On Sun, 6 Jan 2002, John De Villiers wrote:

> Greetings
>
> Im in the process of trying to code a plugin for misim DE that does serial
> ( Receive ) comms. Transmit will come later, have to get my head around java
> first.
>
> Anyways, I can never remeber the polarity issue.
>
> When i use a pic ( 16f84 ) to talk rs232 via a max232 or similar level
> translator, does my "1" bit have to be ttl high or ttl low ?  I know the
> serial line uses high for 0 and low for 1 and idle is 0 ( high line states )
> and start is 1 ( low line state )
>
> Also, besides actually catching the transmitted bytes and displaying them
> what other "features" should i add to the plugin?
>
> I was thinking of :
>
> 1) Checking the pluse lenghts to check for possible overruns
> 2) Baud rate to be wholy user settable, even allowing rates that a PC cannot
> do )
> 3) Parity checking
> 4) Option to look for 9-bit addresses
> 5) Option to select transmission via max 232 type or "direct drive"
> 6) Any Speed Processor

I've written a module to do this for gpsim:
http://www.dattalo.com/gnupic/gpsim.html.

It's written in C++ instead of Java, but it might can serve as a starting
point. Check out the source in gpsim's CVS repository:

http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/gpsim/modules/

Unlike other gpsim modules, the usart module lacks a gui interface. As a
consequence it's somewhat difficult to use. For example, the bit streams
are dumped in ascii art (__--_-__-) and the byte streams are dumped as raw
hex. However, I've used it to actually debug the gpsim usart simulation
engine.

Scott

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu