Tuesday, December 17, 2013

Jaycar Digitech Wireless LCD Thermometer and Hygrometer (XC-0322)

After some clambering around in the roof space over the weekend I've decided it would be useful to get an idea of temperature and humidity readings from both the roof space and also sub-floor areas. I was hoping that the Jaycar Wireless LCD thermometer and hygrometer with options for up to 3 external sensors would do the trick.

Somewhat disappointed at initial inspection... I notice the box is actually mis-labelled 'Hydrometer' (a device for measuring specific gravity not humidity!) not a great sign from a quality perspective. Turns out the remote sensors only report temperature and not humidity (the latter being of most interest in terms of establishing whether to invest in electric ventilation fans for underneath the house). I find this somewhat misleading as the write-up suggests it is useful for monitoring a greenhouse remotely (where I really might want to be able to check humidity levels).

Accuracy wise, with both the base unit and 2 remote sensors sitting side by side on my desk, none of the sources agree on the current temperature (currently reading 25.1, 25.8 and 25.6 degrees celcius). The instructions suggest there is some method to manually calibrate to a known value but at this point I think I've lost faith in this other than as a novelty.

Another nuisance is the rubber seal around the battery compartment is a poor fit and jumps out of its groove whenever the compartment cover is removed.

It being Christmas there is certainly an opportunity for some regifting here of this admittedly modestly priced set up. Really I should be thinking about something a bit more hi-tech which will allow for ongoing data logging and analysis over the seasons - perhaps based on an arduino build. I guess you get what you pay for.


  1. I just bought this unit with two additional sensors and after pulling the batteries out of everything, working with a 60-second timer to syncronise checkins and doing sensor search both with power-on and the SET command I've yet to get it to connect to all three sensors :(

  2. Ah! 7th time lucky, got all three connected and they're all within 0.1°C of each other so I'm happy … kinda (until I have to replace the batteries and go through the process all over again)

  3. Hi Nathanael,
    I must confess I did end up popping these in someone's Christmas stocking to use in their greenhouse... Good to hear you've had a bit of fun with yours.