adding userpref option for decoupling the auto discovery channel from auto position updates

src/modules/NodeInfoModule.cpp

@@ -53,6 +53,12 @@ void NodeInfoModule::sendOurNodeInfo(NodeNum dest, bool wantReplies, uint8_t cha
             LOG_DEBUG("Send ourNodeInfo to channel %d", channel);
             p->channel = channel;
         }
+#ifdef USERPREFS_CONFIG_DISCOVERY_CHANNEL
+        // If this is a broadcast over the default channel, we can safely change this to the discovery channel if defined
+        if (dest === NODENUM_BROADCAST && channel === 0) {
+            p->channel = USERPREFS_CONFIG_DISCOVERY_CHANNEL;
+        }
+#endif
 
         prevPacketId = p->id;
 

src/modules/PositionModule.cpp

@@ -1,5 +1,6 @@
 #if !MESHTASTIC_EXCLUDE_GPS
 #include "PositionModule.h"
+#include "NodeInfoModule.h"
 #include "Default.h"
 #include "GPS.h"
 #include "MeshService.h"
@@ -315,6 +316,13 @@ void PositionModule::sendOurPosition()
     // If we changed channels, ask everyone else for their latest info
     LOG_INFO("Send pos@%x:6 to mesh (wantReplies=%d)", localPosition.timestamp, requestReplies);
     sendOurPosition(NODENUM_BROADCAST, requestReplies);
+
+#ifdef USERPREFS_CONFIG_DISCOVERY_CHANNEL
+    // If the user wants discovery on a different channel, send only nodeinfo to that channel
+    // sendOurNodeInfo() will automatically handle routing a nodeinfo packet to the correct channel
+    assert(nodeInfoModule);
+    nodeInfoModule->sendOurNodeInfo();
+#endif
 }
 
 void PositionModule::sendOurPosition(NodeNum dest, bool wantReplies, uint8_t channel)

userPrefs.jsonc

@@ -34,4 +34,5 @@
   // "USERPREFS_USE_ADMIN_KEY_0": "{ 0xcd, 0xc0, 0xb4, 0x3c, 0x53, 0x24, 0xdf, 0x13, 0xca, 0x5a, 0xa6, 0x0c, 0x0d, 0xec, 0x85, 0x5a, 0x4c, 0xf6, 0x1a, 0x96, 0x04, 0x1a, 0x3e, 0xfc, 0xbb, 0x8e, 0x33, 0x71, 0xe5, 0xfc, 0xff, 0x3c }",
   // "USERPREFS_USE_ADMIN_KEY_1": "{}",
   // "USERPREFS_USE_ADMIN_KEY_2": "{}"
+  // "USERPREFS_CONFIG_DISCOVERY_CHANNEL": "2"
 }