Server Room Temperature Readings
I would like to monitor the temperature in the space where my pfSense machine is located. Is this something doable with a external usb temperature probe?
LAN port, PoE, SNMP, HTTP. Two inputs for external probes plus one integrated on board. ~30USD incl. one probe with ~1m cable
So the TEMPer and the TEMPerHUM seem to be popular but no support in FreeBSD….OpenBSD and NetBSD has uthum(4)
So does that use "One Wire Input Probes"? 30 bucks is reasonable. I like my APC goodies but everything is shrinking in size these days. Their PDU's and Environmental Units are really worthy…
Yeah. There's similar stuff to be found on eBay, see e.g. this one - even smaller, also has watchdog and other stuff.
Raspi + pilight software (pilight.org) + 433MHz (transmitter+receiver) + 433MHz temp/humidity sensor + (optional) 433 MHz-switchable power plugs (alternative: USB-switchable power plug)
You get a full remote-control (switch power on/off for various devices via your web browser) and temp/hum control for your server room and/or office… :-)
And it's fun stuff!
Try Voltcraft TCM 220 Digital Temperature Switching Module -30 to +70 °C. Has 2 channels with 2 probes. Has LCD, alarm treshold limits (too low and too high), local buzzer, serial port etc.
Works with two AA batteries, their lifetime is 3 years+ (mine are running for 4 years now, no low battery signs). It's got a serial output, which can be simply polled from a PC.
I wrote a Munin-plugin for this some time ago, works flawlessly in my room, one probe close to the floor, the other close to the ceilig, gaph plotting both:
I also like that it has an LCD, so whenever I go down to the room I can check the current values just looking at it (switching between the channels is done with a push-button).