1 #include <stdio.h>
2 #include <pb_encode.h>
3 #include <pb_decode.h>
4 #include "simple.pb.h"
5 
6 int main()
7 {
8     /* This is the buffer where we will store our message. */
9     uint8_t buffer[128];
10     size_t message_length;
11     bool status;
12 
13     /* Encode our message */
14     {
15         /* Allocate space on the stack to store the message data.
16          *
17          * Nanopb generates simple struct definitions for all the messages.
18          * - check out the contents of simple.pb.h!
19          * It is a good idea to always initialize your structures
20          * so that you do not have garbage data from RAM in there.
21          */
22         SimpleMessage message = SimpleMessage_init_zero;
23 
24         /* Create a stream that will write to our buffer. */
25         pb_ostream_t stream = pb_ostream_from_buffer(buffer, sizeof(buffer));
26 
27         /* Fill in the lucky number */
28         message.lucky_number = 13;
29 
30         /* Now we are ready to encode the message! */
31         status = pb_encode(&stream, SimpleMessage_fields, &message);
32         message_length = stream.bytes_written;
33 
34         /* Then just check for any errors.. */
35         if (!status)
36         {
37             printf("Encoding failed: %s\n", PB_GET_ERROR(&stream));
38             return 1;
39         }
40     }
41 
42     /* Now we could transmit the message over network, store it in a file or
43      * wrap it to a pigeon's leg.
44      */
45 
46     /* But because we are lazy, we will just decode it immediately. */
47 
48     {
49         /* Allocate space for the decoded message. */
50         SimpleMessage message = SimpleMessage_init_zero;
51 
52         /* Create a stream that reads from the buffer. */
53         pb_istream_t stream = pb_istream_from_buffer(buffer, message_length);
54 
55         /* Now we are ready to decode the message. */
56         status = pb_decode(&stream, SimpleMessage_fields, &message);
57 
58         /* Check for errors... */
59         if (!status)
60         {
61             printf("Decoding failed: %s\n", PB_GET_ERROR(&stream));
62             return 1;
63         }
64 
65         /* Print the data contained in the message. */
66         printf("Your lucky number was %d!\n", message.lucky_number);
67     }
68 
69     return 0;
70 }
71 
72