Variable problem

computer guy · 2008-09-04 12:53

Hi there,

I have a long with a string in it "010001".

so

[b]long[/b] output_command := "0100001"

I need to have a if statement check to see if each part of the string is a 1 or a 0.

It is a string to start with because it is read from a txt file on an sd card.
My code reads each line of the txt file and then needs to turn the command "0100001" into something useful.

How would I do this?

Thank you

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Post Edited (computer guy) : 9/4/2008 12:59:20 PM GMT

Mike Green · 2008-09-04 12:59

What you've posted is not a valid Spin statement. You can't have a long with "0100001" in it.

Have you looked at the Extended Full Duplex Serial object in the Object Exchange. This has
routines that convert input strings into numeric values. It calls Full Duplex Serial, but could
be modified to call the SD card routines instead. In any event, it will show you how to do
numeric string to number conversions. It has a decimal conversion routine, but I don't think
it has a binary number conversion routine. It's just a simple matter of changing a value of 10
to a value of 2 to handle binary numbers.

Post Edited (Mike Green) : 9/4/2008 1:07:22 PM GMT

computer guy · 2008-09-04 13:02

That was just a way of getting across what the variable is.

CON
        _clkmode        = xtal1 + pll16x
        _xinfreq        = 6_000_000

        linelen         = 256
obj
   term: "tv_text"
   sdfat: "fsrw"
   fmt: "format"
var
   byte lbuf[noparse][[/noparse]linelen]
   long line
   long output_time
   long output_command
   word k
pub go | x
   x := \start
   term.str(string("Returned from start", 13))
   term.dec(x)
   term.out(13)
pub start | r, sta, bytes, l
   term.start(24)
   term.str(string("Mounting.", 13))        
   sdfat.mount(8)
   term.str(string("Mounted.", 13))
   sdfat.opendir
   r := sdfat.popen(string("abe.txt"), "r")
   term.str(string("Opening returned "))
   term.dec(r)
   term.out(13)
   repeat
      l := readline
      if l < 0
         quit
      split(line)
      'Code to go here
pri readline | i, r
  i := 0
  repeat
      r := sdfat.pgetc
      if r == 13 or r == 10
          quit
      elseif r < 0
          return -1
      elseif i < linelen-1
          lbuf[noparse][[/noparse]i++] := r
  lbuf[i] := 0
  line := @lbuf

pri split(t) | i
  k := fmt.bscanf(t,0,string("%s R"),@output_time)
  k := fmt.bscanf(t,k,string(" %s"),@output_command)

PRI delay_ms(Duration)
  waitcnt(((clkfreq / 1_000 * Duration - 3932)) + cnt)

[/i]

That is the code I have.

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Mike Green · 2008-09-04 13:11

Look at the rxDec method in the Extended FDS object. It reads a line of text into a buffer, then validates it as a string of digits "0"-"9" with an optional leading sign "+" or "-", then converts the digit string to a number. It should be simple to change the 10s in the method to 2s, change the "9"s to "1"s, drop the sign check, and drop the initial reading of the text into the buffer since you have that already.

computer guy · 2008-09-04 13:15

Will have a look at it in the morning.

Thank you

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computer guy · 2008-09-05 06:23

Hi Mike,

Where exactly can I find the Extended FDS object? I have searched the forums, web and obex however cannot find it anywhere.

Thank you

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computer guy · 2008-09-07 03:32

Does anyone know where I can find it?

Thank you

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Oldbitcollector (Jeff) · 2008-09-07 03:37

Is this what you are looking for?

OBC

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Mike Green · 2008-09-07 03:38

It's in the Object Exchange under "Extended Full Duplex Serial".

Here's the link: obex.parallax.com/objects/31/

computer guy · 2008-09-07 03:53

Thank you. I didnt know what FDS was. I feel really dumb now.

Thank you

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computer guy · 2008-09-07 05:29

I have this code:

CON
        _clkmode        = xtal1 + pll16x
        _xinfreq        = 6_000_000

        linelen         = 256
obj
   term: "tv_text"
   sdfat: "fsrw"
   fmt: "format"
var
   byte lbuf[noparse][[/noparse]linelen]
   long line
   long output_time
   long output_command
   word k
pub go | x
   x := \start
   term.str(string("Returned from start", 13))
   term.dec(x)
   term.out(13)
pub start | r, sta, bytes, l
   term.start(24)
   term.str(string("Mounting.", 13))        
   sdfat.mount(8)
   term.str(string("Mounted.", 13))
   sdfat.opendir
   r := sdfat.popen(string("abe.txt"), "r")
   term.str(string("Opening returned "))
   term.dec(r)
   term.out(13)
   repeat
      l := readline
      if l < 0
         quit
      split(line)
      output_time := toDec(@output_time)
      term.str(string("Dec: ", 13))
      term.dec(@output_time)
      term.out(13)
      'Code to go here
pri readline | i, r
  i := 0
  repeat
      r := sdfat.pgetc
      if r == 13 or r == 10
          quit
      elseif r < 0
          return -1
      elseif i < linelen-1
          lbuf[noparse][[/noparse]i++] := r
  lbuf[i] := 0
  line := @lbuf

pri split(t) | i
  k := fmt.bscanf(t,0,string("%s R"),@output_time)
  k := fmt.bscanf(t,k,string(" %s"),@output_command)

PRI delay_ms(Duration)
  waitcnt(((clkfreq / 1_000 * Duration - 3932)) + cnt)

pri toDec(data) : Value | place, ptr, x
{{
   Accepts and returns serial decimal values, such as "1234" as a number.
   String must end in a carriage return (ASCII 13)
   x:= Serial.rxDec     ' accept string of digits for value
}}   
    place := 1
    value := 0                               
    if (data[noparse][[/noparse]0] => ("0")) and (data[noparse][[/noparse]0] =< ("9")) 
      value := value + (data[noparse][[/noparse]0]-48) * place
    elseif data[noparse][[/noparse]0] == "-"                                  
         value := value * -1
    elseif data[noparse][[/noparse]0] == "+"                               
         value := value
[/i]

This input:

32736327 R 100001
36828367 R 100001
38874388 R 100001
45012449 R 100001
49104490 R 010001

But have this output:

Dec:
6272
Dec:
6272
Dec:
6272
Dec:
6272
Dec:
6272
Dec:
6272

Can someone please take a quick look at my code and see what needs to be done to get this to work.
I need both output_time and output_command as a number but am just trying to get output_time to work at the moment.
The other should be easy.

Thank you

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StefanL38 · 2008-09-07 11:07

Hello computerguy,

if i take a QUICK look at your code i can't find the place where the conversion is done

taking a middlelong look at it i see that the method todec still looks for DECIMAL values instead for BINARY values

could you please comment almost each line what you INTEND to do

to me it seems like you have still lack of understanding what longs and pointers to strings are and how to use pointers and strings

f.e. the variable output_time is defined as a long
this means it can contain FOUR bytes (=32bits)

I don't know the fomat functions in detail but one thing is for sure:
there has to place reserved in memory to store the strings in it

if the command fmt.bscanf(t,0,string("%s R"),@output_time)
should store the string at adress of output_time and the string is longer than 4 bytes
it will override the content of the following long output_command !!

inside a string every character needs a byte=8bits. A string of 10 characters needs 10 bytes of memory and you have to reserve it

so i guess one thing to is to define bytearrays where the characters of the strings find place to be stored

the other thing is to change the method ToDec to a NEW method ToBinary
take a look at wikipedia how binary numbers work and then you can program the method yourself

best regards

Stefan

computer guy · 2008-09-07 11:36

fmt.bscanf(t,0,string("%s R"),@output_time) only accepts a long as the output.

Changing

   long output_time
   long output_command

TO

   long output_time[noparse][[/noparse]linelen]
   long output_command[noparse][[/noparse]linelen]

Has solved the problem of the time and command becoming over written.
However I am sure this uses up excess memory.

This is the function.

PUB bscanf(str,si,fmt,arg): index | width,bi,sign,p,skip,sorg
  '/**
  ' * Scan formatted string into variable, maintaining formatted string index
  ' * (special version of sscanf, to ease porting scanf and sscanf with multiple arguments)
  ' * format specifiers for byte, word, long: %c,%d,%i,%b,%o,%u,%x
  ' * format specifier for string: %s
  ' * field specification (example)
  ' *   %*4d where * specifies to scan but not assign scanned value
  ' *              4 (maximum) field width to scan
  ' *
  ' * Example:
  ' * An original C sscanf statement like
  ' * sscanf(buffer,"outside temperature %d %s inside temperature %d %s",&outtemp,outunit,&intemp,inunit);
  ' * would be written as:
  ' * OBJ
  ' *   fmt: "Format"
  ' * VAR
  ' *   byte buffer[noparse][[/noparse]128] 'holds string to scan
  ' *   byte outunit[noparse][[/noparse]16] 'to hold celsius/fahrenheit
  ' *   byte inunit[noparse][[/noparse]16]  'to hold celsius/fahrenheit
  ' *   long outtemp
  ' *   long intemp
  ' *   word k
  ' * PUB
  ' *   k := fmt.bscanf(@buffer,0,string("outside temperature %d "),@outtemp)
  ' *   k := fmt.bscanf(@buffer,k,string("%s "),@outunit)
  ' *   k := fmt.bscanf(@buffer,k,string("inside temperature %d "),@intemp)
  ' *   k := fmt.bscanf(@buffer,k,string("%s"),@inunit)
  ' *
  ' * The original sscanf is simply split up in smaller bscanf statements that take only 1 argument.
  ' * The variable k keeps track of the parsing position.
  ' *
  ' * @param str Character array holding formatted string to be scanned
  ' * @param si Start index in str to read from
  ' * @param fmt String defining format
  ' * @param arg address of variable to hold scanned value
  ' * @return Index in str pointing at next position to read
  ' */
  sorg := str
  str += si
  repeat while byte[noparse][[/noparse]fmt] <> 0
    if isspace(byte[noparse][[/noparse]fmt])                    '// white space in format
      repeat while isspace(byte[noparse][[/noparse]str])
        ++str           '// skip white space in str
      if byte[noparse][[/noparse]str] == 0
        return 0
      ++fmt
      next
    if byte[noparse][[/noparse]fmt] <> "%"            '// non-white space in format but no %
      repeat while isspace(byte[noparse][[/noparse]str])
        ++str           '// skip white space in str
      if byte[noparse][[/noparse]str] == 0
        return 0
      if byte[noparse][[/noparse]str] <> byte[noparse][[/noparse]fmt]
        return str-sorg      '// no match in str
      ++str
      ++fmt
      next
    ++fmt                                      '// skip over %
    if byte[noparse][[/noparse]fmt] == "*"
      skip := true
      ++fmt
    else
      skip := false
    if isdigit(byte[noparse][[/noparse]fmt])                     '// field width
      bi := 0
      repeat while isdigit(byte[noparse][[/noparse]fmt])
        buf[noparse][[/noparse]bi++] := byte[noparse][[/noparse]fmt++]
      buf[noparse][[/noparse]bi] := 0
      width := atoi(@buf)
    else
      width := 32767
    repeat while isspace(byte[noparse][[/noparse]str])
      ++str
    if byte[noparse][[/noparse]str] == 0
      return 0
    case byte[noparse][[/noparse]fmt]
      "c": if !skip
             byte[noparse][[/noparse]arg] := byte[noparse][[/noparse]str]
           ++str
      "s": bi := 0
           repeat while (width > 0) AND !isspace(byte[noparse][[/noparse]str])
             width--
             if !skip
               byte[noparse][[/noparse]arg++] := byte[noparse][[/noparse]str]
             ++str
           if !skip
             byte[noparse][[/noparse]arg] := 0            '// closing 0
           if byte[noparse][[/noparse]str] == 0
             return 0
      other: if byte[noparse][[/noparse]str] == "-"
               sign := -1
               ++str
             else
               if byte[noparse][[/noparse]str] == "+"
                 sign := 1
                 ++str
               else
                 sign := 1
             if isxdigit(byte[noparse][[/noparse]str])              '// integer value
               bi := 0
               repeat while (width > 0) AND isxdigit(byte[noparse][[/noparse]str])
                 width--
                 buf[noparse][[/noparse]bi++] := byte[noparse][[/noparse]str++]
               buf[noparse][[/noparse]bi] := 0
               case byte[noparse][[/noparse]fmt]
                 "d","i": p := sign * atoi(@buf)
                 "b": p := atoib(@buf, 2)
                 "o": p := atoib(@buf, 8)
                 "u": p := atoib(@buf, 10)
                 "x": p := atoib(@buf, 16)
                 "f": 'not supported yet        '//32bit floating point
                      skip := true
                      p := 0
                 other: skip := true
                        p := 0
               if !skip
                 LONG[noparse][[/noparse]arg] := p
    ++fmt
  return str-sorg

I have no idea how todec works as its not my code and not commented at all.

Thank you

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computer guy · 2008-09-07 13:12

All I need to do now is convert "32736327" (as a long array) to 32736327.

Any ideas?

Thank you

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Mike Green · 2008-09-07 15:04

Call this routine with the address of "32736327" as the parameter
and it will return the value 32736327. The string has to be terminated
with some non-digit byte (like the normal zero byte that ends a string).
If the string starts with a non-digit byte, the value zero will be returned.

PRI convertToDec(stringAddress) | temp
  temp := byte[noparse][[/noparse]stringAddress]
  repeat while temp => "0" and temp =< "9"
    result := result * 10 + (temp - "0")
    temp := byte[noparse][[/noparse]++stringAddress]

computer guy · 2008-09-07 22:07

Thanks Mike.

It still only returns a weird number like 6284.
I will upload my code (commented) when I get home this afternoon.

Thank you

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Mike Green · 2008-09-07 22:41

I just noticed you had "term.dec(@output_time)" for some reason in your program.
This will display the address of output_time, not the value of it. You want:
"term.dec(output_time)"

computer guy · 2008-09-08 05:49

Thank you Mike.

Now I just need to work out how to analyse each individual value of the number.

I am still learning about bytes, arrays and such.

I would have thought that output_command[noparse][[/noparse] 0] would have given me the first number in output_command and output_command[noparse][[/noparse] 1] would have given me the second.
But it still gives me the entire number.

Also how do I stop the decimal conversion code from truncating the 0's at the start of output_command.

Basically

means that buttons 1 and 6 are pressed.
But the conversion code gets

and returns

Thank you

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computer guy · 2008-09-09 07:00

Anyone have any thoughts?

Thank you

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StefanL38 · 2008-09-09 15:11

hello computerguy,

oh i have a lot thoughts

first is "the members of the forum are willing to help. But there has to come something more from you."

second is "i would like to aks you if you had understand the following line of code"

[noparse][[/noparse]code]

result := result * 10 + (temp - "0")

[noparse][[/noparse]\code]

do you UNDERSTAND what happens here ?

simple answer "yes" or "no"

complete answer: description in your own words what it does

another problem I have:

it is very hard to imagine what you have CODED without seeing your code

nothing is clear

did you use the method that Mike posted above ?

did you use the "old" ToDec-method from your program more above?

everything gets clear if you add comments to your code in that lines where you think the problem isl
an then
please, please, please, please post your COMPLETE code as an attachment
another way could be a test-program just containing the interesting part but still as a COMPLETE program
NO CODE-SNIPPETS !

and if you add an example of what you "put in" and what "comes out" it will become much easier to analyse the whole thing

did you try to debug your code by sending the values of every variable engaged in the conversion to a terminalsoftware like PST.EXE ?

another thing ASCII-code characters have values between 0 and 255 these values fit in one BYTE
define output_time output_comman

as BYTE-arrays NOT as LONG-arrays

best regards

Stefan

computer guy · 2008-09-10 06:49

Hi Stefan,

No I dont understand the line

result := result * 10 + (temp - "0")

I used the code that Mike posted above.

I will finish commenting my code and upload it.

The values are read from an SD card. The output is displayed using the TV text driver.

output_time and output_command have to be a long array as the code that splits the string will only accept a long array.

Thank you for your help.

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StefanL38 · 2008-09-10 19:37

Hello Computerguy,

this line above is from the code that mike posted and that you are using.

i think the array should be a byte-array because
the PUB bscanf(str,si,fmt,arg): index | width,bi,sign,p,skip,sorg

uses commands "byte[noparse][[/noparse]str]" all the time

parameters have to be longs and the parameter "str" of PUB bscanf has to be a long too
But parameter "str" is the POINTER to the BYTE-Array containing the string and NOT the array itself

if the string is "ABC" which is in ASCII-code A=65, B=66, C=67
the byte-array contains

first byte 65
second byte 66
third byte 67

the POINTER contains the ADRESS WHERE the values 65 66 67 are stored

Let's say the base-adress of the string-pointer str is 1000

if you increment the value of str by one and use it with byte[noparse][[/noparse]str] you are accessing
RAM-Byte 1001

if you use it with long[noparse][[/noparse]str] you access RAM-Byte 1005

or other way round if you have stored the characters of your string in a LONG-array

Let's say the string is "ABC" which is in ASCII-code A=65, B=66, C=67
the RAM-bytes contain the following
byte 1000: 65
byte 1001: 0
byte 1002: 0
byte 1003: 0
byte 1004: 66
byte 1005: 0
byte 1006: 0
byte 1007: 0
byte 1008: 67
byte 1009: 0
byte 1010: 0
byte 1011: 0

now the PUB bscanf(str,si,fmt,arg): index | width,bi,sign,p,skip,sorg
accesses the string by byte[noparse][[/noparse]str]
with the first character this is working

then str which contains value 1000 is incremented by one
new value 1001
byte[noparse][[/noparse]str]=byte[noparse][[/noparse]1001] gets back value 0 INSTEAD of 66 wich ist stored in byte 1004

I hope you can see that you have to take care of the variabletypes very much if your code uses POINTERS.

And this is a very good example why it makes sense to understand the code in medium detail-deph

Using code with NO understanding at all leaves you in the position of COMPLETE dependence of others
As soon as a strange problem occurs you have to ask an expert about this.

Again my question: do you know how to use FullDuplexSerial to send debug-information to the PC ?
yes or no

best regards

Stefan

computer guy · 2008-09-11 06:09

Thank you Stefan.

Yes I do know how to use FullDuplexSerial to send information to a PC terminal.
I have a tv connected and would prefer to use that for debug.

Thank you

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computer guy · 2008-09-11 10:12

Here is my code. I have commented it as much as possible.

Thank you

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computer guy · 2008-09-14 05:19

I don't mean to rush anyone but could someone please take a look at the few things I need help with please.

1. Getting output_time and output_command to be byte arrays.
2. Getting output_command to have prefixed 0's.
3. An if statement to check if each numeral in output_command is a 1 or a 0.

Thank you

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computer guy · 2008-09-14 22:25

Here is the latest code.

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computer guy · 2008-09-15 10:03

Updated code.

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Variable problem

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