xon/xoff are characters send. With USB this is does not work better than CR or any other character. Target and PC do not communicate character by character any more. Terminal emulaters do not stop in time, there are buffers inbetween, overrunning oldfashion xon/off protokolls.
Michael Am 02.08.2014 um 15:07 schrieb Erich Waelde: > Hi Paolo, > > Thank you for your response. > > On 08/02/2014 01:39 PM, Paolo Garro wrote: >> Hi Erich >> There is nothing wrong. >> Me too I'm reading the echo char while transmitting. >> The timeout problem is while receiving form the mcu. >> After transmitting a line you stay earing for a response. >> How can I know when the response is complete? > When you received the prompt "\n> ". >> Wait a lot of seconds is not so logic. >> How can I know if the mcu is ready to receive another line? > When you received the "\n> " prompt, too, I think. > >> An XON ending char would be fine... > > I have the timeout question in my stuff as well, but it is > not easy. There are several (more than 1) controllers on > the same rs485 bus. I do not want them to just send anything > unless I asked them. So I removed any output from startup > including the prompt. When I address one controller I send > its address (with the highest bit set) and it shall "wake up" > and present it's prompt. I also added the controller address > to the prompt itself, a station with address $4f will answer > as > "\n~4F> " > and the programm controlling everything needs to wait for this > string to be received. This particular setup cannot work with > xon/xoff. The bus has only one pair of cables. Therefore I want > to see each and every character echoed, so I know the remote > station is still avalailable (connected and alive). But that > is just my setup and I'm not saying, you are wrong. I just > doubt that it will help you as much as you think. > > > So lets assume for the moment, you want XOFF/XON hw flow control. > Fine. So you select two output pins of the controller to drive > the signals. Still fine. Next question: where in amForth do you > assert the xon and xoff signals? I might be wrong, but the > prompt function looks like the correct place to me to assert XON. > You are at the same place, where the prompt is sent. So does > XON help you? > > Again, I might be wrong alltogether. And if you really want xon/xoff, > it can definitely be added to your system. And if it works, great! > > You can add > .set WANT_XON_XOFF = 1 > in your "template.asm" or equivalent file and use it in any other > assembly file like so > > .if WANT_XON_XOFF == 1 > .set XON_XOFF_PORT = PORTD ; io location, not mem mapped > .set XON_XOFF_PIN = 7 > .endif > > or similar. If you want to have a FORTH constant at the same time > to know for example the pin number, then you create the equivalent > asm code in a file (words/xon_xoff.asm for example): > > ; asm(XON_XOFF_PIN) constant xon_xoff_pin > VE_XON_XOFF_PIN: > .dw $FF0C > .db "xon_xoff_pin" > .dw VE_HEAD > .set VE_HEAD = VE_XON_XOFF_PIN > XT_XON_XOFF_PIN: > .dw PFA_DOVARIABLE > PFA_XON_XOFF_PIN: > .dw XON_XOFF_PIN > > this creates the "xon_xoff_pin" as a forth constant. Please note > that this code is adapted from my experiments with amForth-4.6, so > it might need to change for a current version. The file needs to > be included into your build via dict_appl.inc > > .if WANT_XON_XOFF == 1 > .include "words/xon_xoff.asm" > .endif > > Rebuild amForth, test, repeat. Look into core/words/ for inspiration. > > Hope this helps and good luck! > > Cheers, > Erich > > > ---------------------------------------------------------------------- > -------- > Want fast and easy access to all the code in your enterprise? Index > and > search up to 200,000 lines of code with a free copy of Black Duck > Code Sight - the same software that powers the world's largest code > search on Ohloh, the Black Duck Open Hub! Try it now. > http://p.sf.net/sfu/bds > _______________________________________________ > Amforth-devel mailing list for http://amforth.sf.net/ > Amforth-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/amforth-devel ------------------------------------------------------------------------------ Want fast and easy access to all the code in your enterprise? Index and search up to 200,000 lines of code with a free copy of Black Duck Code Sight - the same software that powers the world's largest code search on Ohloh, the Black Duck Open Hub! Try it now. http://p.sf.net/sfu/bds _______________________________________________ Amforth-devel mailing list for http://amforth.sf.net/ Amforth-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/amforth-devel
