Toothbrush timer (Arduino Nano + OLED display SSD1306)

Timer to help your kids brush their teeth properly. 2 minutes in total. Shows which part of the mouth to focus on and displays a smiley face when finished.

Hardware required

• Arduino Nano (or its clone, works both on ATmega168 and ATmega328)
• SSD1306 0,96'' OLED display
• 2x 10kΩ resistor (when using ATmega168)
• 9V battery connector + 9V battery
• mini toggle switch (on/off)
• a few wires to connect everything

Arduino source code

https://github.com/mkosiedowski/tooth-brushing-clock

Wiring

https://www.instructables.com/Monochrome-096-i2c-OLED-display-with-arduino-SSD13/

Basically, connect:

• Arduino A4 to SDA display input
• Arduino A5 to SCL display input
• Arduino GND to display GND
• Arduino 5V to VCC display input

With ATmega 168 based Arduino Nano you will most probably need a pull-up resistor on SCL & SDA inputs of your OLED screen. Just connect them to proper A4/A5 output ports of your Arduino board and also connect them through 10kΩ resistor to 5V output of your board

Connect 9V battery:

• (+) to one of the switch ports
  • connect the second port of the switch to VIN in the Arduino board
• (-) to GND in the Arduino board

Print instructions

Prints well with PLA, 0.2mm layer. Use supports (you can add it everywhere, it's easy to remove them after printing).

Assembly

• 9V battery goes to the right side of the case
• Arduino nano goes to the left side of the case
• switch goes to the back of the case
• Display slides into the socket in front
• Lid snaps into the latch on top
• Ready!

Demo