Lpc2000

Thanks everybody,

I used solution with timer. I have 2 serial link with two RS485 possible. So 
i use timer 1 with two Match Register (MR0 and MR1).

Fisrt I calculate time for one character tranmssion  (TimeCar). When my 
transmitter is empty i program MR with the value TC + TimeCar and i activate 
IT timer.

In the IT timer i turn back in reception.

void TIMER1_irq ()
{

  // Test du registre MR0 du timer1
  if ((T1IR & 0x01)==0x01)
  {
    T1IR |= 0x01;
    if ((T1MCR & 0x01) == 0x01)
    {// MR0 activé et actif
      T1MCR &= ~0x01;
     // On descend RTS
     vTransmissionRs485(0, OFF);
    }
  }

  // Test du registre MR1 du timer1
  if ((T1IR & 0x02)==0x02)
  {
    T1IR |= 0x02;
    if ((T1MCR & 0x08) == 0x08)
    {// MR1 activé et actif
      if ((U1LSR & 0x40) != 0x40)
        GEN_TraitErreur();
      T1MCR &= ~0x08;
      // On descend RTS
     vTransmissionRs485(1, OFF);
    }
  }


/* Only a part of my UART IRQ to not lose you */

      if (pSer->bRs485 != FALSE)
      {
        if ((*(pbReg + OFF_LSR) & 0x60) == 0x20)
        {// If THR Empty and Shift register not empty
          // We activate timer
          *pSer->MR = T1TC+pSer->dMatchReg;
          T1MCR |= pSer->bValItTimer;
        }
        else
          if ((*(pbReg + OFF_LSR) & 0x60) == 0x60)
           vTransmissionRs485(1, OFF);// No more transmission
      }






----- Original Message ----- 
From: "Peter Jakacki" <peterjak@...>
To: <lpc2000@yahoogroups.com>
Sent: Monday, September 19, 2005 3:29 PM
Subject: Re: [lpc2000] RS485


> Gilles,
> If you don't disable the 485 receiver or the UART rx itself you can
> monitor the bytes that are transmitted. There are variations on this
> scheme but it means that you could simply turn off the 485 transmitter
> when you receive the last character that you transmitted.
>
> Also, as Grzegorz pointed out you could use a timer, that is if you have
> one to spare.
>
> Both of these are practical real-time solutions and easily implemented.
>
> BTW, Yves sample code seems to be switching the PINSELs which has got to
> be totally redundant and unnecessary. Just keep the rx and tx alive and
> you only need to drive the 485's TE pin.
>
>
> Gilles FAURIE wrote:
>
>>Yes i could do that but i don't want to wait in my interruption routine
>>during character transmission which could be about 1ms (at 9600 baud).
>>
>>
>>----- Original Message ----- 
>>From: "Yves Rondeau" <op173039@...>
>>To: <lpc2000@yahoogroups.com>
>>Sent: Monday, September 19, 2005 11:17 AM
>>Subject: RE: [lpc2000] RS485
>>
>>
>>
>>>Hello ,
>>>
>>>I had the same problem on ISO7816 communication.
>>>At the end of TX I switch back in input mode then lost the 2 last bytes.
>>>
>>>Add those lines at the end of your TX routines
>>>
>>>while (!(U1LSR & 0x40));   /* Wait if U1THR & U1TSR not empty */
>>>
>>>
>>>    /* we need to wait for the 2 Tx Buffer */
>>>   /* to be empty */
>>>   /* or we can lost the 2 bytes switching
>>>*/
>>>   /* in input */
>>> PINSEL0 = 0x00040000;    /* RX UART1 Enable -TX Disable */
>>>
>>>
>>>
>>>Yves
>>>
>>>-----Original Message-----
>>>From: lpc2000@yahoogroups.com [mailto:lpc2000@yahoogroups.com] On Behalf
>>>Of
>>>gfaurie1
>>>Sent: segunda-feira, 19 de Setembro de 2005 7:44
>>>To: lpc2000@yahoogroups.com
>>>Subject: [lpc2000] RS485
>>>
>>>Hello,
>>>
>>>I try to develop a RS485 driver, but i have a problem.
>>>
>>>As you know, you must stay in reception and when you have to transmit,
>>>you change direction to be in transmission only during transmission.
>>>When the last character has been transmitted you turn back in
>>>reception.
>>>
>>>Problem is that i have no interruption on shift register empty. I have
>>>an interruption when transmitter is empty but if i change direction at
>>>this time, character which is in shift register is not transmitted,
>>>and i lose it.
>>>The only solution that i suppose is to check state of shist register
>>>(LSR) in polling but i'd like to find a more real time solution
>>>
>>>Who can help me ?
>>>
>>>Thank
>>>
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