Building the first system. Got all the hardware and around 0,1 knowledge in arduino and esp. So currently facing an issue - which one is a better way to go and learn as i couldn’t find any pros cons comparsion except for power consumtion. Seems nrf is better documented through mysensors.
Currently in need of 4 sensors consisting of DHT22 + MQ5 + MQ7 e.t.c binded somehow to openhab
I’ve been weighing up the pros and cons of both of these too. As you suggested the power issue is certainly the biggest, but is only really a problem for battery powered sensors. That said, my calculations seem to indicate that you should be able to get 2-3 months out of a couple of AA batteries with an ESP8266 reporting sensor data every 5 minutes. An nrf24 based system will go for >1 year on the same batteries.
Network/RF interference and range is also an issue. The 2.4GHz band is notoriously clogged and the 3 non-overlapping channels give limited options. The ESP which is furthest away from the AP in my house is totally swamped by surrounding APs but still works reasonably well - I still have to monitor it closely though, which somewhat defeats the point. I’m intending to mitigate this by adding another AP for that part of the house. I’m not sure how well the nrf24l01 modules will perform in such an environment. I have some to try out but haven’t got around to it yet - I have heard that the quality and range varies significantly between modules.
If you go the nrf24 route you will also need some base station/bridge and will need to handle two protocols (one across the RF, one to OH). In contrast the ESP8266 can use MQTT which is pretty much idea for integration into OH.
In short I would prefer the ESP route if only the power consumption wasn’t so high! I still need to do some experiments here to see if my calculations line up with reality.
I’m using the ESP to integrate with my alarm. I can get 5V off (and the ESP8266 board I’m using can bring this down to 3v). Personally it fits my needs nicely.