Transmission speeds over 9600 require some type of flow control.  115Kbaud
requires hardware flow control enabled.  Without it, communications will be
unreliable and you may loose some bits.


----- Original Message ----- 
From: "Riccardo Cohen" <[EMAIL PROTECTED]>
To: "Palm Developer Forum" <[EMAIL PROTECTED]>
Sent: Monday, November 10, 2003 7:22 PM
Subject: speedy serial


> Hi,
> I would like to speed up my serial communication. For the moment, it
works, but it takes 20 seconds
> to transfert 100 strings from PC to Palm Tungsten (through cradle on
serial)
>
> To open the port, I do an ExtOpen, change the params, and set receive
buffer :
> ===================================================
> config.baud=115200;
> config.function=serFncUndefined;
> config.drvrDataP=NULL;
> config.drvrDataSize=0;
> config.sysReserved1=0;
> config.sysReserved2=0;
> SrmExtOpen(
>        serPortCradlePort,
>        &config,
>        sizeof(config),
>        &port);
>
> Int32 sett=
>        srmSettingsFlagStopBits1 |
>        srmSettingsFlagBitsPerChar8;
> UInt16 size=sizeof(Int32);
> SrmControl(port,srmCtlSetFlags,&sett,&size);
>
> UInt8 *sync_buf=(UInt8 *)MemPtrNew(4096);
> SrmSetReceiveBuffer(port,sync_buf,4096);
> ===================================================
>
> Of course I set the same params on the PC : same speed, 1 bit stop, 8 bit
data, and no parity, no
> control.
>
>
> To exchange data, I simply receive bytes with SrmReceiveWait/SrmReceive,
then send an aknowledge
> single byte = 1 with SrmSend
>
> It appears that if I set the timeout to 20 ticks, communication will stop
before end (no data
> received within the timeout). If the timeout is 40 ticks, the
communication goes until the end, but
> it is so slow !
>
> I'm not an expert in serial comm, thanks for any information about speed.
>
> PS: I do send acknowledge byte to be able to work with slow devices like
previous palms. A non
> acknowledged data sent did not work on palm515 while it worked on palm
tungsten.
>
>
> -- 
> Riccardo Cohen
>
> Articque
> Les Roches
> 37230 Fondettes
> France
> web = http://www.articque.com
> tel: +33 02 47 49 90 49
> fax: +33 02 47 49 91 49
>
>
> -- 
> For information on using the Palm Developer Forums, or to unsubscribe,
please see http://www.palmos.com/dev/support/forums/
>


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