@loralg I successfully use a nRF24L01+PA+LNA on the gateway and regular nRF24L01+ on the sensors.

There is a lot of information and hints available in the forum regarding the nRF24L01+PA+LNA . See e.g. here:
https://forum.mysensors.org/topic/3719/nrf24l01-vs-nrf24l01-pa-lna/2

In my case, however, the nRF24L01+PA+LNA works fine without any fix or special attention.

With 2.1.1 I have the exact same problems.

However, everything seems to be fine with 2.2.0 Beta:

git clone https://github.com/mysensors/MySensors.git --branch development
cd MySensors
./configure --my-transport=nrf24 --my-gateway=ethernet --my-port=5003 --my-rf24-pa-level=RF24_PA_MAX
make

In domoticz:

The result:

pi@raspberrypi:~/MySensors $ sudo ./bin/mysgw -d
mysgw: Starting gateway...
mysgw: Protocol version - 2.2.0-beta
mysgw: MCO:BGN:INIT GW,CP=RNNGL---,VER=2.2.0-beta
mysgw: TSF:LRT:OK
mysgw: TSM:INIT
mysgw: TSF:WUR:MS=0
mysgw: TSM:INIT:TSP OK
mysgw: TSM:INIT:GW MODE
mysgw: TSM:READY:ID=0,PAR=0,DIS=0
mysgw: MCO:REG:NOT NEEDED
mysgw: Listening for connections on 0.0.0.0:5003
mysgw: MCO:BGN:STP
mysgw: MCO:BGN:INIT OK,TSP=1
mysgw: TSF:MSG:READ,2-2-0,s=1,c=1,t=0,pt=7,l=5,sg=0:24.0
mysgw: TSF:MSG:READ,2-2-0,s=2,c=1,t=1,pt=2,l=2,sg=0:58

After success with 2.2.0 Beta I tried to go back to 2.1.1. However, it still does not work.

I am on rpi3 and use a socket adapter board for the radio.

@breimann
I use remot3.it to provide remote access to domoticz running on a rpi3. It is very simple to set up.
It works great with a web browser on a pc. I did not test it with the domoticz android app yet.

I'm very interested in this too!

I have two Senseair K-30 CO2 sensor modules (http://www.co2meter.com/collections/co2-sensors/products/k-30-co2-sensor-module, http://www.senseair.com/products/oem-modules/k30), which use the non-dispersive infrared (NDIR) principle. The same principle is used in MH-Z14 as far as I understand.

The K-30 consumes quite some current and is not ideal for operation from batteries. However, my thougth is to connect it to batteries using a MOSFET, making it possible to switch on/off the sensor using an arduino output. Something like this:

In order to save battery the strategy is to:

• power up the sensor
• warm up for a few seconds
• take a measurement
• power down
• wait for some time (e.g. 10 minutes)
• start over again

The required warm-up time given in the datasheet is about 1 minute. However, a comparison of two K-30s - one powering up/down and the other powered on constantly - showed that a satisfactory measurement is obtained less than 10 seconds after powering up.

Any thougths on this issue will be very much appreciated.

@Boots33 Thank you!

Those posts provide lots of useful information.

@skywatch Thank you! That solved my problem.

Thank you all for your comments!

We ended up discarding the acer and bought an asus gaming laptop at a similar price.

So far my son is very satisfied.

Thanks @AWI! A level converter is exactely what is needed.

Arduino UNO can be perfectly well used. I use Arduino Uno for some of my mysensors. Connect VCC of the radio (NRF24L01+) to 3V3. Other pin numbers are the same.