Hi there - can anyone help me locate the pin map spreadsheet for the X15 expansion headers (P16-P19)? Page 84 of the BeagleBoard X15 System Reference Manual suggests that this can be found on the X15 Support Wiki…
http://elinux.org/BeagleBoard:BeagleBoard-X15
…but I’m unable to find any links or references. All I can find is the schematic on page 27 of BEAGLEBOARD_X15_REV_B1.pdf
I have some experience with BBB but none yet with the X15 so I’m currently assuming that something like the SPI bus is accessible via GPIO pins set in some mode or other. I’m just having difficulty getting this information.
Thanks,
Dermot
Hi,
I don’t think the pinmap spreadsheet has been posted yet (http://beagleboard.org/discuss?place=msg%2Fbeagleboard%2FKAVSkC15EkA%2FlG4AHCoxCAAJ). A lot of this information can be found on TI’s website as well. I struggled with re-configuring the expansion header pins for a while, but I think I’m finally starting to get the hang of it.
But I THINK what really matters is the specific BeagleBoard-X15 image you are using (e.g. console, LXQT, etc) and the pinmux which has been incorporated into the u-boot image and kernel image (e.g. the device tree) associated with that specific beagleboard-X15 image. If you look at that pinmux configuration, then that will tell you exactly how the pins on the expansion header are configured for the image your BB-X15 is running.
Note: Most of the PINMUX for the 5728 is done within the SPL (per TI’s advice for the 5728 based on the glitch errata for the 5728). Only the MMC pinmux is supposed to be configured within the device tree per TI’s guidance. Note: I’ve configured/re-configured the pinmux for non-MMC peripherals within the device tree for testing purposes without it affecting me, but you should be aware of TI’s errata and the implications for your application and your hardware before determining that it’s ok to configure the non-MMC pinmux from the device tree…
Once you’ve located the correct pad configuration array in mux_data.h which your BB-X15 is actively using, then you can correlate the expansion header pinout on the BB-X15 schematic (page 27 on rev. B of the schematic) with the pinmux configured for the device. The first element of each of the rows in that array contains the M0 muxmode for each pad, so that will help you find which pad # each array element configures.
Then you need to look at the 5728 datasheet (and/or chapter 18 of the TRM) to determine the possible mux modes for each pad. This will tell you whether a GPIO line on the expansion header can be reconfigured as a SPI CLK line, for instance.
I hope this helps you get started… Let me know if you have questions, and I will try to get around to it when I can…
Thanks!
Jeff
One of the things I failed to mention is the support engineers on TI E2E helped me through some of my BB-X15/ 5728EVM expansion header pad configuration/pinmux issues. You can see the issues I was having and the steps the TI support engineer had me walk through to examine the pad configuration from user space on our BB-X15/5728 here:
https://e2e.ti.com/support/arm/sitara_arm/f/791/t/649900
Thanks…
Jeff
One of the things I failed to mention is the support engineers on TI E2E helped me through some of my BB-X15/ 5728EVM expansion header pad configuration/pinmux issues. You can see the issues I was having and the steps the TI support engineer had me walk through to examine the pad configuration from user space on our BB-X15/5728 here:
https://e2e.ti.com/support/arm/sitara_arm/f/791/t/649900
Thanks..
Jeff
EXP_CONN_PINLIST_B1.xlsx (523 KB)
Thanks!
I’m sure this will come in handy…
Hey Jeff & Gerald,
Thank you both for all of this excellent information. It’s great to be on the receiving end of real community support and to know that there are folks out there willing to share their experiences!
Much appreciated,
Dermot