I haven't gotten to attaching the LED and resistor across an GPIO pin. This is across the 3.3V power and GND. I hope the 12V supply can handle more than 20ma.
--Mark evilwulfie | Fri 28-Jul-17 10:28 AM your LED is trying to use too much current. a IO pin can source 3ma you need very low current LEDS On Friday, July 28, 2017 at 10:17:43 AM UTC-4, Mark A. Yoder wrote: > > I'm trying to wire an LED and 220 Ohm resistor to one of the GPIO pins on > the *GP0* connector of the Blue. > > > <https://lh3.googleusercontent.com/-WykVt-aNYGE/WXtGLlRncpI/AAAAAAAA1UU/2eJYlRootHYQ3sb36XLUgTPr-TxCZgyowCLcBGAs/s1600/GP0.png> > I measure 3.3V between the GND and 3.3V pins as I should, but when I hook > the resistor in series with the LED and attach them across GND and 3.3V, > the voltage across GND to 3.3V sags to 1.5V and the LED almost turns on. > (If I dim the lights in the room I can see a little light from it.) I get > the same result whether I'm powered off the USB, a 12V supply, or a LiPo > battery. > > How much current can the 3.3V supply deliver? It seems I should be able > to drive an LED from it. I can drive LEDs like this from the 3.3V supply > (and GPIO pins) on the Black. > > What's up? > > --Mark > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/8f26af4b-e54f-4f94-98bc-338ae1c4f05c%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
