1-wire sensor not detected in Evok web interface
Apologies for the newb question.
I am trying to use DS18B20 temperature sensors with an Axon L205 controller (using Evok and node-red). Currently I've got a single DS18B20 hooked up to the 1-wire port, and it doesn't show up in the web interface. I've tried connecting a couple of the sensors, none of them get detected.
I am not sure what further steps to take to diagnose the cause of the problem. Have I skipped some required configuration steps? I see that the evok.conf file has example entries for 1-wire devices but I am not sure if these are supposed to be auto-generated or if I am supposed to create them myself. Is there some way to manually scan the 1-wire bus for available devices?
Martin Kudláček last edited by
just to be sure, can you please post some photos of your sensor connection?
The first batch of sensors I tested this with came with wires and a casing, so I just attached the wires straight into the connector.
Then I also tested ones that just came as components with pins by placing them on a breadboard (the arduino shield has no significance, I am only using the breadboard glued onto it) In one of the images you can see the testing jig I used to verify that the sensors are giving temperature measurements on the breadboard. I did continuity checks to verify that there is a connection between the connector screws and the pins of the sensor.
I don't think it's a wiring issue. I suspect I might have messed something up during the installation of nodejs, npm and node-red, but I would like to know if there are some ways to diagnose the issue before trying something radical like reflashing the OS.
Do you see the other Axon inputs and outputs in the web interface, and if so, could you take a screenshot of it? The underlying stack for 1-Wire is quite simple - it consists of an OWFS server interface and an I2C 1-Wire adapter (with a device-specific hardware power switch, allowing it to be turned off/restarted independently of the rest of the system). While it is possible that the faulty behavior is due to a software issue, it's not the likeliest possibility in this case.
If you could also provide the output of a "sudo dmesg" command from the Axon SSH console it could potentially help us see if there is anything further going wrong.
All the other outputs and inputs are visible, and activating digital outputs in the web interface triggers them (or their status indication diodes, anyway).
I am not quite sure which parts of the dmesg output are relevant to the issue at hand so here is the entire thing:
(EDIT: apparently I pasted two successive outputs, here's just one)
Unfortunately the kernel log output looks fine to me.
Could you please post the contents of the SYSFS 1W folder '/sys/bus/w1/devices', i.e. ' sudo ls -la /sys/bus/w1/devices'? If you could also post the output of an 'lsmod' and 'ps fax' commands that would be very helpful as well, as I could then check if all the OWFS components are running correctly as well. I imagine they will be sizable, so a pastebin might be preferable again.
Apologies for the long debugging steps, but it can be quite difficult to track down an issue like this, since there is a large number of things that can potentially go wrong. However we do test each of our units with standard DS18b20 thermometers before shipping, and your setup does seem correct.
Here's the 1w device folder:
unipi@L205-sn7:~$ sudo ls -la /sys/bus/w1/devices total 0 drwxr-xr-x 2 root root 0 Dec 11 16:08 . drwxr-xr-x 4 root root 0 Dec 11 16:07 ..
unipi@L205-sn7:~$ lsmod Module Size Used by ds2482 16384 0 unipi 98304 6 wire 32768 1 ds2482 industrialio 53248 1 unipi at24 20480 0
Ok, after failing to diagnose the issue I ended up reflashing the OS and connecting to the controller through Mervis. I was able to reach the sensor without changing anything about my physical setup, which leads me to believe it was something I had done wrong during the installation of nodejs - which is not at all unlikely, since I kinda bodged my way to it after finding that the standard scripts in the links given would not work.
Glad to hear it's working - I'm not sure what exactly could have gone wrong, as everything seemed to be okay in the logs, which left me, well, quite clueless.
I was hoping to get back to you with some more information, but frankly could not think of any simple checks to be made. At any rate - I am very glad to hear that it is working for you now!