I used to have a 555 timer program that was a free download years ago, and it was amazing, but it stopped working with windows years ago. I was able to put in my desired times and voltage, and it would do the math on the component values needed. Every single one I find now wants me to put in values to see the time. It's kind of frustrating. Is there still one out there that works like that? I am trying to do an Astable 555 that is close to 5 seconds on/30 seconds off at ~12V.