Standard Parts

Below is a list of all the standard parts required to build an overhead alarm clock, along with the sources of supply*.

Special parts such as front panels, mounting plate and pcb as well as small parts (screws, nuts etc.) can be found on the page Special- & Small Parts.

* the parts and shops of this list are of course only suggestions; if you know better or cheaper: Infos welcome!

  • Wooden box, 1 piece, as housing, MidaCreativ
  • Red display, 1 piece, time display, EXP Tech
  • Yellow display, 1 piece, indication of alarm time, EXP Tech
  • Connection cable with socket and plug, 5-pin, 2 pieces, connection of the displays with the pcb, Marotronics
  • Adafruit DS3231 Precision RTC Breakout, 1 piece, keeps the exact time independent of the Arduino, EXP Tech
  • CR1220 3V Lithium button cell, 1 piece, keeps the clock running, even with interrupted 5V supply, EXP Tech
  • MP3 player module, 1 piece, plays the alarm sound, Amazon
  • SD card, 1 piece, contains the MP3 file which serves as alarm sound, Pollin
  • Adafruit FRAM Breakout, 1 piece, saves the alarm time, even with interrupted 5V supply, EXP Tech
  • Button red, 4 pieces, for setting the time, EXP Tech
  • Button yellow, 4 pieces, for setting the alarm time, EXP Tech
  • Rotary switch, 2 pieces, for the operating modes "Clock: Run/Set" and "Alarm: Off/On/Set", Pollin
  • Rotary potentiometer, 3 pieces, two for brightness and one for volume, Pollin
  • Connection cable with socket and plug, 2-pin, 9 pieces, eight for the push buttons and one for the clock switch, Marotronics
  • Connecting cable with socket and plug, 3-pin, 4 pieces, three for the potentiometers and one for the alarm switch, Marotronics
  • Rotary knob red, 2 pieces, one for the clock potentiometer, the other for the clock switch, Pollin
  • Yellow rotary knob, 3 pieces, 1x alarm potentiometer, 1x alarm switch, 1x volume switch, Pollin
  • Built-in loudspeaker, 1 piece, alarm sound output, Amazon
  • 1k resistor, 1 piece, for use in the circuit board, Pollin
  • 10k resistor, 11 pieces, for use in the circuit board, Pollin
  • Stacking strip 40-pin, 2 pieces (subdivide into 1x 18-pin, 1x 10-pin, 3x 8-pin), Marotronics
  • Stackable Header - 8-pin (pack of 10, only 4 pieces needed), 4 pieces, for RTC-, FRAM- and MP3-Module, EXP Tech
  • Configurable Spring Terminal Blocks, 5 pieces, to connect the PCB with relay PCB and loudspeaker, EXP Tech
  • MEGA 2560 R3 ATMEGA Board Arduino Mega 2560 comp., 1 piece, for operation of hardware and software, Eckstein
  • Relay, 1 piece, to separate the loudspeaker input as long as no MP3 file is played (avoids disturbing noises such as humming), Marotronics
  • USB cable 1.8m, 1 piece, to connect the Arduino with the Power Bank, EXP Tech
  • Power Bank, 1 piece, for power supply of the Arduino, also in case of power failure, Amazon
  • Switching power supply, 1 piece, for power supply of the Power Bank, Pollin


Further Material

  • Some jumper wire
  • Heat-shrink tubing
  • Dowels + screws for wall mounting
  • Optional: Cable duct plus dowels and screws for laying the USB cable (between alarm clock and Power Bank)