sending bytes to parallel port

[H J van Rooyen]

"Timothy Smith" <timothy at open-networks.net> wrote:


| Grant Edwards wrote:
| > On 2006-07-28, Timothy Smith <timothy at open-networks.net> wrote:
| >
| >
| >> i've been trying to send an 8 byte string to my parallel port
| >> under freebsd. the purpose is it to control a relay board. the
| >> board simply responds to the output byte coming from the port.
| >> eg.  00000001 will set pin 1 high and flick the relay open.
| >> todate i've attempted this with merely open() on /dev/ppi0 and
| >> numpy for the byte array, but i just can't seem to get it
| >> working. i know the parallel port works and i know the relay
| >> board works (tested it with it's own windows ultility) so it's
| >> just my crappy programming keeping me from success.
| >>
| >
| > I'm guessing there's an implied request for help there
| > somewhere.  This would be a good start:
| >
| >   http://www.google.com/search?q=python+parallel+port
| >
| > I'd particularly recommend taking a look at the pyparallel
| > module found here:
| >
| >   http://pyserial.sourceforge.net/
| >
| > I've not used pyparallel, but based on my experience with
| > pyserial and some of Chris Liechti's other work, I'd bet
| > dollars to doughnuts it's your best option.
| >
| >
| yes, i did try pyparallel however it will not install on freebsd,
| setup.py errors.
|
| and yes i've done quite a bit of googling, i never expected it to be
| this difficult. i've done work with serial ports before. never parallel but.

What is on the other side of the link? - if its a small 8 bit micro - you may
simply be going too fast...

- Hendrik

|