about ACK ...

[zzz-teo]

Hi, all
I am trying to build a simple project of two nodes.One node with a push button(TOGGLE) and one switch, both with feedback LEDs.The other node with two relays and local control buttons.
Its mandatory to have a reliable feedback to first node LEDs so, trying to figure out how ACK work in mysensors and how to resend the message if not ACK, I used
this...

 //function to handle the ACK .
#define ATTEMPTS 5

void SendData(byte sensor, byte destination, bool value, bool ack) {
         msg.setSensor(sensor);
         msg.setDestination(destination);
         
  for(byte i=0; i<=ATTEMPTS; i++){
      if(send(msg.set((bool)value),ack)){
         Serial.println("ACK");
         break;
        }else{
        Serial.println("NACK");
        }
    
        }
}

... which works great but only until the message reaches the gateway, not the target node! although I can see the ACK back from the target node it remains unparsed!
Can anyone give me an example of how to do it?

[zzz-teo]

... this approach seems that work !

#define ACKDELAY 40 //seems 40 millis is a good value
bool nodeACK = false;  
void SendData(byte sensor, byte destination, bool value, bool ack) {
         msg.setSensor(sensor);
         msg.setDestination(destination);
         
  for(byte i=0; i<=ATTEMPTS; i++){
      if(send(msg.set(value),ack)){
         Serial.println("Gateway ACK");
//         wait(ACKDELAY);
         if(nodeACK == true){
         Serial.println("Node ACK");
         nodeACK = false;
         break;}else{
         Serial.println("Node NACK");
         }
        }else{
        Serial.println("Gateway NACK");
        }
        wait(ACKDELAY);
        }
}

... in combination with this

void receive(const MyMessage &message) {
if (message.isAck()){
        nodeACK=true;
        digitalWrite(LED_PINS[message.sensor], message.getBool()? LED_ON:LED_OFF);
        Serial.println(F("ACK recieved LED Status Changed")); 
}

... but probably is not the most elegand way!
... because if during the send/ack back message duty cycle, an ack from an other sensor received, a conflict may occure! i do not feel safe!
(i also have a feeling that i did that post in the wrong topic! )