integer to ASCII object?

Jonathan · 2015-01-15 10:37

Hi All,

I googled and searched the obex but didn't find an integer to ascii converter. I did see reference to there being something of the sort in PASM in fullduplexserial and similar, but not being a ASM guy I couldn't figure it out.

Before I start trying to write one, does anyone have one handy?

Thanks!

Jonathan

Duane Degn · 2015-01-15 10:43

There are lots of objects floating around to do this. The "Dec" method in most serial drivers give an example of converting numbers to ASCII characters.

The "Numbers" object in the Propeller Library has methods to format numbers as characters in a string.

I like to use the object "StrFmt.spin" when converting variable to characters. There's a copy of the object in my GitHub "EddieFirmware" repository.

Dave Hein · 2015-01-15 10:49

Here's the routine I use in the CLIB object.

PRI itoa10(number, str) | str0, divisor, temp
{{
  This private routine is used to convert a signed integer contained in
  "number" to a decimal character string.
}}
  str0 := str
  if (number < 0)
    byte[str++] := "-"
    if (number == $80000000)
      byte[str++] := "2"
      number += 2_000_000_000
    number := -number
  elseif (number == 0)
    byte[str++] := "0"
    byte[str] := 0
    return 1
  divisor := 1_000_000_000
  repeat while (divisor > number)
    divisor /= 10
  repeat while (divisor > 0)
    temp := number / divisor
    byte[str++] := temp + "0"
    number -= temp * divisor
    divisor /= 10
  byte[str++] := 0
  return str - str0 - 1

Jonathan · 2015-01-15 10:50

Thanks Duane. I'm looking at a DEC function but can't seem to make sense of what it is doing. I'll keep noodling.

Jonathan

Electrodude · 2015-01-15 11:41

The integer to ascii converter functions in FullDuplexSerial are written in Spin. Only the actualy UART driver (which doesn't care what its data is) is written in PASM.

pik33 · 2015-01-15 11:41

These are ttwo functions from my P1V retromachine vga driver. The first outputs decimal string; the second outputs hex string.

' add this in var section
byte n_string[12]  ' string buffer for inttostr and hextostr   


pub inttostr(i) |q,pos,k,j

'********************************************************************************
'
'             Convert integer to dec string
'             Return a pointer
'
'********************************************************************************

j:=i
pos:=10
k:=0

if (j==0)
  return string ("0")

if (j<0)
  j:=0-j
  k:=45

n_string[11]:=0
repeat while (pos>-1)
  q:=j//10
  q:=48+q
  n_string[pos]:=q
  j:=j/10
  pos-=1
repeat while n_string[0]==48
  bytemove(@n_string,@n_string+1,12)

if k==45
   bytemove(@n_string+1,@n_string,12)
   n_string[0]:=k

result:=@n_string


pub hextostr(i) |q,pos,k,j


'********************************************************************************
'
'             Convert integer to hex string
'             Return a pointer
'
'********************************************************************************

j:=i
pos:=10
k:=0

if (j==0)
  return string ("0")

if (j<0)
  j:=0-j
  k:=45

n_string[11]:=0
repeat while (pos>-1)
  q:=j//16
  if (q>9)
    q:=q+7
  q:=48+q
  n_string[pos]:=q
  j:=j/16
  pos-=1
repeat while n_string[0]==48
  bytemove(@n_string,@n_string+1,12)

if k==45
   bytemove(@n_string+1,@n_string,12)
   n_string[0]:=k
result:=@n_string

Duane Degn · 2015-01-15 11:51

Not that's likely to be an issue very often but I think your method will incorrectly display the max negative value. If you take a look at Dave's code, you can see he has an exception for $80000000.

Also, FYI, "j"=0-j" can be written as "-j". When the variable is by itself the minus sign negates the variable's value. Dave's "number := -number" could also be reduced to "-number".

lonesock · 2015-01-15 13:39

This one is decently small Spin code:

PUB Dec( value ) | denom
{{
  * Sends a decimal number over the serial link.
  > value : the number to send.

  e.g. Dec( 10 ) ' sends "10"
}}
  ' if negative, note that
  if value < 0
    ||value
    tx( "-" )
  ' start with the largest possible power of 10 to fit in 32 signed bits
  denom := 1_000_000_000
  repeat 9
    ' I have a non-0 digit, or we already had one
    if result |= (value => denom)
      tx( value / denom + "0" )
    value //= denom
    denom /= 10
  ' always show the last character (and denom == 1)
  tx( value + "0" )

Jonathan

Jonathan · 2015-01-15 14:03

First, many thanks for the responses.

I have spent the last while reading and boy, my ignorance is amazing. For starters, I wasn't really asking the right question. I think I'll start a more appropriately titled thread.

@Jonathan - that is a useful snip. I'll need that. Thanks.

tonyp12 · 2015-01-15 14:27

Here is a PASM version I made.
It does not take in to account that Spin variables are signed and can be negative, maybe I update that.

{ Sends a 10 character DEC of a HUB Address value, at a fixed interval }

PUB start(address)
    cognew (@entry,address)

DAT           org 0
entry         mov       DIRA,_bit30
              mov       cnt,#7                  '7 cycle overhead
              add       cnt,cnt                 'add current cnt
loop1         waitcnt   cnt,#200                'wait and then add 200 for below overhead
              rdlong    temp,PAR
              movs      decimal,#table     
              mov       charcnt,#11            '10 dec chars in a long + space
loop2         mov       uartTx,#48             'start at ASCII for "0"
decimal       cmpsub    temp,0-0 wc            'try 1 Billion first
        if_c  add       uartTx,#1
        if_c  jmp       #decimal      
              cmp       charcnt,#1 wz           'last charter one?
        if_z  mov       uartTX,#32              'replace with space
              or        uartTx,#$100            'set stopbit
              shl       uartTx,#1               'merge in startbit               
              mov       bitcnt,#10              '10bit uart
loop3         waitcnt   cnt,_baud
              shr       UartTx,#1 wc
              muxc      OUTA,_bit30
              djnz      bitcnt,#loop3
              add       decimal,#1              'try 100mill next        
              djnz      charcnt,#loop2
              add       cnt,_second             'restart main loop with 1sec delay
              jmp       #loop1
              
_second long 80_000_000                         '/2 or /4 if you want shorter delay (insert -76540 if you want absolute sec-to-sec timing)
_baud   long 80_000_000/115200
_bit30  long |<30
table   long 1_000_000_000, 100_000_000, 10_000_000, 1_000_000, 100_000, 10_000, 1_000, 100, 10, 1,1 
temp    res 1
charcnt res 1
bitcnt  res 1
uartTx  res 1

Duane Degn · 2015-01-15 14:33

tonyp12 wrote: »

Here is a PASM version I made.

Very cool.

I've wondered about reading messages directly in PASM. I'm pretty sure manipulating characters in Spin is a bottleneck in many of my programs.

Thanks for posting your code Tony.

integer to ASCII object?

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