TTN Node Below Zero

My TTN Nodes die after 0 Celcius. Since I live in the Arctic, this is a problem. I want to measure outside temperature. Once it gets to zero exactly, the unit seems to shut down.
Any ideas?
I tried to test the units in a freezer and it was the same for all units and a colleague is seeing the same issue. I would like to use the units in freezers to alert when they get warm.
I am also not sure how to calibrate the sensors. All three that I have in the same location have differing values. One is about 10 degrees higher than the rest.
Help appreciated.

You need to figure out how they dying and why. What part specifically is failing?

Batteries could be a likely one, you can devise ways to test that. Especially watch for them browning out under the power load of transmitting (or even receiving, which isn’t much less than transmitting at low/moderate power). There may be battery types more suited to cold weather.

Radio could go off frequency at temperature extremes

You could also have an invalid math operation that produces garbage (or in an extreme case even a system crash) when processing a measured temperature that hits zero or goes negative.

You need to add some serial debug logging, voltage measurement, etc to your node and identify the specific cause of failure. Try running wires into the freezer from an external power source.

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The TTN node uses a LoRaWAN module that stops working at zero degrees centigrade. To solve this you need to update the firmware of the module to the most recent version available on the Microchip website.
If you search the forum you should be able to find instructions on how to accomplish this.


Thanks! Will try that. We connected via USB in the freezer and batteries weren’t an issue. Glad to hear there is a fix. Will report back after locating and upgrading.