Does anyone know how I would go about emulating a parallel port on the Arduino? I would like to control a device that usually gets connected to a parallel port on a PC.
Steve
Its theoretically possible but I wouldnt know enough to do it.
You'll need to read a lot about the parallel port first.
What kind of device is it ?
Does it use alle the functionality of the Par. port ?
Many (non printer) devices was interfaced to the par. port using only the 8 data lines as digial outs, like the sequencer / interface combo i made for triggering circuit bend toys http://mikmo.dk/cbinterfacemain.html. If this is the case with your device it might be fairly easy to use the Arduino to do it.
But if your device use more sofisticated stuff on the par. port like bidirectional or EPP it might be impossible og very difficult.
MikMo
It's a pretty simple one-way galvo DAC
http://www.stephenhobley.com/DAC0832.gif
It looks like it would be a simple matter to hook this up - what do you think?
Steve
Well it seems to be using pin 1 - 9, 14, 16, and the ground pins 18 - 25.
Pin 1 is the strobe pin on the par. port, digital out
pin 2-9 are the 8 datapins also digital out.
pin 14 is autofeed, also digital out
pin 16 is Reset (or initialize) also digital out
For details look here:
http://www.lammertbies.nl/comm/cable/parallel.html
So it's using 11 digital outs, which should be possible with Arduino.
As far as i can see its generating 2 identical voltages in the 0 - 10 volt range with 8 bit resolution. Pin 2-9 are the 8 databits for the two DAC's and pin 14 and 16 are for writing the data to the DAC.
What pin 1 is doing is not so clear. Blanking ????
It's prpbably a good idea to check the DAC's datasheet for the timing of the signals.
Hope this helps
MikMo
EDIT: It might be outputting voltages in the -5 to +5 volt range, not quite sure.
Does anyone know how I would go about emulating a parallel port on the Arduino? I would like to control a device that usually gets connected to a parallel port on a PC.
I've actually got hopes for using an Arduino to emulate a parallel port to control a parallel device so I've been collecting links to various details on parallel port implementations:
http://code.rancidbacon.com/Electronics#ParallelPortInterface23
You might find some of the information linked useful. My overall impression is that it should be possible if you get the output timing etc correct. I'm not sure what precautions you'd need to take in terms of current usage etc but I seem to recall they use standard TTL voltages.
But it's all theoretical for the moment. 
You may want to consider using a 8- or 16-bit I/O expander for the implementation, see http://code.rancidbacon.com/LearningAboutArduinoMCP23S08 for details.
--Phil.