Egg Timer Dreams

Egg timer concept. Not so elegant but it’s a beginning.[/caption]

I was thinking it would be fun to make an egg timer or kitchen timer as a fun design challenge.

Egg Timer Design

There are a couple of pretty common designs but I wonder if there’s something better that could be fun and educational to make.

Seems there are two kinds. The rotary dial type and the button type. I was thinking of starting with a button type thinking it might be easy. The dial is the easiest to use and has implied state visualization. But it hasn’t dawned on my how this could be easily made.

I figure it needs magnets to hold it to a fridge. I suppose some holes for other types of hanging as well. Perhaps it should be able to sit on a counter easily but if it’s near the stove then it might need cleaning and that’s no fun.

Also I was thinking it might only need one button. Perhaps one touch is a minute and a longer touch is ten minutes. So to set it to 23 minutes is two long touches and three short touches. It could be cleared with a longer touch.

Perhaps there’s a way of doing it without contact? I want to think about that.

I figure it also needs some sort of display. Catch is those LED segments might draw a bit of power so perhaps an LCD. But I noticed  the LCDs are a bit more expensive.

Egg Timer Electronics

I’m no pro here but here are some parts I’m exploring.

3 or 4 – 7 Segment LED (tutorial, tutorial2)
3 or 4 – SN74HC595N Shift register (perhaps one of those 4 digit LED displays and one or two shift registers)
ATTINY85-20PU chips
A bright LED
A piezo Speaker
A button

Here’s a capacitive touch sensor demo (link1, link2, link3 link4)

to “Egg Timer Dreams