mesh.checkConnection via parent not master

.github/workflows/build_arduino.yml

@@ -6,6 +6,8 @@ on:
     paths:
       - ".github/workflows/build_arduino.yml"
       - "examples/**"
+      - "RF24Mesh.*"
+      - "RF24Mesh_config.h"
 
   push:
     branches: [master, v1.x]

RF24Mesh.cpp

@@ -154,8 +154,25 @@ void ESBMesh<network_t, radio_t>::setChild(bool allow)
 template<class network_t, class radio_t>
 bool ESBMesh<network_t, radio_t>::checkConnection()
 {
-    // getAddress() doesn't use auto-ack; do a double-check to manually retry 1 more time
-    for (uint8_t i = 0; i < MESH_CONNECTION_CHECK_ATTEMPTS; i++) {
+
+    if (!_nodeID) return false;
+    if (mesh_address == MESH_DEFAULT_ADDRESS) return false;
+
+// Connection check via parent node
+#if RF24MESH_CONN_CHECK_TYPE == RF24MESH_CONN_CHECK_PARENT
+    RF24NetworkHeader header;
+    header.to_node = network.parent();
+    header.type = NETWORK_PING;
+    for (uint8_t i = 0; i < MESH_CONNECTION_CHECK_ATTEMPTS; ++i) {
+        if (network.write(header, 0, 0)) {
+            return true;
+        }
+    }
+    return false;
+
+#else // Connection check via master node
+    // getAddress() doesn't use auto-ack; check connectivity multiple times
+    for (uint8_t i = 0; i < MESH_CONNECTION_CHECK_ATTEMPTS; ++i) {
 
         int16_t result = getAddress(_nodeID);
         switch (result) {
@@ -170,6 +187,7 @@ bool ESBMesh<network_t, radio_t>::checkConnection()
         }
     }
     return false;
+#endif
 }
 
 /*****************************************************/

RF24Mesh.h

@@ -190,7 +190,9 @@ class ESBMesh
     /**
      * Tests connectivity of this node to the mesh.
      * @note If this function fails, address renewal should typically be done.
-     * @return 1 if connected, 0 if mesh not responding
+     * @return 
+     * - True if connected.
+     * - False if not connected, mesh is not responding, or this node is the master node.
      */
     bool checkConnection();
 

RF24Mesh_config.h

@@ -64,6 +64,25 @@
     #define MESH_CONNECTION_CHECK_ATTEMPTS 3
 #endif
 
+#define RF24MESH_CONN_CHECK_PARENT 1
+#define RF24MESH_CONN_CHECK_MASTER 0
+/**
+ * @brief How to verify a connection
+ *
+ * On child nodes, determine how they verify/check their connection periodically, or when writes start to fail via the `RF24Mesh::checkConnection();`
+ * function.
+ * Set RF24MESH_CONN_CHECK_TYPE to @ref RF24MESH_CONN_CHECK_PARENT for the new behaviour of verifying connectivity only with their parent node.
+ * Set RF24MESH_CONN_CHECK_TYPE to @ref RF24MESH_CONN_CHECK_MASTER for the old behaviour of verifying connectivity with the master node.
+ * The old behaviour typically results in more network congestion, more load on the master node, and less reliable networks,
+ * but it can work well when radio conditions are good and/or when there are only a small number of nodes on the network and/or in close proximity
+ * to the master node.
+ */
+#ifndef RF24MESH_CONN_CHECK_TYPE
+    #define RF24MESH_CONN_CHECK_TYPE RF24MESH_CONN_CHECK_PARENT
+    // To use old behavior:
+    // #define RF24MESH_CONN_CHECK_TYPE RF24MESH_CONN_CHECK_MASTER
+#endif
+
 /**************************/
 /***       Debug        ***/
 //#define RF24MESH_DEBUG_MINIMAL /** Uncomment for the Master Node to print out address assignments as they are assigned */