My kids always brush too fast.

So I make them a clock with a button on the top which when pushed will start counting from 1s to 120s.

They are now using that as their 2 minute timer.

It is a pretty simple project,

if you have an RTC clock and an Arduino compatible board you can get it done.

Step 1: Material

1 Sparkfun Redboard (or any Arduino compatible)

1 Seven Segment Display kit

1 RTC DS1307 Clock kit (see Adafruit Tutorial on how to get or build one your self)

1 push button

Some Plexiglass for overall case. I just make a box from it and glue them together. Nothing fancy.

The RTC Clock is put inside an empty dental floss container so I don't have to cover or worry about short circuiting the board inside the case.

Step 2: Setup Your Connections

Time to get your breadboard out.

I used Sparkfun tutorial here to connect the 7 segment

I am opting for the Serial UART connection.

Similarly I use this Adafruit tutorial for my RTC clock connection with i2C connection