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Driver for 1-Wire sensor bus

  • I would like to connect temperature sensors DS18B20 to the Onion Omega via 1-Wire interface.

    Does anyone know how to setup and configure it?

  • @Omega303 If you run the following command on your Omega:

    • opkg list | grep 1-wire

    You will see quite a few available packages for 1-wire access including some for temperature sensors.
    Additionally it would appear that there are several packages relating to using 1-wire with the OWFS file system - see http://owfs.org/ and http://sourceforge.net/projects/owfs/ for information on OWFS

    Some of this may be helpful to you

  • Thanks @Kit-Bishop , I would love to use OWFS. But there seem to be no 1-wire related packages. opkg list returns nothing with 1-wire. (Omega Firmware 0.0.6 (b266))

    Shoud I expect this packages in the default firmware? Or can I add some missing packages via opkg install <package>

    What would be the correct package names? And which GPIO pin would be the data wire?

  • @Omega303 Before running opkg list did you run opkg update?
    This is needed for the Omega to get an up to date list of available packages. It should always been run after any system update. Doing so, I see 17 packages as listed in this file: 1-wire-packages.txt

  • Yes thanks @Kit-Bishop - opkg update revealed the w1-packages. And kmod-w1-gpio-custom looks promising. Unfortunatelly the dependencies can not be satisfied, since w1 packages require kernel 3.18.20 but the Omega already has kernel 3.18.23 after the update. Where can I adjust the dependencies? (The option --force-depends did not work and led to further issues.)

  • Anyone have any luck with 1-wire interface yet?
    I use DS18B20 sensors with arduino. I need sensors rated for up to 100C for my brewery project, so DHT11 or DHT22 are not an option. I would like to eventually run everything from the onion without an arduino dock.

  • Looks good - a friend of mine got the 1-wire interface up and running with the onion omega. But he had to compile the firmware all from scratch.

    I would rather like to stick with the original distro. But a dependency issue keeps me from installing the required package kmod-w1-gpio-custom

    opkg -A depends kmod-w1-gpio-custom

    kmod-w1-gpio-custom depends on:
    kernel (= 3.18.20-1-7bed08fa9c06eb8089e82c200340ec66)

    But checking the kernel

    opkg info kernel
    • Package: kernel
    • Version: 3.18.23-1-65008811ac4622ed020e0bf6384ece5a

    tells that the package requires an older kernel or the package dependencies need to be adjusted. Does anyone know how to get the package kmod-w1-gpio-custom installed?

  • administrators

    @Omega303 I can include it in the Omega firmware: gimme about an hour šŸ™‚

    EDIT: yikes, the openwrt build is having some issues. I'll try to resolve it tonight but it might have to wait until tmrw.

  • Thanks so much @Lazar-Demin for looking into it. I really appreciate your efforts.

  • administrators

    @Omega303 @Jonathan-Miller @Kit-Bishop
    Ok, I've sorted out the build issue.

    Run oupgrade -l -f to pickup b269, it includes the following kernel modules:

    • kmod-w1
    • kmod-w1-gpio-custom
    • kmod-w1-master-gpio

    Let us know how it goes!

  • Really great, thanks @Lazar-Demin the upgrade went well šŸ‘Œ
    The 1-wire interface seems to be initialized on the onion. But - shame on me - I missed the actual driver for the thermal sensors. The driver is included in kmod-w1-slave-therm
    Could you add this package possibly?

  • administrators

    @Omega303 no prob, its added in b270

  • Newbie here -

    I have a Gikfun DS18B20 sensor similar to the above (http://www.amazon.ca/gp/product/B012C597T0) -- I wired it like so: http://monosnap.com/image/HSxZm5p6mUS8iF5uvhtqgJxtScR7te

    From what I can tell I have the latest firmwire cited above:

    Firmware 0.0.6 (b270)
    Latest Firmware 0.0.6 (b266)

    My understanding is I need to figure out how to compile this: https://github.com/milesburton/Arduino-Temperature-Control-Library

    Any tips to get this compiled and get a reading? Or is there anyway to use the fast-gpio tool from onion?

  • @Omega303 what did you do to read with kmod-w1-gpio-custom?

  • Started to follow http://squidge.sourceforge.net/w1/ but I don't see a file named /etc/modules.d/<load sequence>-w1-gpio-custom to configure which pin is being used?

    Also, tried reading with fast-gpio but I'm just getting a reading on 0 - should I expect a reading from this?

  • āœ… SUCCESS Thanks @Lazar-Demin - for getting the packages for 1-Wire interface into the Omega firmware. šŸ˜ƒ 21.875Ā°C is the first temperature I read from a DS18B20 via Onion Omega. I am putting together a tutorial to document the steps needed to get the 1-Wire interface up and running. What is your preferred format? Is markdown sufficient?

    @Nathan-Bertram : You need the kmod-w1-gpio-custom to tell the 1-Wire interface to which GPIO pin you connect your data wire. Thats done by creating a file at

    • /etc/modules.d/55-w1-gpio-custom

    containing only one line:

      w1-gpio-custom bus0=0,19,0

    where 19 is GPIO pin (replace that number by the pin your sensor is connect to)

  • @Nathan-Bertram If the 1-Wire interface is set up and a device connected you can read by

     cat /sys/devices/w1_bus_master1/28-01234567890a/w1_slave

    where 28-01234567890a is the sensor id. This file only exists if all modules loaded correctly and an device is connected.

  • @Omega303 ok sweet - I got the w1 running it seems thank you! The sensor id folders keep changing with no w1_slave file present (which I assume means it keeps trying to detect my sensor but isn't getting data from pin 0 as I configured it. Do I need to put a resistor or does my current setup look correct (5V red, GND black and yellow pin 0) http://monosnap.com/image/HSxZm5p6mUS8iF5uvhtqgJxtScR7te ? (I checked the current I'm getting 5v which means I didn't totally botch the soldering job)

    root@Omega-088F:/sys/devices/w1_bus_master1# cat /etc/modules.d/55-w1-gpio-custom
    w1-gpio-custom bus0=0,0,0
    root@Omega-088F:/sys/devices/w1_bus_master1# ls -la /sys/devices/w1_bus_master1
    drwxr-xr-x    4 root     root             0 Jan 27 03:47 .
    drwxr-xr-x    6 root     root             0 Jan  1  1970 ..
    drwxr-xr-x    2 root     root             0 Jan 27 04:03 00-280000000000
    drwxr-xr-x    2 root     root             0 Jan 27 04:03 00-c80000000000
    lrwxrwxrwx    1 root     root             0 Jan 27 03:47 driver -> ../../bus/w1/drivers/w1_master_driver
    lrwxrwxrwx    1 root     root             0 Jan 27 03:47 subsystem -> ../../bus/w1
    -rw-r--r--    1 root     root          4096 Jan 27 03:47 uevent
    -rw-rw-r--    1 root     root          4096 Jan 27 03:47 w1_master_add
    -r--r--r--    1 root     root          4096 Jan 27 03:47 w1_master_attempts
    -rw-rw-r--    1 root     root          4096 Jan 27 03:47 w1_master_max_slave_count
    -r--r--r--    1 root     root          4096 Jan 27 03:47 w1_master_name
    -r--r--r--    1 root     root          4096 Jan 27 03:47 w1_master_pointer
    -rw-rw-r--    1 root     root          4096 Jan 27 03:47 w1_master_pullup
    -rw-rw-r--    1 root     root          4096 Jan 27 03:47 w1_master_remove
    -rw-rw-r--    1 root     root          4096 Jan 27 03:47 w1_master_search
    -r--r--r--    1 root     root          4096 Jan 27 03:47 w1_master_slave_count
    -r--r--r--    1 root     root          4096 Jan 27 03:47 w1_master_slaves
    -r--r--r--    1 root     root          4096 Jan 27 03:47 w1_master_timeout

  • administrators

    @Omega303 that's awesome! yeah, markdown would be great. let me know when it's ready and we can throw it into the Onion wiki.

    Or you can make a push request to the wiki repo directly: https://github.com/OnionIoT/wiki

  • @Lazar-Demin said:


    Is there a way how to check this ? I mean using a temperature sensor.
    I've been reading this post, and none of the folders / file exists on my Onion.
    Just updated to the latest version.

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