Mod

@Gilles-BILLARD I would like to think along to help, but lost you many posts back...
All was ok, so what did you change (and why) and what is the real issue right now?
And as @skywatch indicates, post the full log, sketch and everything. Don't try to filter information yourself, you might miss something.

@DenisJ you can just wait for the arduino to be in sleep mode to switch from mA to uA.

@WiktorDIY maybe the API and Documentation links on https://www.mysensors.org/download can be useful?
The Getting started guide can hopefully be useful as well.

Having a common plug for mA and µA range as the one you bought is the minimum, else you have to unplug/re-plug before the nodes gets out of sleep and obviously this will make measurement impossible. Unfortunately a lot of cheap multimeters have a separate plug and are useless in this scenario.

Best is to find a multimeter with more digits and that can use them all in the µA range. With 20 000 count you can go up to 20mA which is usually enough to measure power consumption for both sleeping and running node.

Welcome to the forum @WiktorDIY

https://www.mysensors.org/build/scene_controller LCD and keypad
https://www.mysensors.org/build/binary Button
https://forum.mysensors.org/topic/2169/wall-mounted-mood-light RGB led

You can connect everything to the gateway directly, no need for radio.

@DenisJ yes, it does not depend on the radio, but on the arduino platform

@DenisJ MySensors implements sleep() for AVR using the watchdog. As you know, the watchdog can only sleep for at most 8 seconds, so long sleeps are divided into smaller watchdog sleeps by MySensors. Sleeping for eg 30 seconds is divided into 3x8 seconds, 1x 4 seconds and 1x2 seconds. This is all done by the library, in the single call to sleep() without you needing to worry about it

@Gilles-BILLARD what pro minis are you using? The 3v3 version only goes to 57600 baud, so 115200 is likely too much

@evb said in Please give me an advice for a simple sensor node:

But the node will continue to work till 1.8V in a safe operating area.

Yeah sure, but alkaline batteries are nearly depleted when they get to 1V, so barely worth the hassle.

@DenisJ I would advise to just build the standard node as described. The 1MHz frequency will hardly increase battery life, if any, but possibly introduces new issues (eg new bootloader).
Your node will be sleeping over 99% of the time, so focus on sleeping current when trying to improve battery life.
Once you feel more familiar with mysensors and Arduino you could try out new improvements, but you can always return to your initial, known good sleeping node.