Nanopb -Decoding failed: zero tag

Question

This is my first time writing here so excuse me if i did sometihing wrong.

I need help with "Decoding failed: zero tag" status.

I want to send array using ESP-NOW Here is my encoding side:

epostavke.baterija[0]=razina_baterije[0];
    postavke.baterija[1]=razina_baterije[1];
     postavke.baterija[2]=razina_baterije[2];
      postavke.baterija[03]=razina_baterije[3]; 
      postavke.baterija[4]=razina_baterije[4];
       postavke.baterija[5]=razina_baterije[5];
    pb_ostream_t stream = pb_ostream_from_buffer(buffer, sizeof(buffer));
    pb_encode(&stream, Postavke_fields, &postavke);
    esp_now_send(NULL, (uint8_t *) &buffer, sizeof(buffer));

and after encoding when I print :

 Serial.println(postavke.baterija[0]);
   Serial.println(postavke.baterija[1]);

it shows me right values - so it means that postavke.baterija[0] has value like postavke.baterija[1] , as example it shows me 87 ,85 it depends.

But problem is when I want to decode it. It shows me :"Decoding failed: zero tag" Here is code:

 enter cod stream = pb_istream_from_buffer(buffer,sizeof(buffer));
     bool status = pb_decode(&stream, Postavke_fields, &postavke);
        if (!status)
        {
            printf("Decoding failed: %s\n", PB_GET_ERROR(&stream));
            return ;
        }
     Serial.println("Stigli podaci, a oni glase: ");
     Serial.println(postavke.znak);
   Serial.println(postavke.vrijeme_trajanja);
   Serial.println(postavke.vrijeme_odmora);
   Serial.println(postavke.boja1);
   Serial.println(postavke.boja2);
   Serial.println(postavke.boja3);
   Serial.println(postavke.broj_signala);
   Serial.println(postavke.timer);
   Serial.println(postavke.multicaster);
   Serial.println(postavke.broj_propustenih);
   Serial.println(postavke.random_odmor);
  Serial.println(postavke.baterija[0]);
  Serial.println(postavke.baterija[1]);

If i dont use this

`

if (!status)

     {
            printf("Decoding failed: %s\n", PB_GET_ERROR(&stream));
            return ;
        }

It decodes everything else but not `"postavke.baterija" array

Here is how I did it in .proto file

 message Postavke {
required int32 ID=1;
required int32 znak=2;
required int32 vrijeme_trajanja=3;
required int32 vrijeme_odmora=4;
required int32 boja1=5;
required int32 boja2=6;
required int32 boja3=7;
required int32 broj_signala=8;
required int32 timer=9;
required int32 multicaster=10;
required int32 broj_propustenih=11;
required int32 random_odmor=12;
required int32 svjetlina=13;
 repeated int32  baterija=14 ;

}

and here is my .options file

Postavke.baterija  max_count:6;
Postavke.baterija  max_size:6;

Please help me!! Where is mistake? Why doenst want to decode?

Thank you!

score 3 · Answer 1 · answered Mar 20 '20 at 05:15

pb_istream_from_buffer(buffer,sizeof(buffer));

You need to pass the actual length of your message, instead of the whole length of the buffer.

Now nanopb is reading past the message length, and apparently hitting a zero tag number, which is not valid in Protocol Buffers.

Nanopb -Decoding failed: zero tag

1 Answers1