SN74121N Monostable Multivibrator UART To TTL Converter You can also consider 5W-8Ohm

You can also consider 5W-8Ohm Speaker

Sinks or sources 8 mA at VCC = 4

In Controlling Heavy loads at a pre-determined time/condition

0 BLE Module

The Sensitivity of Digital pin can be varied using the potentiometer

SN74121N Monostable Multivibrator UART To TTL Converter You can also consider 5W-8OhmThe SN74121N is a monostable Multi vibrator with Schmitt trigger inputs features dual negative transition triggered inputs and a single positive transition triggered input which can be used as an inhibit input. Complementary output pulses are provided. Pulse triggering occurs at a particular voltage level and is not directly related to the transition time of the input pulse. Schmitt trigger input circuitry (TTL hysteresis) for the B input allow jitter