Lpc2000

Hi,
I'm searching for implementing RS485 using UART1 and controlling TX 
enable with RTS pin. Is it possible to use UART hardware module to 
control pin RTS during transmission without have to set/clear a GPIO 
pin connected to /RE or DE every time I start transmission or and 
transmission???

Thank you to everyone in advance for interest.

Dalla Mariga Enrico

--- In lpc2000@yahoogroups.com, "gvnn77" <paynet@l...> wrote:

> I'm searching for implementing RS485 using UART1 and controlling TX 
> enable with RTS pin. Is it possible to use UART hardware module to 
> control pin RTS during transmission without have to set/clear a
> GPIO pin connected to /RE or DE every time I start transmission or
> and transmission???

No.  There is no advantage of using the UART1 RTS pin rather than a 
GPIO pin.  And you cannot even make the UART generate an interrupt
when the last stop bit has been sent and it is time to turn off the 
transmitter.

Karl Olsen

How would you implement an interrupt based 485 handler then? I guess I
could look for the byte that I transmitted. Hopefully the FIFO won't
complicate issues.


--- In lpc2000@yahoogroups.com, "Karl Olsen" <kro@p...> wrote:

> --- In lpc2000@yahoogroups.com, "gvnn77" <paynet@l...> wrote:
> 
> > I'm searching for implementing RS485 using UART1 and controlling TX 
> > enable with RTS pin. Is it possible to use UART hardware module to 
> > control pin RTS during transmission without have to set/clear a
> > GPIO pin connected to /RE or DE every time I start transmission or
> > and transmission???
> 
> No.  There is no advantage of using the UART1 RTS pin rather than a 
> GPIO pin.  And you cannot even make the UART generate an interrupt
> when the last stop bit has been sent and it is time to turn off the 
> transmitter.
> 
> Karl Olsen