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Unread 08-07-2005, 12:06
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Mike Betts Mike Betts is offline
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Re: TTL port to a serial port on a demo board

In your code example, you are hanging because the queue is full. It will not empty unless there is communications established.

Level shifting: TTL is a 0V to 5V signal. RS232 is usually -12V to +12V. You can not just wire the two together without some sort of level shifter (see Fowlerm's post).

Printf: Indeed, printf statements output a string (the f in printf stands for formatted). I would avoid sending binary (unformatted) data until you have your system well established and debugged. Without a serial protocol analyzer, debugging unformatted communications is very difficult.

JMHO

Mike
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Mike Betts

Alumnus, Team 3518, Panthrobots, 2011
Alumnus, Team 177, Bobcat Robotics, 1995 - 2010
LRI, Connecticut Regional, 2007-2010
LRI, WPI Regional, 2009 - 2010
RI, South Florida Regional, 2012 - 2013

As easy as 355/113...