Space out periodic broadcasts of modules automatically (#5931)

* Space out periodic broadcasts of modules automatically

* Add warning for function usage

---------

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

src/mesh/MeshModule.cpp

@@ -10,6 +10,7 @@
 std::vector<MeshModule *> *MeshModule::modules;
 
 const meshtastic_MeshPacket *MeshModule::currentRequest;
+uint8_t MeshModule::numPeriodicModules = 0;
 
 /**
  * If any of the current chain of modules has already sent a reply, it will be here.  This is useful to allow
@@ -35,6 +36,15 @@ MeshModule::~MeshModule()
     modules->erase(it);
 }
 
+// ⚠️ **Only call once** to set the initial delay before a module starts broadcasting periodically
+int32_t MeshModule::setStartDelay()
+{
+    int32_t startDelay = MESHMODULE_MIN_BROADCAST_DELAY_MS + numPeriodicModules * MESHMODULE_BROADCAST_SPACING_MS;
+    numPeriodicModules++;
+
+    return startDelay;
+}
+
 meshtastic_MeshPacket *MeshModule::allocAckNak(meshtastic_Routing_Error err, NodeNum to, PacketId idFrom, ChannelIndex chIndex,
                                                uint8_t hopLimit)
 {

src/mesh/MeshModule.h

@@ -9,6 +9,9 @@
 #include <OLEDDisplayUi.h>
 #endif
 
+#define MESHMODULE_MIN_BROADCAST_DELAY_MS 30 * 1000 // Min. delay after boot before sending first broadcast by any module
+#define MESHMODULE_BROADCAST_SPACING_MS 15 * 1000   // Initial spacing between broadcasts of different modules
+
 /** handleReceived return enumeration
  *
  * Use ProcessMessage::CONTINUE to allows other modules to process a message.
@@ -119,6 +122,12 @@ class MeshModule
      */
     static const meshtastic_MeshPacket *currentRequest;
 
+    // We keep track of the number of modules that send a periodic broadcast to schedule them spaced out over time
+    static uint8_t numPeriodicModules;
+
+    // Set the start delay for module that broadcasts periodically
+    int32_t setStartDelay();
+
     /**
      * If your handler wants to send a response, simply set currentReply and it will be sent at the end of response handling.
      */