With this shield the D1 Mini can be extended by a buzzer / acoustic signal generator. - Supply voltage: 5 V - Frequency: 1 ... 3 kHz - signal pin must be defined before use (D5 / D6 / D7 / D8) Pin assignment - 5 V: 5 V supply voltage - D5 / D6 / D7 / D8: signal pin - GND: Ground Note:Delivery includes 2 pin headers