I think that since you're getting power from the P9 header for this circuit, you're ok. As far as isolation goes. But again I'm not an EE so someone who is should answer that question. I'm a software person too.
I also see what seems to be a current limiting resistor . . . As far as the LED always being lit, but dimmer when toggled low. Your transistor is always conducting for some reason. Maybe a weak pulldown on the gate is needed ? But hey. software guy, not electronics guy here . . . On Mon, Oct 24, 2016 at 7:25 PM, mzimmers <mzimm...@gmail.com> wrote: > Oh, now this is interesting: now that daylight has gone, and the room's a > little darker, I can see that the LED is on brightly when the value is 1. > When the value is 0, it's noticeably dimmer, but not completely off. > > Here, I'm way out of my depth (I'm a software person)...I double-checked > the resistor, and it's the correct "size" (220 ohm). > > I remember reading in the book that the BBB is a little "fussy" about > things getting connected an disconnected. Is it good practice to do a > shutdown before I start moving wires around for testing? > > Thanks.. > > mz > > On Monday, October 24, 2016 at 7:32:59 PM UTC-6, William Hermans wrote: >> >> I'd check /sys/class/gpio/gpio49/direction . . . >> >> william@beaglebone:~$ cat /sys/class/gpio//gpio49/direction >> in >> >> Make sure its "out" >> >> After that, I'd start by disconnecting P9.23 from the circuit, then check >> with a volt meter that the pin isn't somehow damaged. P9.1 and P9.2 are >> both ground on that header. >> >> >> -- > 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 beagleboard+unsubscr...@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/ > msgid/beagleboard/2fa711fd-f6e3-4aa2-a7cb-d74f395c6450%40googlegroups.com > <https://groups.google.com/d/msgid/beagleboard/2fa711fd-f6e3-4aa2-a7cb-d74f395c6450%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- 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 beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CALHSORocr3GNu-8ynS9GQ_8dyBCc1R2%2Bbi-91LVx4-1MATNSDA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
