Product Description Pinout: 1) VCC external 3.3 V to 5 V voltage (which can be directly connected to 5 V microcontroller and 3.3 V microcontroller) 2) GND external GND 3) I/O external microcontroller IO port Please Note: Please ensure when purchasing this item that one understands the difference between active buzzers and passive buzzers. Below is the brief definitions of both. Note that the term "source" does not refer to the power source but to the shock source. Passive buzzers: 1) Passive internal without a shock source so a DC signal cannot make it sound. You must use 2K ~ 5K square wave to drive it instead. 2) For sound frequency control you can make "1234567" tone effect. 3) In some special cases you can use the LED as a control port. Active buzzers: 1) The active buzzer has a shock source within so long as a power is running. 2) For program control convenience a high and low level MCU can let the sound which a passive buzzer cannot do. Box Contains 1x Module
