Debugging Source Code

Here is some source code for Arduino which allows you to stream to the Serial console detailed Hex and Binary data blobs.

Useful for debugging your message building.

Copy and paste the below into a file named UtlStreamBlob.cpp

#include <ctype.h>

#include <stdio.h>

#include <string.h>

#include "UtlStreamBlob.h"

// Original author: Douglas Malnati

void StreamBlob(Print    &stream,

                uint8_t  *buf,

                uint16_t  bufSize,

                uint8_t   showBin,

                uint8_t   showHex)

{

    char bufSprintf[9];

    uint16_t bufSizeRemaining = bufSize;

    uint16_t byteCount        = 0;

    while (bufSizeRemaining)

    {

        sprintf(bufSprintf, "%08X", byteCount);

        // Print byte start

        stream.print("0x");

        stream.print(bufSprintf);

        stream.print(": ");

        // Calculate how many real vs pad bytes to output

        uint8_t realBytes = (byteCount + 8 > bufSize) ?

                            (bufSize - byteCount)     :

                            8;

        uint8_t padBytes = 8 - realBytes;

        // Print hex

        if (showHex)

        {

            for (uint8_t i = 0; i < realBytes; ++i)

            {

                uint8_t b = buf[byteCount + i];

                sprintf(bufSprintf, "%02X", b);

                stream.print(bufSprintf);

                stream.print(" ");

            }

            for (uint8_t i = 0; i < padBytes; ++i)

            {

                stream.print("   ");

            }

            stream.print("| ");

        }

        // Print binary

        if (showBin)

        {

            for (uint8_t i = 0; i < realBytes; ++i)

            {

                uint8_t b = buf[byteCount + i];

                for (uint8_t j = 0; j < 8; ++j)

                {

                    stream.print((b & 0x80) ? 1 : 0);

                    b <<= 1;

                }

                stream.print(" ");

            }

            for (uint8_t i = 0; i < padBytes; ++i)

            {

                stream.print("         ");

            }

            stream.print("| ");

        }

        // Print visible

        for (uint8_t i = 0; i < realBytes; ++i)

        {

            uint8_t b = buf[byteCount + i];

            if (isprint(b))

            {

                stream.write(b);

            }

            else

            {

                stream.print('.');

            }

        }

        stream.println();

        // Account for used data

        byteCount += realBytes;

        bufSizeRemaining -= realBytes;

    }

}

Here is an example of code using this code:

void MakeAPRSMessage()

{

    // ...

    // all the code used to build the AX25UIMessage...

    // ...

    uint8_t bytesUsed = msg.Finalize();

    Serial.print("Message finalized, ");

    Serial.print(bytesUsed);

    Serial.print(" bytes used");

    Serial.println();

    uint8_t showBin = 1;

    uint8_t showHex = 1;

    StreamBlob(Serial, buf, bytesUsed, showBin, showHex);

    Serial.println();

    // Just an example, you'll have to write Send yourself

    Send(buf, bytesUsed);

}