problems sending big numbers via RS232

nomad · 2009-04-21 12:17

Ref: problems send big numbers via RS232

hallo,
i have a Propeller Professional Development Board aka PPDB
with a RS232-Port.
the communications from a LinuxSystem via RS232 to the board and back is OK.

in the moment i can only send smallNumbers aka <1>
to the board with:
linux send <1>
board receive <49> as ascii (1)
board if input == 49 then make LED ON
board send "5" back to linux
this is ok

The Problem:
i will send a big decimal-Numbers to the Board
bigNumber <12345>

my first idea, is
on the linux system i cut the bigNumber into single bytes aka 12345 = <1><2><3><4><5>
and send this 5 times to the board
the board receive 5 x the single numbers

the code:

Con
  _clkmode = xtal1 + pll16x
  _xinfreq = 5_000_000
   
  Rx   = 31                            
  Tx   = 30                                 
  baud = 9600  
 
OBJ                                              
   ' Ser : "FullDuplexSerial"
   Ser : "Extended_FDSerial"

Var
  byte input0, input1,input2, input3, input4
  byte output
  long inputInt0, inputInt1, inputInt2, inputInt3, inputInt4
  long inputsInt
  byte asciiBase 
     
Pub Main

  dira[noparse][[/noparse]0]~~   ' Pin05 set output leds  
  outa[noparse][[/noparse]0]~    ' Pin05 set low

  asciiBase := 48

  Ser.Start(Rx,Tx,0,baud)  
       
  repeat 
     input0 := Ser.RxTime(100)  ' byte as ascii
     input1 := Ser.RxTime(100)  ' byte as ascii
     input2 := Ser.RxTime(100)  ' byte as ascii
     input3 := Ser.RxTime(100)  ' byte as ascii
     input4 := Ser.RxTime(100)  ' byte as ascii
                  
     waitcnt(clkfreq / 10 + cnt)

     convertToInt
     
     if inputsInt == 12345
        !outa[noparse][[/noparse]0]
        Ser.str(string("5"))
            
     waitcnt(clkfreq / 10 + cnt)

PUB convertToInt
   inputInt0 := (input0 - asciiBase) * 100000
   inputInt1 := (input1 - asciiBase) * 1000
   inputInt2 := (input2 - asciiBase) * 100
   inputInt3 := (input3 - asciiBase) * 10
   inputInt4 := input4 - asciiBase

   inputsInt := inputInt0 + inputInt1 + inputInt2 + inputInt3 + inputInt4

is this a correct code?
is this possible?
when i running the whole stuff
- connections ok
- but no led-blinking ???
- and when i send the output aka inputsInt to the linuxSystem
with Serial.dec(inputsInt)
- the linuxSystem receive grumble stuff not <12345>

the second idea is:

on the Extended_FDSerial object gives a functions

x := Serial.rxDec

this functions should be ok, for receive bigNumbers
but, as per the doku " String must end in a carriage return (ASCII 13) <CR>
under linux i can send : "12345\r"
"\r" is the CR
but when experiment with this stuff, nothing is ok

Thanks for help, trick, tipps and hints

regards
nomad

StefanL38 · 2009-04-21 13:08

Hello Nomad,

for debugging this

first step: write a small testprogramm than can send a byte as a hexadecimal value
that the PC receives short strings like "$FF", "$0D", "$30" etc.
This means send a "$" and then use the .Hex.-method from ExFDS (Extended_FDSerial)

I HIGHLY recommend testing this FIRST step until it works 101% properly !

second step: then send your big number from the PC to the propeller
send BACK - ALL the received bytes as hexadecimal strings "$30" etc.
to see what you really receive

If you need more support on this post CONCRETE questions

best regards

Stefan

nomad · 2009-04-21 15:12

hi stefan
excuse me:
with this spin-programm all stuff running:

1) linux send a string as "12345\r" // \r is CR
2) board receive the BigNumber with: inputInt := Ser.rxDec
3) if inputInt == 12345
then blueLed ON
4) send back a) <5> for it's ok
or
send back b) Ser.dec(inputInt) // for debuging

Thanks for your verry good help.
Regards
nomad

the running code:

{

   serialPropDevBoard11.spin

   dd. 21.04.2009



   input from linux as string == "12345\r"                         

******************************************************************************************

}



Con

  _clkmode = xtal1 + pll16x

  _xinfreq = 5_000_000

   



  Rx   = 31                            

  Tx   = 30                                 

  baud   = 9600  



OBJ                                              

   ' Ser : "FullDuplexSerial"

   Ser : "Extended_FDSerial"



Var

  byte input

  byte output

  long inputInt

     

   

Pub Start



  dira[noparse][[/noparse]0]~~   ' Pin05 set output leds  

  outa[noparse][[/noparse]0]~    ' Pin05 set low



  Ser.Start(Rx,Tx,0,baud)  

       

  repeat 



     inputInt := Ser.rxDec  ' long bigNumbers

     waitcnt(clkfreq / 10 + cnt)



     if input == 12345

        !outa[noparse][[/noparse]0]

        Ser.str(string("5"))

        ' or
        Ser.dec(inputInt)
         

     waitcnt(clkfreq / 10 + cnt)

           

    

{*************************************************}

simonl · 2009-04-21 20:46

@nomad:

What your Prop' is receiving is the ASCII character (byte) representation of the string 12345. I see (from your original post) that you've tried to convert this to an integer, but I can't immediately see why your conversion's not working. However, I'm in the process of writing a "Guide to Propeller Communications", so I've attached a modified version of one of my tutorial app's that will do what you're after - I hope it helps (and thank you for giving me the opportunity to give something back to this forum!).

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Cheers,
Simon

www.norfolkhelicopterclub.com

You'll always have as many take-offs as landings, the trick is to be sure you can take-off again

BTW: I type as I'm thinking, so please don't take any offence at my writing style

simonl · 2009-04-21 21:14

Of course, what I've done is show you how to compare the input against a string, which I think achieves what you're wanting. However; if you're really wanting to convert the input into a numeric value, I'd suggest you look at the "numbers" object.

To convert the input string (e.g. inputStr) to a numeric value (e.g. inputVal), you would call the "FromStr" method:

inputVal := Num.FromStr( inputStr, Num#DEC )

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Cheers,
Simon

www.norfolkhelicopterclub.com

You'll always have as many take-offs as landings, the trick is to be sure you can take-off again

BTW: I type as I'm thinking, so please don't take any offence at my writing style

nomad · 2009-04-22 10:19

hi Simon,
Thanks for your Help.
i am happy that the stuff running...
cheers
nomad

problems sending big numbers via RS232

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