-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 12/27/2012 4:50 PM, Gene Heskett wrote: > Greetings; > > I have now spent several hours doing google searches, looking for a > chip that would be the reverse of a max232, so I can power this ttl > based sparkfun thing from what is available from the serial port. > There appear to be hundreds of variations on how to get from 5 or > 3.3 volt powered motherboards to a serial ports voltages, but > nothing to reverse that short of find an old ball mouse at a flea > market and stealing the chip out of it.
There is no special chip for this other than standard voltage regulators (or in many cases, a simple diode). In the old serial mouse days, the mouse driver would set some of the serial port handshaking pins to known steady-state levels and use those lines as a (low-current) power source to drive the serial mouse's LEDs and micro-controller. There's a reasonable write-up on the basics at this website: http://www.epanorama.net/circuits/rspower.html ...but there are lots of different ways to do this, depending on exactly what you need to power and how much current it's drawing. - -- Charles Steinkuehler [email protected] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAlDc8KkACgkQLywbqEHdNFw97wCfZBvlzP1prFVS6ritzzs1fkuV JcEAoMosTwiQ4lGF/W6zb0qWkqj1Z+gQ =fWdl -----END PGP SIGNATURE----- ------------------------------------------------------------------------------ Master HTML5, CSS3, ASP.NET, MVC, AJAX, Knockout.js, Web API and much more. Get web development skills now with LearnDevNow - 350+ hours of step-by-step video tutorials by Microsoft MVPs and experts. SALE $99.99 this month only -- learn more at: http://p.sf.net/sfu/learnmore_122812 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
