@Rikko I’ll answer myself here. :) It might help someone else.

The problem was the version of Wiring Pi, which is a dependency to this module.
If you follow the instructions on this module’s page, you get version 2.50 of Wiring Pi. But that does not work with Raspberry Pi 4. You need 2.52.

Here you can find details:
http://wiringpi.com/wiringpi-updated-to-2-52-for-the-raspberry-pi-4b/

My DHT22 now works well with MMM-LocalTemperature. 👍

Picking up on an old thread.

I can’t get MMM-LocalTemperature to work on my Raspberry Pi4.

I have tried “all” variants I can think of in relation to pins (BOARD, WPI, Default, swithcing pins etc.).
But all I get is the “Loading” text.

Any ideas how I can troubleshoot? Can the C-file be run in some kind of verbose mode? Is these some kind of GPIO scan/test tool?

I’m using the DHT22 module, with pull-up resistor built in.
It can be faulty, I suppose. Can I verify its function somehow? I do not have logic analyzer or other such tools. Only have multimeter.

I’m a complete GPIO N00B/Rookie.