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Firing pins using serial lines RTS DTR

P: n/a
Hello:
I'm trying to use a serial port to activate a leds panel playing three
lines. I decided to do this way: one to send the data (RTS), another one to
use it as a data clock (DTR) and another one when the data frame has
finished (Tx with bit stop).

It works fine, but it is not quick enough. I can send about 50 bits every
millisecond using DTR and RTS, and using Windows CE it's worse. Maybe the
problem is in the api EscapeCommFunction, but I'm not sure.

How can I use these lines without any internal process, only to fire pins of
devices?
Should I use a parallel port?

Thanks in advance for your help
Best regards
Nov 16 '05 #1
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2 Replies


P: n/a
Jose,

If you write unmanaged code that uses the EscapeCommFunction, do you
still get the same slowdown? While there is little overhead in calling API
functions through the P/Invoke layer (about 7 extra instructions), it still
can add up, especially if you are running it in a tight loop.

Hope this helps.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"Jose" <je***@innovem.net> wrote in message
news:%2****************@TK2MSFTNGP15.phx.gbl...
Hello:
I'm trying to use a serial port to activate a leds panel playing three
lines. I decided to do this way: one to send the data (RTS), another one
to
use it as a data clock (DTR) and another one when the data frame has
finished (Tx with bit stop).

It works fine, but it is not quick enough. I can send about 50 bits every
millisecond using DTR and RTS, and using Windows CE it's worse. Maybe the
problem is in the api EscapeCommFunction, but I'm not sure.

How can I use these lines without any internal process, only to fire pins
of
devices?
Should I use a parallel port?

Thanks in advance for your help
Best regards

Nov 16 '05 #2

P: n/a
Jose,

you might want to give the serial components at
http://www.componentscience.net/Elements/TransPort/ a try. This could save
you lots of time and effort in the long run

Paul

"Jose" <je***@innovem.net> wrote in message
news:%2****************@TK2MSFTNGP15.phx.gbl...
Hello:
I'm trying to use a serial port to activate a leds panel playing three
lines. I decided to do this way: one to send the data (RTS), another one to use it as a data clock (DTR) and another one when the data frame has
finished (Tx with bit stop).

It works fine, but it is not quick enough. I can send about 50 bits every
millisecond using DTR and RTS, and using Windows CE it's worse. Maybe the
problem is in the api EscapeCommFunction, but I'm not sure.

How can I use these lines without any internal process, only to fire pins of devices?
Should I use a parallel port?

Thanks in advance for your help
Best regards

Nov 16 '05 #3

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