Re: Controlling VFDs from your PC?

At 23:34 10/02/2002 +0000, you wrote:

>there are some serial & parallel port D/A and A/D projects at
>http://www.epanorama.net/links/project_pc.html#pc_parallel
>
>to save on the pin count you might bit-bang a serial bus on the parallel
>port and use ine of the serial loading D/A chips kinda like this one ,its a
>long URL and may wrap so cut-n-paste everything between the brackets
>[
>http://www.e-insite.net/ednmag/index.asp?layout=article&stt=000&articleid=CA170222&pubdate=10/11/2001
>]
>
>you can also run something like this from the serial port
>[
>http://archives.e-insite.net/archives/ednmag/reg/1997/030397/05DI_03.htm
>]

Of course, you could generate an analog output from one of the output lines
of the parallel port, by generating a PWM signal on the pin by software
means & feeding the output into a suitable R/C network. The output of the
network would then be a voltage varying between 0 and +X (where X is the
voltage on the pin when outputting a "1"), dependent upon the mark/space
ratio of the PWM output...

Regards,
Tony