Here are some more info regarding this matter: 1) I checked the version of serial manager of my Sony Clie, and it was 3, PalmOS has version 4 now, I wonder if they have a fix in this version.
2) If I stop the data stream from my serial communication device right before mid-night, and resume it right after it, it works fine. From this, it seems to me the problem is in software end, or to say the serial manager didn't set the RS232 controler into a weired state at mid-night. Here is my assumption: the problem comes from the handling of data overflow at the RS232 controller when ISR is suspended at mid-night (Palm may need to do some major house-keeping jobs at time). Once overflow, the serial manager requires SrmClearErr to fix the problem and this SrmClearErr will go out and reset the hardware, causing even longer delay in the serial communication. At this point, I believe it is a real design flaw in PalmOS. > > Hi, all > > I am writing a program utilizing the serial port on palm to receive > data from a serial communication source. Everything works fine until > the very moment of mid-night --- one may preset the clock to > 11:59pm so that he doesn't have to wait for a whole day to see the > result. At exactly 12:00AM, the serial port will stop receiving > data, to make it worse, instead of losing a few bytes, the only way > to resume the receiving is to call SrmClearErr(gPortID), hinting a > serious prolbem in either the serial manager or even the serial > manager. > > Any one has suggestion regarding this? > > Thanks, > > XC > > ps. Test condition: > > 1) Tried three different baud rate: 115200 baud, 57600 baud and 19200 > baud > 2) Tried both default serial buffer size, and user-allocated 16384 > bytes buffer. > 3) Data rate: 245 bytes per second, regardless the baud rate > 4) Tested on Palm m105 and Sony Clie: Repeatable same finding > I've just tested it, here are my results: - Palm III (Palm OS 3.0) (serial cradle): Communication freeze and my app fail to complet its communication - Palm m505 (Palm OS 4.0) (USB cradle): Communication freeze for about 1 sec. than it comme back. My app is able to complet its communication (after a few retry a guess) - Will try with a m515 and a serial cradle and comme back to you. -- ---------------------------------------- Regis St-Gelais ing. Ingénieur de projets / Project engineer Développement informatique / Software development Le Groupe ISAC Inc. -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/
