The version is 1.2, 555 Timer Free is a calculator to help you with your work, with 3 astable modes and monostable mode. Astable modes include duty cycle less than 50%, duty cycle equals 50% and duty cycle greater than 50%. Resistor and capacitor values can be tweaked. 1. 3 astable modes 2. monostable (one-shot) mode 3. duty cycle...