I see that the minimum operating temperature is -10 C. What happens beyond that limit and where does that rating come from?
@Ewachlin, that temperature is most likely the lowest recommended operating temperature for one of the key components on the Tracker SoM (MCU, modem, GPS, etc.). What happens below this temperature is unpredictable and could range from erratic behaviour to being stuck in a boot loop and perhaps even being “frozen” (pardon the pun). It is also possible that nothing happens until the temperature hits -20 C though this might vary greatly from Tracker to Tracker.
Ok. If power usage was not a problem, would it be possible to work one of the onboard chips in order to purposefully create heat and use the thermistor to put a control loop on it to make sure it stays above -10 C?
Looking at using these where outside temperatures could get to -25F for short periods of time. They will be connected to an external power source so battery life isn’t an issue.
@Ewachlin, heating up a chip to produce heat is not a good idea. What is “short periods of time” defined as?
Typically, industrial applications use separate heaters, especially if you operate at -32 C. @rickkas7, do you or anyone you know have experience with this?
The minimum operating temperature of -10°C is only for the Tracker One, and it’s actually imposed by the case.
The Tracker SoM without a battery has a minimum recommended operating temperature of -20°C, but can operate down to -40°C with possibly reduced RF performance. You do need to be careful of condensation at very low temperatures, however.
@peekay123, ok that is fair. I wasn’t meaning quite warm, just enough to provide enough energy to heat the inside of the case. Short periods of time means several hours at a time.
@rickkas7, thank you for elaborating on this. What about the case can’t handle below -10°C?
The manufacturer of the case has a recommended temperature range. Presumably it gets brittle at very low temperatures, but I don’t really know for sure.