Nope, actually that persons overlay file is wrong. So yeah I don;t know
time to learn Linux and start troubleshooting your problems ;)

On Mon, Dec 5, 2016 at 8:47 PM, William Hermans <[email protected]> wrote:

> Actually the last bit probably wont work because:
>
> william@beaglebone:~$ ls /sys/devices/platform/ocp/*.gpio/gpio/
> /sys/devices/platform/ocp/44e07000.gpio/gpio/:
> gpiochip0
>
> /sys/devices/platform/ocp/4804c000.gpio/gpio/:
> gpiochip32
>
> /sys/devices/platform/ocp/481ac000.gpio/gpio/:
> gpiochip64
>
> /sys/devices/platform/ocp/481ae000.gpio/gpio/:
> gpiochip96
>
> You wont get an actual gpio bank number. Just the bank offset. So going by
> this beaglebone blogpost: http://www.bonebrews.com/
> temperature-monitoring-with-the-ds18b20-on-a-beaglebone-black/
>
> gpios = <&gpio2 13 0>;  /* P8.11*/
>
> I show P8.11 as gpio1_13 in my pinmux pdf file. So yes, 4.x versus 3.8.x,
> for gpio banks are definitely off by one. Looks like for 3.8.x kernel gpio
> banks start at gpio1, and I know for a fact that gpio banks in 4.x start at
> gpio0.
>
> Anyway, very good chance your overlay file is slightly wrong. Based on off
> by one gpio bank.
>
> On Mon, Dec 5, 2016 at 8:28 PM, William Hermans <[email protected]> wrote:
>
>> On Mon, Dec 5, 2016 at 7:30 PM, acheesehead <[email protected]>
>> wrote:
>>
>>> Tried your workflow today without success. Everything is OK up to the
>>> lsmod | grep w1 step. I only get the w1_gpio entry. I am not a Linux kernel
>>> expert, so I don't know how to troubleshoot why the other entries aren't
>>> showing up.
>>>
>>> I didn't see any activity on the oscilloscope either.
>>>
>>
>> Then, you must be using a 3.8.x kernel. Right ? But here are the modules
>> needed at least on a 4.x kernel:
>>
>> william@beaglebone:~/dev/bb.org-overlays$ lsmod |grep w1
>> w1_therm                4886  0
>> w1_gpio                 3764  0
>> wire                   35398  2 w1_gpio,w1_therm
>>
>> All three of those need to be loaded in order for the DS18B20 to work.
>> So, try manually loading those via modprobe. SO let's take a look at a rPI
>> blogpost: https://www.modmypi.com/blog/ds18b20-one-wire-digital-temper
>> ature-sensor-and-the-raspberry-pi
>>
>> Much of this blog post is going to be RaspberryPI centric. 
>> *dtoverlay=w1-gpio,
>> */boot/config.txt, etc. However if you scroll down to the *"Programming"
>> *part of the blog post. This person talks about loading the required
>> kernel modules( also note that kernel version is 3.6.11 ) Using modprobe.
>> So if you run those two modprobe commands, and then list the contents of
>> /sys/bus/w1/devices:
>>
>> *william@beaglebone:~$* ls /sys/bus/w1/devices/
>> 28-00000647ddf6  w1_bus_master1
>>
>> And you get output like the above. 1-wire *is* working, and the 1-wire
>> master ( beaglebone ) has detected a 1-wire slave device. It's working.
>> However, if you load both the above 1-wire kernel modules, and there is
>> nothing in /sys/bus/w1/devices, then something is wrong. I'd have to say at
>> this point, if you do not get an error about a missing module, that you
>> have your pin muxed incorrectly, or not properly connected to the pin.
>>
>> Now if you get an error on the command line from trying to load either of
>> those two 1-wire modules. Chances are pretty good you haven't compiled in
>> the given proper 1-wire support. In fact, I do believe there is a whole
>> section in menu-config for 1-wire devices. You may actually have to
>> recompile your kernel with support for the DS18B20 1-wire device . . .
>>
>> Another issues between 4.x, and 3.8.x kernels is that device enumeration
>> was different for some devices. So . . . It is entirely possible, in your
>> overlay, that the GPIO bank you're passing in as parameters is off by one.
>> How can be test for this ? On 4.x kernels . . .
>>
>> *william@beaglebone:~$* ls /sys/devices/platform/ocp
>> 40300000.ocmcram          48042000.timer
>> 480ca000.spinlock              49800000.tptc      driver_override
>> 40302000.ocmcram_nocache  48044000.timer
>> 4819c000.i2c                   49900000.tptc      modalias
>> 44e07000.gpio             48046000.timer
>> 481ac000.gpio                  49a00000.tptc      ocp:l4_wkup@44c00000
>> 44e09000.serial           48048000.timer
>> 481ae000.gpio                  4a100000.ethernet  of_node
>> 44e0b000.i2c              4804a000.timer
>> 481d8000.mmc                   4c000000.emif      power
>> 44e35000.wdt              4804c000.gpio
>> 48200000.interrupt-controller  53100000.sham      subsystem
>> 44e3e000.rtc              48060000.mmc
>> 48310000.rng                   53500000.aes       uevent
>> 47400000.usb              480c8000.mailbox
>> 49000000.edma                  56000000.sgx
>>
>> *william@beaglebone:~$* ls /sys/devices/platform/ocp/44e07000.gpio/gpio/
>> gpiochip0
>>
>> And the very first gpio address entry in this case was the lowest gpio
>> bank. So, if you investigate the equivalent directory in 3.8.x, you should
>> be able to check all gpio banks, to see what the actual lowest gpio bank
>> is. Do also keep in mind that /sys/devices/platform/ocp/ will be
>> different in 3.8.x. So you'll have to poke around a bit. Unless someone
>> else posts here and gives you the proper path. I don't remember what it is.
>>
>> Anyway, there is another option. You can upgrade your kernel to a newer
>> version. Which, yes, will probably mean you'll also have to either flash a
>> newer image, or run a newer image from sdcard.
>>
>
>

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