On Mar 1, 2009, at 9:39 AM, Olin Lathrop wrote:

> I understand what [DCC] is ... However, the OP was asking about data  
> from a serial port from a PC, which has nothing to do with DCC.  I'm  
> thinking the OP understands neither RS-232 nor DCC nor that the two  
> can't just be interchanged.

I think it makes a lot of sense to prototype the motor drive code that  
the OP is asking about with a "simpler" communications channel in  
front of it (rs232 serial instead of DCC.)  After the packet handling  
and motor chip control is working ok, you can "drop in" a known  
working DCC module in place of the rs232.

I do things like this all the time, all the way up to compiling  
microcontroller C code under linux and running it in a mode where what  
will eventually be pin inputs is provided via keyboard or debugger.   
It's very useful.

All that said, it ISN'T clear that this is the sort of thing that the  
OP has in mind, but I don't THINK any of his questions are about the  
protocol design, either?  Improved clarity in the questions would be  
nice, but we don't have to go off chasing non-issues either...

BillW

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