I decided to do something useful for myself today - I made a calculator for checking the timing of an LM555 in astable mode based on the resistors and capacitors used. The LM555 chip is one of the most useful chips out there as it makes sending a pulse train to a system incredibly easy. I am currently using one to control a stepper motor. My original plan was to use LabView; however, I realized that none of the DAQs we had in the lab were appropriate for controlling pulse trains.
The circuit is fairly simple, as is the calculation, but it is a pain to calculate all the values needed every time. I made a simple application in JavaScript, using jsfiddle, that calculates all the values I need with simple inputs. I again used a trick to not have to send any posts by merely calling a function after clicking on a fakeSubmit div.
The tool is up on jsfiddle here and below.