You'll have to ask RCN, but it looks to me like all the pins were set to pull-down (except for the I2C pins, anyway). I was careful to match the power-on reset defaults, since I rely on some of those weak bias resistors to help insure hardware powers up in a "safe" state.
On 10/19/2018 11:11 AM, TJF wrote: > Thanks for the answer, Charles. In the default overlay it's PULLDOWN: > > https://github.com/beagleboard/bb.org-overlays/blob/master/tools/pinmux-generator/BeagleBone_Black.dts#L691-L693 > > And this is what anybody gets when not installing your cape universal > device tree blob. My question is still why? > > Am Freitag, 19. Oktober 2018 16:58:20 UTC+2 schrieb Charles Steinkuehler: >> >> On 10/19/2018 5:05 AM, TJF wrote: >>> With kernel 4.14.x on Beaglebone Black board (may Green and White as >> well) >>> after boot the pin P9_11 is in muxmode >>> >>> GPIO INPUT PULLUP >>> >>> , while the config-pin default is >>> >>> GPIO INPUT PULLDOWN >>> >>> Why that difference? Shouldn't the boot mode and the default mode be >> equal? >>> 13 further pins show that difference. >> >> The default mode for P9_11 is an input with pull-up enabled: >> >> >> https://github.com/cdsteinkuehler/beaglebone-universal-io/blob/master/cape-universal-00A0.dts#L392-L393 >> >> >> The default pin modes for cape universal were set to match the reset >> defaults of the AM3358, so loading the universal device-tree overlay >> would not cause any physical change in the pin state. The reset >> default states are listed in the AM3358 data-sheet (which is a >> different document than the AM335x TRM). Most pins are are generally >> GPIO inputs with either a pull-up or pull-down (pin dependent) after >> reset. >> >> -- >> Charles Steinkuehler >> [email protected] <javascript:> >> > -- Charles Steinkuehler [email protected] -- 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/dc33d104-5fc3-6a43-f3fb-872f65b93b30%40steinkuehler.net. For more options, visit https://groups.google.com/d/optout.
