Thanks for your help so far Tsvetan!

I still need help with this chip...

The following is the code that I use to echo a caracter back to the
master...

Main1
     Call         GetTDAData             ;Wait for any reception of data
from master unit!!!
     movfw     TDARxReg
     Movwf     TDATxReg
     Call         SendTDAData          ;sent same data back to master
unit!!!

     movlw       B'01000'                   ;Toggle PCB led
     xorwf         PortA,f

goto           Main1

;************************ END OF MAIN PROGRAM
*******************************

SendTDAData
     bsf             TDATxData
     nop
     bcf             TDAPD                  ;wake chip from power down mode

     #movlf       .8, CountReg
     bcf             TDATxData
     call            BitTime_600

NextTDATxBit
     bcf             CarryBit
     rrf              TDATxReg,F
     btfsc          CarryBit
     bcf             TDATxData

     btfss          CarryBit
     bsf             TDATxData
     call             BitTime_600
     decfsz       CountReg,F
     goto           NextTDATxBit

     bsf             TDATxData
     call             BitTime_600
     bsf             TDAPD                  ;put chip back in power down
mode
     return

GetTDAData
     bcf             TDAPD                 ;wake chip from Power down mode
     nop

GetTDADataLoop
    btfsc           TDARxData
;?????????????????????????????????????????
    goto            GetTDADataLoop            ;?Must I put code here to test
for interference or signal?

;?????????????????????????????????????????
    clrf                TDARxReg
    call               StartBit_600

     #movlf         .8, CountReg

TDARxBit
     bcf              CarryBit
     btfsc           TDARxData
     bsf              CarryBit
     rrf                TDARxReg,F
     call              BitTime_600
     decfsz         CountReg,F
     goto           TDARxBit
     bsf              TDAPD                  ;put TDA chip back in power
down mode
     return

;****************** 600 BPS BIT DELAY PROCEDURE
*****************************
StartBit_600
         #movlf     .50, StartBitReg

StartBitLoop_600
        decfsz      StartBitReg,F
        goto          StartBitLoop_600
        movlw       StartDelay_600
        goto          StartUp_600

BitTime_600
        movlw       K
StartUp_600
        movwf       MultiplyReg

FineTune_600
 #movlf  Baud_600, DelayCountReg
BitLoop_600
        decfsz          DelayCountReg,F
        goto               BitLoop_600
        Decfsz          MultiplyReg,F
        goto               FineTune_600
        return
;***************** END OF 600 BPS BIT DELAY PROCEDURE
***********************

It seems like there is a lot of interference on the current line because the
led is blinking the whole time even if no data is send to the slave
unit!!!!!!!!

I am using the scematic that is in the TDA5051 datasheet with line isolation
and improved sensitivity....

Must I rather use the one without the improved sensitivity??

Regards

Francois


----- Original Message -----
From: Tsvetan Usunov <usunov@OLIMEX.COM>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Thursday, December 28, 2000 9:42 AM
Subject: Re: [PIC]: TDA5051


> > Is it possible to send sync data as well?
> >
> > I have one master and many slaves - thas I have to send a packet of data
> > with the ID of the slave that must react on a intuction...
> >
> > Regards
> >
> > Francois
>
> when you drive your master unit Tx up and down, the slave units Rx ports
> will go up and down
> if the communication will be the sync or async depend only of your
software
> implementation
>
> Regards
> Tsvetan
> -----
> PCB prototypes for $26, http://www.olimex.com
>
> --
> http://www.piclist.com hint: PICList Posts must start with ONE topic:
> [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads
>
>

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics