On Sunday 05 March 2017 18:42:45 Peter C. Wallace wrote: > > Question: For PCW: These pushbuttons have a separately wired led in > > them. If I can find 2 spare wires in the home switch cable, I could > > light them up to indicate the wheel is active. But the only note > > says to apply 1.3 volts. So whats the pullup current capability of > > a GPIO on the 7i90HD? > > > > I think I read only 3.3 volts is available, so thats a 2 volt diff > > to play with. Can I get 15 to 20 milliamps to run the led? That > > would mean a 100 ohm current limiter? Or is that in danger of > > cooking a GPIO? > > The FPGA pins will source/sink 24 mA without issue but source current > is limited in the 3V range by the bus switch turn off. If you want the > LEDS to be off at power up or watchdog bite its better to use active > low LED-ON FPGA outputs to sink LED currents. This also allows you to > tie the LED anode resistors to 5V (should be same 5V as supplies FPGA > board or pin 49 5V on a 7I90) With active low you get full 5V drive so > 220 Ohm or so would be about right > > > Thanks Peter. > > > > Cheers, Gene Heskett
Yup, I can do that too Peter, thanks. > > -- > > "There are four boxes to be used in defense of liberty: > > soap, ballot, jury, and ammo. Please use in that order." > > -Ed Howdershelt (Author) > > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > > -------------------------------------------------------------------- > >---------- Check out the vibrant tech community on one of the world's > > most engaging tech sites, SlashDot.org! http://sdm.link/slashdot > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users > > Peter Wallace > Mesa Electronics > > (\__/) > (='.'=) This is Bunny. Copy and paste bunny into your > (")_(") signature to help him gain world domination. > > > ---------------------------------------------------------------------- >-------- Check out the vibrant tech community on one of the world's > most engaging tech sites, SlashDot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
