low level device control

Greg Saunders lnx at telusplanet.net
Thu Aug 23 04:26:26 CEST 2001

First, let me state that I am a python newbie but absolutely love the 
language and am having a great deal of fun with it. Hail to the BDFL.

Here's the challage and I'm not exactly sure where to start.

I need to control two pairs of pin outs on a hardward device. The device 
has four pin outs. PIN1 sends a 12 volt pulse and is returned to ground 
via PIN2 if the two are shorted. PIN3 and PIN4 are either shorted, or 
not, putting the device in ready/not ready state respectively. The pulse 
on PIN1 needs to be read and counted (one count per pulse).

PIN1 - pulse
PIN2 - used to return pulse to ground if shorted

PIN3 - creates a circuit with PIN4 if closed
PIN4 - as above and puts the device into READY if shorted with PIN3

Here's what I want to do. I want to use python and a serial connection 
to read the pulses on PIN1 and be able to open and close the circuit 
programmatically on PIN3 and PIN4.

I can hack together a custom cable to tie into the harness.

My program knowledge is limited and my python knowledge is even more 
limited (but I'm learning quickly :-) but not quick enough). I've 
scanned throught the "termios" library reference but it does not appear 
to be what I'm looking for.

Any help would be much appreciated.

Greg Saunders

More information about the Python-list mailing list