The 555 timer is a commonly used integrated circuit that can be configured to generate a square wave output. In the astable configuration, the output is a free running square wave output. In monostable mode, the output is a single high pulse generated for a single input event.
This app can quickly calculate the duty cycle (%), high level time (s), low level time (s), frequency (Hz) by inputting parameters such as R1 (ohm), R2 (ohm), C (F) )