I tried this git for info but it's outdated and uses slots: https://github.com/beagleboard/bb.org-overlays/tree/master/tools/beaglebone-universal-io
But my uEnv.txt file has the universal cape setting on by default anyways. config-pin seems to work on some pins but not others: I get this : sudo config-pin P9_26 i2c P9_26 pinmux file not found! bash: /sys/devices/platform/ocp/ocp*P9_26_pinmux/state: No such file or directory Cannot write pinmux file: /sys/devices/platform/ocp/ocp*P9_26_pinmux/state But some other pins it works. Missing pin mux data ? IDK how to check that or set it yet. On Tuesday, February 19, 2019 at 8:38:20 AM UTC-5, Charles Steinkuehler wrote: > > On 2/18/2019 9:21 PM, bruce...@gmail.com <javascript:> wrote: > > It's unclear to me so far why so many I/O pins are shared, creating > > exclusions, yet so many other I/O pins are left as simple GPIO. I mean, > > can't we have both two I2C and 2 SPI at the same time, all on different > > pins ? > > Use the I2C1 pins on P9.24 and P9.26 and you won't conflict with any > SPI pins. Load the universal cape and use config-pin to set the pins > to i2c mode. > > The core chip on the BBB (and just about _every_ non-trivial SoC) has > a lot of pin multiplexing to enable more features. The BBB suffers > slightly in addition due to the fact that not all pins are available > on the P8/P9 headers, further limiting options. A good reference for > the pin multiplexing is this spreadsheet (forked from selsinork, I > added details on pin usage for various CNC capes): > > > https://github.com/cdsteinkuehler/beaglebone-black-pinmux/blob/hal_pru_generic/pinmux.ods > > > ...and of course the AM335x data-sheet and TRM from TI. > > It can be frustrating trying to work through the various pin > multiplexing options, but it would be a *LOT* more frustrating not > having _any_ pinmux options! :) > > -- > Charles Steinkuehler > cha...@steinkuehler.net <javascript:> > -- 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/2dc3969f-2c23-4edd-8e3c-2eb7966cc449%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
