One of those 'passing strings' questions...

Hugh

Sorry, another silly question...

I am trying to select a number of characters from a string (to be sent via simple_debug). The code is below but instead of extracting ten characters as intended I only receive four - do commas have an impact on the way strings are handled?

PUB BTSendGPSorFF (a, b, c, prefix) | indexC , scratch

' ~Scratchpad2~ is a global long, size "[50]"
bytemove(@scratchpad2, string("$GPRMC,123519,A,4807.038,N,01131.000,E,022.4,084.4,230313,003.1,W*6A"), 50)


' Fill ~scratch~ with zeroes - anything we move to it subsequently will be zero-terminated, allowing us to treat it as a string    
bytefill(@scratch, 0, 50)                                                                              


'Move ten bytes of ~scratchpad2~ into ~scratch~
bytemove(@scratch, @scratchpad2 + 20, 10)


' Send the prefix (string) passed in the call to this PUB.
      debug.str(prefix)


' Send ~scratch~ as a string. Because we filled ~scratch~ with zeroes it will be zero-terminated                                                                                 '
      debug.str(@scratch)


' Send a CR      
      debug.tx(13)

I thought I'd finally got my head around strings and things but apparently not.

Any help would be really appreciated.

Thanks
Hugh

T Chap

Sorry I misread and removed my reply. Not enough info to help.

Mike G

The local pointer variable, scratch, is not initialized,

There's not enough code posted to determine what "prefix" is doing or pointing to. Please post all your code!

JonnyMac

Your local variable, scratch, is a long (4 bytes) and you start by attempting to fill it with 50 zeroes -- this is overwriting your the first part code (remember, everything runs from RAM).

You need a second byte array in the global space.

Hugh

JonnyMac wrote: »

Your local variable, scratch, is a long (4 bytes) and you start by attempting to fill it with 50 zeroes -- this is overwriting your the first part code (remember, everything runs from RAM).

You need a second byte array in the global space.

Thank you Jonny - that fixed it. :thumb:

Hugh

Mike G wrote: »

Please post all your code!

With comments the top files is currently 1,356 lines so I thought better of posting all of it.

JonnyMac

You can always archive and post as an attachment when having others see your full source is useful.

My name is Jon.

Hugh

JonnyMac wrote: »

My name is Jon.

Sorry. I went by your user name rather than that in your sig.

Mike G

Hugh wrote: »

With comments the top files is currently 1,356 lines so I thought better of posting all of it.

It's practically impossible to provide a solution without all the source code. Often the problem lies elsewhere in the code base which is the situation here. My response assumed the code base contained a global buffer but the local pointer "scratch" was not initialized to the buffer address. I was wrong...a global buffer did not exist at all.

I've been trying very hard to provide more gentle responses to posts. When requesting "All the code" and receiving a response of "It's too big" is actually insulting and shows a disregard for the folks trying to help.

Please realize, I had to fill in the logic gaps by make assumptions about the code base and your programming ability which I know nothing about. Given an incomplete view of the logic I had to come up with a guess and a thoughtful response. Please keep this in mind for future posts.

Hugh

Crikey, that's two people I've annoyed in one thread - apologies all. Can we start again?!

I thought that the comments in the code would be sufficient but my over-familiarity with the code meant that in trying to include only that immediately relevant I omitted some information with which anyone coming to it cold would not be familiar. Sorry

As will be apparent from the attached code, my 'programming ability' is 'not a lot'; I am possibly being over-ambitious with what is the third generation of the same idea.

Hugh

FFGPS202 - New board, tacho - Archive [Date 2014.05.26 Time 18.58].zip