View difference between Paste ID: e6uQxa8J and xDGNHWt8

 -- Open rednet on the modem side (adjust "left" as needed)
 rednet.open("top")
 
-print("Waiting for coordinate broadcasts...")
+print("Waiting for coordinate broadcasts when redstone is active on the front...")
 
 while true do
-    local senderID, message, protocol = rednet.receive("coordBroadcast")
+    -- Only process messages when redstone signal on the "front" is on.
-
+    if redstone.getInput("front") then
-    if message and message.x and message.y and message.z then
+        -- Use a timeout (0.5 seconds) so the call doesn't block indefinitely and allows rechecking the redstone state.
-        print("Received coordinates from computer " .. senderID .. ":")
+        local senderID, message, protocol = rednet.receive("coordBroadcast", 0.5)
-        print("X: " .. message.x .. ", Y: " .. message.y .. ", Z: " .. message.z)
+
-        -- Add any further processing of the coordinates here
+        if senderID then
             if message and message.x and message.y and message.z then
-        print("Received invalid data from computer " .. senderID)
+                print("Received coordinates from computer " .. senderID .. ":")
                 print("X: " .. message.x .. ", Y: " .. message.y .. ", Z: " .. message.z)
             else
                 print("Received invalid data from computer " .. senderID)
             end
         end
     else
         -- Optionally, you can print a message when redstone is off or simply sleep quietly.
         -- print("Redstone is off on the front; not receiving messages.")
         sleep(0.1)
     end
 end