I tested the NodeMCU firmware on 4 ESP8266 modules and I have a problem with the WiFi range of the modules (only 8 meters).
I tried to switch to the Arduino ESP8266 core firmware and voilà, the modules have a better range (>12 meters). I think that NodeMCU doesn't set the ESP8266 to the maximum power.
I looked at the Arduino code and it contains a setOutputPower
method that set the RF power level of the ESP8266. How can I set this option in the NodeMCU firmware without modifying the firmware?