Closed
Opened by Gup @bobemoe

w1-gpio not showing devices on bus

On raspbian to get my dallas 1-wire bus working I need to add dtoverlay=w1-gpio,gpiopin=4 to /boot/config.txt and modprobe w1-gpio and w1-therm, then /sys/bus/w1/devices/ is created and contains all my w1 devices on the bus. The following is seen in dmesg: 

[    8.990310] Driver for 1-wire Dallas network protocol.
[    9.240792] w1-gpio onewire@0: gpio pin 4, external pullup pin -1, parasitic power 0
[    9.409546] w1_add_master_device: set_pullup requires write_byte or touch_bit, disabling

On devuan (raspi1) after following same process, the /sys/bus/w1/devices folder is created but is empty, and only the first line of dmesg above is shown.

We suspected missing packages so I searched for any gpio related installed on my working raspbian: python-rpi.gpio and python3-rpi.gpio where present on raspbian but not devuan so hopeful I installed from source https://pypi.python.org/pypi/RPi.GPIO (not available in devuan repo) but this has not helped.

Not sure if this is kernel or userspace issue? Any ideas where to look next?

  • parazyd
    parazyd @parazyd ·

    I've still to investigate this. Will check the kernel config and see if there is any mention of this.

  • Gup
    Gup @bobemoe ·

    Any luck with this issue? Do you think it could be related to #15 (closed) ?

    I did an experiment on my rasbian install and commented out the dtoverlay line from my /boot/config.txt and rebooted. I compared behaviour to that of devuan (but with dtoverlay) and its an exact match (only one line in dmesg and empty /sys/bus/w1/devices)

    This implies that the dtoverlay is not in effect, as described in #15 (closed) ?

    If I wok out how to build a kernel and confirm if it fixes or not would that help?

    I think I tried copying kernel and dto files from raspbian to devuan but cant remember the outcome now, other than it didnt help. Shall I try this again and report outcome?

    Or is this new info enough for a possible fix to be implemented?

  • parazyd
    parazyd @parazyd ·

    The overlays need to match the kernel being used. What board are you trying this on?

  • Gup
    Gup @bobemoe ·

    The board is Version 1 model B. The kernel and overlays are the ones included in image devuan_jessie_1.0.0-beta2_armel_raspi1.img.xz 13-Nov-2016.

  • parazyd
    parazyd @parazyd ·

    Any luck with the latest image? I bumped the kernel to 4.10

  • Gup
    Gup @bobemoe ·

    Awesome! Yes it appears to be working using the RC image. Many thanks :)

  • Gup @bobemoe closed ·

    closed