OWserver fails to start (502: Bad Gateway)

I’m a new Raspberry as well as HA user: Unfortunately I’m struggling with a setup utilizing DS18B20 1-wire sensor connected directly to GPIO4 on my brand new RP PI5.

I’ve installed Hassio lrybak/OWserver v0.6.1 from HA Add-ons.

When setting Device to ‘Fake’ everything works perfectly well and I am reading random temperatures from the fake sensor.

The issue is that, as soon as I change device to

devices:

  • device_type: w1
    owhttpd: true
    temperature_scale: Celsius
    device: DS18B20

the OWserver cannot start up but terminates after a while:

[11:28:11] INFO: Generated owfs.config file:
[11:28:11] INFO: # owserver configuration
'## device(s)
'### w1
server: w1
!server: server = 4304
server: port = 4304
http: port = 8099
'## temperature scale
Celsius
s6-rc: info: service owserver-init successfully started
s6-rc: info: service owserver: starting
s6-rc: info: service owserver successfully started
s6-rc: info: service discovery: starting
s6-rc: info: service owhttpd: starting
s6-rc: info: service owhttpd successfully started
[11:28:11] INFO: Starting owserver…
[11:28:11] INFO: Wait until owserver is up and running…
Terminated
[11:29:11] INFO: Starting owhttpd…
Terminated
[11:58:12] INFO: Successfully send discovery information to Home Assistant.
s6-rc: info: service discovery successfully started
s6-rc: info: service legacy-services: starting
s6-rc: info: service legacy-services successfully started

After a while I get the error message

502: Bad Gateway

in the OWserver (1-wire) window and I am not able to find nor read the physical sensor.

I am running the setup from Home Assistant OS:

Installation method Home Assistant OS
Core 2025.5.3
Supervisor 2025.05.3
Operating System 15.2
Brugerflade 20250516.0