The nRF24L01 is a 2.4G Wireless Digital Audio Module DC-5V 44.1K Sampling rate 24bit AD sampling to achieve nondestructive high-fidelity digital audio transmission 16-channel selectable distance 100 meters on open ground.
This is an Active buzzer is present inside with shock source, so as long as the electricity will call 2 Program control convenient, single chip microcomputer a high and low level can make the sound, and the passive buzzer is can not do.
PIC16F877A Development Learning Board PIC USB Programmable MCU Controller System Core Board Module HJ-5G Experimental Platform Description: PIC16F877A Development Learning