I want to effectively put a sensor into a very cold deep freezer by putting a probe into the freezer compartment, leaving the device's guts (importantly the power and the radio) outside the metal box. Does this exist?
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Two thoughts:
- Put a repeater right near the freezer.
- Run wires from the battery holder to an outside battery.
I've actually been running an https://www.amazon.com/gp/product/B01AKSO80O/ for a while now after I found the ST Multipurpose to be extremely unreliable. I've only got maybe 5 feet in the room to the nearest repeater and the signal is still wonky (a freezer is basically a Faraday Cage, duh). Does signal get out? YES! Is it as reliable as I'd like? No.
Similarly batteries in a deep frozen environment (-20C) don't function very well, so yeah, get the power supply outside.
This is certainly doable with a small amount of customization and I was just hoping that off-the-shelf parts exist, like the Qubino ZMNKID3 I didn't know about until now! Thanks
+1 for the Qubino. I have one measuring the temperature of my aquarium.
Works brilliantly.
I appreciate the idea, but the price tag is steep. The search continues, I think, for a reliable but more affordable solution.
I would go with a Fibaro Smart Implant with a DS18B20 temp probe inside the freezer, this will most likely be the best solution, not cheap but probably the most reliable and easy to setup!
See this thread...
Post 29 is my contribution. Been using that setup for over a year, might have changed the Zigbee module battery once. The temperature sensor just keeps on doing it's job.
Take a look at this:
GitHub - diyruz/flower: DIY Zigbee flower sensor
While it is intended to be a soil moisture sensor, is has the option of putting a Maxim DS18B20 1-wire temperature sensor ON A CABLE, with the intent of monitoring soil temps in greenhouses.
With this, the only thing that need go inside the freezer or fridge would be the sensor itself, and the other components can be outside the fridge.
The DS18B20 is claimed to have "±0.5°C Accuracy from -10°C to +85°C"
You can also connect the same sensor to a common hobbyist platform, the ESP8266, but that would be WiFi, not Zigbee
Connect DS18B20 to smartphone quickly and easily - Sensate (sensatio.io)
Nodemcu, konnected, ds18b20. Very, very cheap. Doddle.