: The main advantage of this board is the onboard AMS1117 3.3V regulator, which allows you to power the wireless module using a 5V supply (e.g., from an Arduino's 5V pin) instead of the strict 3.3V required by the raw nRF24L01 chip.
This is the most common configuration – active low. Check your specific module for an output LED indicator; when the LED lights up, the output is active (usually LOW). yl-105 datasheet
