Ethernet connected temperature sensors?

[formal oar]

Looking for a decent wired solution for measuring temperatures in a server room that isn't overpriced as heck. Usb powered would be nice as I don't really want to have to replace batteries every couple months.
Since it's a server room anything wireless won't really be all that reliable - especially if I want to place a sensor inside a rack - so I'm looking for something that just takes ethernet.

I've tried googling some but I keep ending up with expensive equipment (100 bucks plus) and I was hoping there's still some cheap solutions out there

[fresh harness]

You could try some esp + poe and diy a temp probe onto it

Coud imagine that m5stack should have something for that

[deep mason]

I know you're not a fan of wireless, but have you considered an ecowitt weather station with sensors that have external temp probes? I use the probes for aquariums and change them out maybe once a year(2 AA batteries) Depending on your location the probes are at a lower frequency so range should be much better(915MHz for North American; 868MHz for Europe; 433MHz for Australia and other areas) https://a.co/d/b2ocFHG and https://a.co/d/1Qmucmp

[formal oar]

biggest problem with wifi is that the server room is effectively a faraday cage with all the metal stuff on the walls and ceiling

[formal oar]

never heard of that m5stack before, looks neat

[deep mason]

the wifi part is irrelevant on the hardware I linked as the box main box can be placed outside the server room, the 915 frequency would penetrate better then 2.4 at least. Just offering an out of the box idea

[formal oar]

huh, good point

could probably wire the sensor through the ceiling in that case

[deep mason]

nice part is they are cheap, and expandable, 8 temp sensors on the one control box

[calm halo]

a esp32 poe dev board and a temp sensor would be a route definetly.
also craftcomputing is making a device to do this (some beta versions were sold but its not ready yet) https://www.craftcomputing.com/