Avian’s Blog

I've made a simple day-of-week display today. I hope it will help my grandmother and grandfather remember which day it is so they can take the correct medications.

It seems that complexity of scheduling various pills rises exponentially with age and I was surprised that I could find no electronic aides on the market that would help old people with that. It's simple to write the schedule on paper but you still need some kind of automatic calendar that doesn't depend on the user to advance the "today" indicator. I couldn't even find a clock that would display the day of the week in Slovene (not to mention in big readable letters).

So I made my own. Time was important so I made this as simple as possible (it took me a day and a half to put everything together): I used an old stopwatch and connected a simple detector circuit to it instead of the buzzer. The detector gives a clock impulse to a 7-state Johnson counter each time the alarm would sound which in turn advances the display for one day.

I power the clock from a 1.5V battery which removes the need for 12V to 1.5V DC-DC conversion and adds the benefit that the clock continues to run even if someone unplugs the device.

Looking at it now it reminds me of those scenes in Hollywood movies where they argue if someone should cut the red or the blue wire.