In Monostable mode, also called One Shot mode, the output will be a single, short, positive pulse generated for a single input event. The duration is determined by the resistance and capacitance values of the circuit.
Formulas: T = 1.1 R1 C1
In Astable mode, also called Free Running mode, the output of the 555-timer will be a continuous rectangular wave output signal. The frequency and high and low times can be calculated based on the resistance and capacitance values of the circuit.
Formulas: TH = 0.693 (R1 + R2) C1, TL = 0.693 R2 C1, and F = 1.44 / ((R1 + 2R2) C1)
