk, sizeof(beaconOfferPsk));
-    moduleConfig.mesh_beacon.broadcast_offer_channel.psk.size = sizeof(beaconOfferPsk);
+#ifdef USERPREFS_MESH_BEACON_OFFER_CHANNEL_INDEX
+    moduleConfig.mesh_beacon.has_broadcast_offer_channel_index = true;
+    moduleConfig.mesh_beacon.broadcast_offer_channel_index = USERPREFS_MESH_BEACON_OFFER_CHANNEL_INDEX;
+#endif
+#ifdef USERPREFS_MESH_BEACON_OFFER_FREQUENCY_SLOT
+    moduleConfig.mesh_beacon.has_broadcast_offer_frequency_slot = true;
+    moduleConfig.mesh_beacon.broadcast_offer_frequency_slot = USERPREFS_MESH_BEACON_OFFER_FREQUENCY_SLOT;
+#endif
+// The offer channel is now a slot in the device's channel table rather than an inline name and
+// PSK, so an integrator provisions the channel and points at it.
+#if defined(USERPREFS_MESH_BEACON_OFFER_CHANNEL_NAME) || defined(USERPREFS_MESH_BEACON_OFFER_CHANNEL_PSK)
+#error                                                                                                                           \
+    "USERPREFS_MESH_BEACON_OFFER_CHANNEL_{NAME,PSK} removed; provision the channel and use USERPREFS_MESH_BEACON_OFFER_CHANNEL_INDEX"
 #endif
 // The USERPREFS_MESH_BEACON_ON_* keys were removed with the broadcast_on_* config fields. Fail the
 // build rather than silently dropping a preconfigured beacon channel: define the equivalent
@@ -1549,6 +1558,14 @@ void NodeDB::installDefaultModuleConfig()
         moduleConfig.mesh_beacon.broadcast_targets[(N)].has_channel_index = true;                                                \
         moduleConfig.mesh_beacon.broadcast_targets[(N)].channel_index = (VAL);                                                   \
     } while (0)
+// A pinned frequency slot is 1-based, matching Config.LoRaConfig.channel_num.
+#define BEACON_TARGET_FREQ_SLOT(N, VAL)                                                                                          \
+    do {                                                                                                                         \
+        if (moduleConfig.mesh_beacon.broadcast_targets_count < (N) + 1)                                                          \
+            moduleConfig.mesh_beacon.broadcast_targets_count = (N) + 1;                                                          \
+        moduleConfig.mesh_beacon.broadcast_targets[(N)].has_frequency_slot = true;                                               \
+        moduleConfig.mesh_beacon.broadcast_targets[(N)].frequency_slot = (VAL);                                                  \
+    } while (0)
 #ifdef USERPREFS_MESH_BEACON_TARGET_0_PRESET
     BEACON_TARGET_PRESET(0, USERPREFS_MESH_BEACON_TARGET_0_PRESET);
 #endif
@@ -1558,6 +1575,9 @@ void NodeDB::installDefaultModuleConfig()
 #ifdef USERPREFS_MESH_BEACON_TARGET_0_CHANNEL_INDEX
     BEACON_TARGET_CH_INDEX(0, USERPREFS_MESH_BEACON_TARGET_0_CHANNEL_INDEX);
 #endif
+#ifdef USERPREFS_MESH_BEACON_TARGET_0_FREQUENCY_SLOT
+    BEACON_TARGET_FREQ_SLOT(0, USERPREFS_MESH_BEACON_TARGET_0_FREQUENCY_SLOT);
+#endif
 #ifdef USERPREFS_MESH_BEACON_TARGET_1_PRESET
     BEACON_TARGET_PRESET(1, USERPREFS_MESH_BEACON_TARGET_1_PRESET);
 #endif
@@ -1567,6 +1587,9 @@ void NodeDB::installDefaultModuleConfig()
 #ifdef USERPREFS_MESH_BEACON_TARGET_1_CHANNEL_INDEX
     BEACON_TARGET_CH_INDEX(1, USERPREFS_MESH_BEACON_TARGET_1_CHANNEL_INDEX);
 #endif
+#ifdef USERPREFS_MESH_BEACON_TARGET_1_FREQUENCY_SLOT
+    BEACON_TARGET_FREQ_SLOT(1, USERPREFS_MESH_BEACON_TARGET_1_FREQUENCY_SLOT);
+#endif
 #ifdef USERPREFS_MESH_BEACON_TARGET_2_PRESET
     BEACON_TARGET_PRESET(2, USERPREFS_MESH_BEACON_TARGET_2_PRESET);
 #endif
@@ -1576,6 +1599,9 @@ void NodeDB::installDefaultModuleConfig()
 #ifdef USERPREFS_MESH_BEACON_TARGET_2_CHANNEL_INDEX
     BEACON_TARGET_CH_INDEX(2, USERPREFS_MESH_BEACON_TARGET_2_CHANNEL_INDEX);
 #endif
+#ifdef USERPREFS_MESH_BEACON_TARGET_2_FREQUENCY_SLOT
+    BEACON_TARGET_FREQ_SLOT(2, USERPREFS_MESH_BEACON_TARGET_2_FREQUENCY_SLOT);
+#endif
 #ifdef USERPREFS_MESH_BEACON_TARGET_3_PRESET
     BEACON_TARGET_PRESET(3, USERPREFS_MESH_BEACON_TARGET_3_PRESET);
 #endif
@@ -1585,9 +1611,13 @@ void NodeDB::installDefaultModuleConfig()
 #ifdef USERPREFS_MESH_BEACON_TARGET_3_CHANNEL_INDEX
     BEACON_TARGET_CH_INDEX(3, USERPREFS_MESH_BEACON_TARGET_3_CHANNEL_INDEX);
 #endif
+#ifdef USERPREFS_MESH_BEACON_TARGET_3_FREQUENCY_SLOT
+    BEACON_TARGET_FREQ_SLOT(3, USERPREFS_MESH_BEACON_TARGET_3_FREQUENCY_SLOT);
+#endif
 #undef BEACON_TARGET_PRESET
 #undef BEACON_TARGET_REGION
 #undef BEACON_TARGET_CH_INDEX
+#undef BEACON_TARGET_FREQ_SLOT
 #endif // !MESHTASTIC_EXCLUDE_BEACON
 
     initModuleConfigIntervals();

diff --git a/src/mesh/PhoneAPI.cpp b/src/mesh/PhoneAPI.cpp
@@ -919,10 +919,8 @@ size_t PhoneAPI::getFromRadio(uint8_t *buf)
             fromRadioScratch.moduleConfig.which_payload_variant = meshtastic_ModuleConfig_mesh_beacon_tag;
 #ifdef MESHTASTIC_PHONEAPI_ACCESS_CONTROL
             if (!getAdminAuthorized()) {
-                // Unauthenticated: emit an empty MeshBeaconConfig (zero-init from
-                // the top-of-loop memset). The embedded broadcast_offer_channel
-                // ChannelSettings carries a PSK that must not be visible to an
-                // unauth client.
+                // Unauthenticated: emit an empty MeshBeaconConfig (zero-init from the top-of-loop
+                // memset). No PSK now, but it still names the message and the advertised slots.
             } else
 #endif
             {
+11 −0		meshtastic/mesh_beacon.proto
+0 −2		meshtastic/module_config.options
+35 −6		meshtastic/module_config.proto