[En-Nut-Discussion] UART Ethernut3 stop receiveing bytes after a while

[Alain M.]

Hi Martin,

even being new to Nut/OS, I am in the RS232 thing for a loooong time. I 
would bet that you are having re-entry problems. Let's say that because 
of the debug option, the next char gets delayed up to a point that the 
next will renter the last one or that the sending char overrides the 
last. This could lead to one interrupt accurring while the last is 
running and if not properly coded this can cause problems.

You can try 2 things:
1) run the same test at much lower speeds so that you can discard some 
bug related to the debug part, then repeat it at very high speed with no 
debug just to see if it happens too
2) send a known sequence and test it at the receiver side, you can then 
split the problem between receiving/sending/debugging.

Alain

ml escreveu:
> Solved a bit :( 
> 
> if i build nutos without debug infos all work´s well. for now it´s a
> solution, but i wonder how this happens.
> in debugger i can see that the irq is never called again but the register´s
> are set correctly. i test with 
> the UART-loop in a thread. The main thread is still running after the
> mistake. The debugger sometimes tries to reach a breakpoint but want´s to
> examine a memory-adress far behind the physical memory - seems to be random. 
> 
> Martin
> 
> 
> 
> ml wrote:
>> Hi,
>>
>> i run into a problem with uart. the small loop in the example produce an
>> echo at the 
>> uart. Uart is initialized in normal Mode without handshake and so on.
>> If i type in some characters in the terminalwindow all is ok. But if i
>> transmit short
>> strings from pc with full speed after a while the receiver isn´t working
>> anymore.
>> In debugger i can see that the sig_UART Interrupt is never called again.  
>>
>> when i put in the nutsleep instruction  it works for hours. 
>>
>>    NutRegisterDevice(&DEV_UART0, 0, 0); 
>>    com1 = fopen(DEV_UART_NAME, "r+b");
>>
>>    for(;;) {
>>   //   NutSleep(20);
>>      if ((c=fgetc(com1)) != EOF) {
>>        fputc(c,com1);
>>        fflush(com1);
>>      }
>>    }
>>
>> any help for this strange problem ?
>> ENUT 4.4.0  with Eclipse and openocd
>> Martin
>>
>