LoRa byte output to TinyGPS [solution]

[MLH]

I have an application where I would like to feed byte data from the LoRa to TinyGPS++.  I'm having difficulty adapting the code which outputs in string format.

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void getRadio()
{
  if (rf95.available())
    buf[RH_RF95_MAX_MESSAGE_LEN];
  byte len = sizeof(buf);
  if (rf95.recv(buff, &len))
  {
    Serial.print((char*)buff);
}

Thanks,

Mike

[LukaQ]

I won't be able to help much, but you have buff and buf. That also can be right, just don't know
why don't you use one of the sketch, that sends string? I think it is Node.ino

[MLH]

TinyGPS++ accepts data one byte at a time, it cannot be fed a string.

[Felix]

The radio is giving you a string (byte array). So you can traverse the byte array one char (ascii byte) at a time and delegate it as needed. I think that's what you need.

Code Select Expand

for (byte i=0; i<len ; i++)
   tinyGps : eat some buff[i];

[MLH]

Felix,

I was for the most part there, just needed a nudge in the right direction. The second line of code was the key " tinyGps : eat some buff;".

Here's the working code I ended up with:

Code Select Expand

void loop()
{
  if (rf95.available())
    buf[RH_RF95_MAX_MESSAGE_LEN];
  byte len = sizeof(buf);
  if (rf95.recv(buff, &len))
  {
    Serial.println((char*)buff);    //send to COM port 4800 baud
    for (int i = 0; i < len ; i++)
    {
      buff[i];
      if (gps.encode(buff[i]))  // <--- now pass it to TinyGPS
      {
        index = 0;
        if (gps.location.isValid())
        {
          Serial1.print(F("Location: "));   //send to COM port 19200 baud
          Serial1.print(gps.location.lat(), 6); Serial1.print(F(",  ")); Serial1.print(gps.location.lng(), 6);
          Serial1.print(F(",  ")); Serial1.print(gps.altitude.feet(), 1); Serial1.println(F(" Ft."));
        }

Thanks,

Mike

[Felix]

I wasn't sure how the tinyGPS consumed data hence the little funny part
Nice that you got it working

[perky]

Just as an aside, what exactly does the

Code Select Expand

buff[i];

statement in the for loop do? Is this a C++ thing?

Mark.

[Felix]

Mark - yes, see this: https://stackoverflow.com/questions/8454228/how-can-i-get-the-nth-character-of-a-string

[perky]

Sorry, still don't get it from that post Felix. The statement seems to do nothing at all, there's no assignment or anything. Unless C++ interprets that as something special, I'm sure it would be a syntax error in C.

Mark.

[Felix]

Sorry, still don't get it from that post Felix. The statement seems to do nothing at all, there's no assignment or anything. Unless C++ interprets that as something special, I'm sure it would be a syntax error in C.

Mark.

It was actually this:

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tinyGps : eat some buff[i];

Pseudo c++ coding

[perky]

I meant the MLH's code, that has statement in there which is just

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buff[i];

in the for loop. What does it do???

Mark.

[Felix]

Oh, from his code block.
It's probably a glitch in his code.
It's actually a perfectly valid statement, does nothing though. I assume the compiler scraps it.

[MLH]

I missed that line, thanks.  Likely the result of a rogue cut and paste.  As expected, the code runs fine without it.

Mike