On 2013-05-09, rafaello konfekte <[email protected]> wrote: > Hello, > > Could you share your experience with USB temperature sensors? I'm looking > for something cheap for my server room. Only one temperature sensor would > be fine, but internal + external temperature sensor and maybe even humidity > sensor would be even better. I'm looking for something that is supported by > OpenBSD sensors framework as that would be most convenient. > > Thanks! > >
"man -k sensor" will show you various options. "man -k sensor | grep ^u" for the directly USB-connected ones. The Toradex uoak* ones are now an open hardware design and Toradex no longer produce them themselves. 1-Wire sensors can also be connected to USB via uow(4), these may be a better bet if you want a larger number of sensors. At the moment most of the ebay vendors that I'm seeing have either ugold(4) or the TemperNTC version of uthum(4) devices. TemperNTC (http://www.pcsensor.com/index.php?_a=product&product_id=7) uses uthum(4) but has a problem where the sensor drops out occasionally; diff I posted to tech@ improves (but doesn't totally fix) this. This seems specific to TemperNTC, I don't have any other uthum(4) devices myself but it seems e.g. TemperHUM is more reliable. ugold(4) has not been committed yet, see recent tech@ posts. (http://www.pcsensor.com/index.php?_a=product&product_id=41) There are some possible races in the driver though in practice it seems to work well (better than the above TemperNTC). If you have something running, there are various ways to get graphs etc (snmpd in base exports sensor data; symon is another option), or for simple alerting you can just run sensorsd - I have it log to a separate file in syslog.conf: !sensorsd *.* /var/log/sensors and tell newsyslog to rotate the file without "log turned over" markers, and to send alerts: /var/log/sensors 644 7 * 168 ZMB root and uncomment the "send log file notifications" in root's crontab.
