On Thu, Feb 15, 2018 at 1:48 PM, <[email protected]> wrote: > I am trying to implement the 1-Wire protocol to read a DS18B20 temperature > sensor on the PocketBeagle. So far I have been able to correctly read the > temperature on a BeagleBone Black (BBB) using the following guide: > > http://www.bonebrews.com/temperature-monitoring-with-the-ds18b20-on-a-beaglebone-black/ > > I changed the .dts file below to use the same GPIO port on the BBB (P8.11 - > GPIO45) as on the PocketBeagle (P2.33 - GPIO45) on line 19 and added the > missing semicolon on line 37. I checked the GPIO offset for both of these > pins and they are the same, so it should be the same signal. > > /* > * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/ > * > * This program is free software; you can redistribute it and/or modify > * it under the terms of the GNU General Public License version 2 as > * published by the Free Software Foundation. > * > * Modified by Russell Senior from the weather cape's DTS file. > * Minor formatting by C W Rose. > */ > /dts-v1/; > /plugin/; > > > / { > compatible = "ti,beaglebone", "ti,beaglebone-black"; > part-number = "BB-W1"; > version = "00A0"; > > > exclusive-use = "P8.11"; /*changed to P2.33 for PocketBeagle*/ > > > fragment@0 { > target = <&am33xx_pinmux>; > __overlay__ { > bb_w1_pins: pinmux_bb_w1_pins { > pinctrl-single,pins = <0x34 0x37 /* gpmc_ad13.gpio1_13, > OMAP_PIN_INPUT_PULLUP | OMAP_MUX_MODE7 - w1-gpio */ >; > }; > }; > }; > > > fragment@1 { > target = <&ocp>; > __overlay__ { > onewire@0 { > status = "okay"; > compatible = "w1-gpio"; > pinctrl-names = "default"; > pinctrl-0 = <&bb_w1_pins> /*missing semicolon here!*/ > > > gpios = <&gpio2 13 0>; > }; > }; > }; > }; > > > However, when I try to use the same procedure on the PocketBeagle (which is > running Ubuntu), I run into a problem when trying to load the overlay. The > guide I have been following uses the capemgr.9 for the BBB, which is not > supported by the PocketBeagle. I then tried to load the overlay using the > uEnv.txt file to load the overlay (.dcbo file located in /lib/firmware/) at > boot. I uncommented the master enable and Overlay 1 lines and replaced the > "file" placed holder with the .dcbo file name. > > After attempting the reboot the PocketBeagle to load the overlay, the > PocketBeagle gets stuck during its boot procedure and fails to fully boot > and have to reflash the SD card to boot the device; I believe this is due to > trying to load the overlay. > > Therefore I have a few questions: > > Is there information in the above .dts file that is causing this error? > Is changing "P8.11" to "P2.33" supported by the PocketBeagle? > Are there any other steps I am missing to load the overlay using uEnv.txt?
Give this a shot: https://gist.github.com/RobertCNelson/dfd4f707a89b83c9366ecfcdc24321b0 In fragment 0, we drop the cape-universal pinmux for P2_33, this free's up the pin for dedicated functions. In fragment 1, no change In fragment 2, &gpio2 -> &gpio1 Regards, -- Robert Nelson https://rcn-ee.com/ -- 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/CAOCHtYji%2Bze0yXTmU1Adg9Pg01BwvU%2B31VwnYyfttRMwYYUBTA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
