After creating the simplest nightlight possible (but with very neat functionality) using just a single PICAXE 08M2 chip and an LED, I became intrigued by what else I could do with a minimum of components. A clock using a single-bit input and single-bit output seemed like the natural progression.
Sure, an accurate clock using a DS1307 as a timebase, and a few pushbuttons for input would be a good project for an afternoon, but the limitations of just a bare PICAXE were too tempting to resist. And here is where I started to sink way too much time into this project. There is a good reason that real-time clock chips exist, and there is also a very good reason that electronic interfaces almost always have more than a single bit for input and output. But read-on if you must...
This is a fully functional timepiece, complete with Westminster quarter hour chimes (during the daylight hours only), active calibration, and a reasonably functional time-setting mechanism (considering there is only a single pushbutton and piezo present for I/O), using only a PICAXE, push-button, and speaker.