**** BEGIN LOGGING AT Sat Mar 06 02:59:57 2021 Mar 06 08:57:41 I've copied BB-UART4-RS485-00A0.dts and modified it https://pastebin.com/UYMKX481 - I've tried to move the DE/RE (RSE) to P9.42, but it does not seem to work for me. I copied the modified file to /opt/source/bb.org-overlays/src/arm/ and ran the install.sh. The dtbo file turns up in /lib/firmware, and I've added "dtb_overlay=/lib/firmware/Waveshare-UART4-RS485-00A0.dtbo" in uEnv.txt. I also disabled Video, Audio, Wireless and ADC overlays. Scope does Mar 06 08:57:41 not see any change in RSE. What am I doing wrong? Mar 06 09:53:12 Trying to debug my RS485 DE/RE issue - Is it possible to see a pin is associated with an overlay? Mar 06 11:02:18 Running Linux beaglebone 4.19.94-ti-r42 (Debian Buster) - Do I need to download/configure/compile a new kernel to get BB-UART4-RS485-00A0.dts to work with DE/RE ? Mar 06 12:07:53 Knaldgas: the rs485 overlays were written for the old omap-serial driver Mar 06 12:08:02 they're not compatible with the 8250-omap driver currently used Mar 06 12:09:20 that driver does support rs485 mode though you simply disable that from userspace (although you still need an overlay but purely because cape-universal neglected to allow configuring uart rts/cts pins) Mar 06 12:10:14 and using a gpio for the DE signal instead of using the uart rts pin is not supported in kernel 4.x, it was implemented in 5.3 Mar 06 12:12:04 zmatt: Will the P9.42 be reasonable to use (the way Waveshare is connected) Mar 06 12:12:07 so if you want to use a different pin other than the rts pin for the uart, try installing a 5.4-ti kernel I guess Mar 06 12:12:24 P9.42 is not the rts pin for any uart Mar 06 12:12:28 https://pastebin.com/ENCBhyui Mar 06 12:12:58 Sorry, I misunderstood - I can easily rewire the board to whatever pin is better. Mar 06 12:14:39 Right, so using UART4 I re-wire the DE/RE to P9.33 Mar 06 12:15:19 my notes on rs485-related DT properties for both drivers: https://pastebin.com/7DKDZ0NP note that these can also be configured by userspace, or current actually *have* to be configured from userspace so you can actually ignore this document ;) Mar 06 12:15:47 you mean p8.33 ? Mar 06 12:16:03 Sorry, yes P8.33, thanks Mar 06 12:16:20 btw my overlay-utils ( https://github.com/mvduin/overlay-utils ) has an example overlay for this ("make uart4-rs485.dtbo") Mar 06 12:18:21 (caution: overlay-utils uses a different makefile and headers than bb.org-overlays for historical reasons, so don't carelessly mix the two) Mar 06 12:22:08 I'm in deep water here (not knowing much about BBB ,yet). Disabling the 8250-omap is just using /dev/ttyO4 right? Mar 06 12:22:28 ? Mar 06 12:22:59 (Probably not...) How do I disable 8250-omap from userspace as you suggest? Mar 06 12:23:07 I suggested no such thing and you cannot Mar 06 12:24:03 and /dev/ttyO4 is a symlink to /dev/ttyS4 for backwards compatibility (/dev/ttyO4 was the device name back then the omap-serial driver was used instead of the 8250-omap driver) Mar 06 12:24:49 Then I misunderstood, sorry. So I remove my RS485.dtbo and replace it with the one in your overlay util? Mar 06 12:25:21 yes, that should take care of the pinmux Mar 06 12:29:19 hmm, I just realized that since the rs485 properties in DT aren't supported yet, rts might be high until rs485 mode is enabled from userspace.... if this is indeed the case and if this is a problem for your application let me know, it can be worked around Mar 06 12:31:14 I have activity on the RTS now :-) - Just checking the schematics... Mar 06 12:36:35 bbl Mar 06 12:36:40 Right, DE/RE works now, thanks a bunch!!! - RTS is indeed held high during boot, but I plan on using the BBB as master it is probably not a problem. If it's easy to fix then of course Mar 06 12:38:01 my solution for that would be to make the pin runtime-configurable between gpio and rts (by customizing its pinmux helper instead of disabling it) Mar 06 12:38:18 which isn't too complicated, but I'm heading out right now, back later Mar 06 12:38:43 Thanks a lot for the help so far - I can get on with my project now :-D Mar 06 19:35:39 hi guys, I could use some help on compiling device trees for BBAI. I cloned the BeagleBoard-DeviceTrees github repo and tried building the default device tree ( am5729-beagleboneai.dts ). but the kernel doesnt start when I install the new dtb, even if I make no changes to the dts file Mar 06 19:39:04 by that I mean that I can see on the serial console that the boot sequence hangs right after "Starting kernel ..." Mar 06 20:08:18 cc: @lor Mar 06 20:08:27 > <@freenode_lolleren:matrix.org> hi guys, I could use some help on compiling device trees for BBAI. I cloned the BeagleBoard-DeviceTrees github repo and tried building the default device tree ( am5729-beagleboneai.dts ). but the kernel doesnt start when I install the new dtb, even if I make no changes to the dts file Mar 06 20:08:28 * cc: lorforlinux Mar 06 20:09:39 can we auto-ban people using that messed-up matrix(?) quoting? Mar 06 20:09:59 I'm sorry for that Mar 06 20:11:37 lolleren: make sure you select the branch matching the major kernel version used Mar 06 20:13:02 I did in fact use the wrong branch at first, since I'm at kernel version 4.14. But the problem persists even after switching to the correct branch Mar 06 20:13:56 odd Mar 06 20:32:21 14 Mar 07 00:47:34 Books? Read 'em! Mar 07 02:46:39 https://pastebin.com/raw/GvbwDr5m is something that may get your 'goat!' Mar 07 02:47:04 It is a funny saying from '49 from the almost extinct 'Popular Mechanics' Mag. Mar 07 02:47:24 I found it in a book. Mar 07 02:55:12 Oh and GenTooMan: Check this out >>> https://imgur.com/fLJwDvv . Mar 07 02:55:27 I got the truss rod installed w/ minimal destruction. Mar 07 02:56:09 I picked up some strings today from the local shop. I will be playing, "Devil went down to Georgia," before you know it. Mar 07 02:56:10 Ha. Mar 07 02:59:24 and, and, and **** ENDING LOGGING AT Sun Mar 07 02:59:56 2021