When it comes to measuring time on microcontrollers, there’s plenty of ways to go about things. For most quick and dirty purposes, such as debounce delays or other wait states, merely counting away a few cycles of the main clock will serve the purpose. Accurate to the tens of milliseconds, they get the average utility jobs done without too much fuss.
However, many projects are far more exacting in their requirements. When you’re building a clock, or a datalogger, or anything that relies on a stable sense of passing time for more than a few minutes, you’ll want a Real Time Clock. So called due to their nature of dealing with real time, as we humans tend to conceive it, these devices take it upon themselves to provide timekeeping services with a high degree of accuracy. We’ve compiled a guide to common parts and their potential applications so you can get things right the first time, every time.
After getting the VFDs lighting up and figuring out the circuitry on the back, [InThePartsBin] decided that a clock was the best thing to build out of it. It was decided that a specialized VFD driver chip was the easiest way to make the thing work, so a MAX6934 was ordered. To give the clock some brains, an ATmega328 was recruited and to keep time, [InThePartsBin] had some DS3231 real-time clock modules left over from a previous project, so they were recruited as well. A daughterboard was designed to sit on the back of the vintage board and hold the ‘328 and the VFD driver chip.
