Not just RS-232 either. A few years ago I had two band decoders, and they would work fine on one LPT port but not on the other. Turned out the questionable port was only delivering 3.3 volts as logic 1, not quite enough for the band decoder.
73, Pete N4ZR The World Contest Station Database, updated daily at www.conteststations.com The Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com, spots at telnet.reversebeacon.net, port 7000 and arcluster.reversebeacon.net, port 7000 On 3/6/2012 12:36 AM, Jim Brown wrote: > On 3/5/2012 12:58 PM, Oliver Dröse wrote: >> you should*NOT* apply RTS directly to the GPIO pin! RS-232 levels go up >> into the ±20 volts region per specs > Not in recent recorded history! So-called RS-232 interfaces started > getting cheapened many years ago (before they went away and were > replaced by USB), and one of the first things to go was output voltage > swing. Think about the voltages available in a laptop, for example. I'd > be very surprised to see more than 10-12V on anything other than an > industrial RS232 interface, and less on most laptops. > > 73, Jim K9YC > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
