Overview

The PKM22EPPH4001 is a piezoelectric buzzer with a built-in oscillator circuit, requiring only a DC voltage to operate. It produces a loud tone suitable for alarms, notifications, and alerts.

The module features:

• Oscillation Circuit NOT built in
• Drive Type: External
• Operating voltage: 3V square wave
• Sound pressure level: ~85dB at 10cm
• Resonant frequency: ~4000Hz
• Low current consumption: ~3-30mA
• Simple 2-wire connection (+ and -)
• Compact 22mm diameter
• Through-hole mounting

Configuration Notes

• Requires single GPIO pin
• Can be driven directly from GPIO (for lower voltage versions) (NOTE check this, this is probably possible with LEDC Output)
• May require transistor driver for higher voltage/current
• Use ESP32 LEDC Output component for simple on/off control
• Use rtttl component for melodies
• It’s resonant at 4KHz, so it will be loudest around that frequency, but it can work reasonably well on other frequencies

Recommended driving circuit