Article View: sci.electronics
Article #5974Re: EVENT COUNTER
From: John Whitmore
Date: Sun, 02 Sep 1990 04:53
Date: Sun, 02 Sep 1990 04:53
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In article <26ded58a-39c.2sci.electronics-1@vpnet.chi.il.us> akcs.rick@vpnet.chi.il.us (fred salchli) writes: >More info about my problem . . . . . . . . > I'm attempting to build a BIG system, 144 or more channels and >building optical sensors would involve rewiring our facilities, and >refitting all our cages. A circuit which could clean or ignore the noisy >signal from the microswitch seems to be the easiest out. (relating to multiple counters running slowly; less than 10 Hz) Firstly, a microswitch has NO and NC contacts; an S/R flipflop can be connected with SET on 'NO' and RESET on 'NC' and there will be no bounce in the flipflop's output. This, however, adds a third wire to the switch connections. How about getting a large parallel port (boards with 144 inputs are probably not feasible, but three PC plugin boards with 64 circuits each would be suitable) and just strobing them in software? With a 60 Hz clock, add to a (software) counter every time a switch goes high for at least two consecutive cycles after being low for at least two cycles. The PC could even do something else in its spare time, if the clock were connected in interrupt fashion. I am known for my brilliance, John Whitmore by those who do not know me well.
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!samsung!dali.cs.montana.edu!milton!whit From: whit@milton.u.washington.edu (John Whitmore) Newsgroups: sci.electronics Subject: Re: EVENT COUNTER Keywords: counters,data aquisition Message-ID: <6992@milton.u.washington.edu> Date: 2 Sep 90 04:53:23 GMT References: <26dd5749-39csci.electronics@vpnet.chi.il.us> <26de96e2-39c.1sci.el <26ded58a-39c.2sci.electronics-1@vpnet.chi.il.us> Organization: University of Washington, Seattle Lines: 21