update

src/communication.jl

@@ -80,6 +80,7 @@ mutable struct mqttClientInstance_v2 <: mqttClientInstance
   keepaliveCheckInterval::Integer   # second
   lastTimeMqttConnCheck::Union{DateTime, Nothing}
   multiMsg::String  # "single", "metadata", "datapart"
+  latestMsg
 end
 """ MQTT client v2. The difference between client v1 and v2 is v2 allows multiple 
   msgReceiveChannel without having to redefine mqttClientInstance again like in v1.
@@ -178,6 +179,7 @@ function mqttClientInstance_v2(
     keepaliveCheckInterval,
     nothing,
     multiMsg,
+    nothing,  # store latest message to prevent doing the same massage twice
   )
 
   return instance