I live in an area with very mild weather year-round. It’s generally between 15C and 25C. On rare extreme days, between 5C and 40C.

I made one of these for a family member that lives in much colder weather (winters regularly have days that don’t get above -30C), and it did not do well there either. Ended up putting the ESP8266 in the garage (which stays above 5C), and snaking the probe outside.

In my experience, PlatformIO is a strictly superior development environment (and by a vast margin). There are pre-compiled binaries if you don’t want to set it up 🙂

If you do much Arduino dev at all, pio is definitely worth setting up.

Reporting temperatures in Celsius wouldn’t be difficult. Change would be here:

https://github.com/sidoh/esp8266_thermometer/blob/master/lib/TempIface/TempIface.cpp#L33

Voltage is read from the only Analog pin on the ESP8266 — A0:

https://github.com/sidoh/esp8266_thermometer/blob/master/src/main.cpp#L49

you can read more about A0 here:

https://randomnerdtutorials.com/esp8266-adc-reading-analog-values-with-nodemcu/

you’d have to connect Vin from your power source to A0 in order to read voltage (keep in mind that you’ll need a voltage divider if maxV is > 3.3v).

Could you also ,please explain the Voltage parameter,, mine changes from 2 to 1 ,, and decimals also not constant,, sometimes 4 sometimes 2,(possible connection error?) I would love to get e.g. 25.28 only, thanks,,

Hi Martin, I doubt we could find a way to make it work. While it’s not hard for me to assemble stuff like this, it takes me a long time.

It’s a good question.

The D1 Mini — and every other dev board I’ve used — has a built-in voltage regulator. As long as you supply the Vin pin, voltage will be regulated down to 3.2v.

You probably are better off with a buck converter, though. The built-in regulators are basically always linear regulators, which are far less efficient than buck converters.