Simpleclock is a easy to assemble attractive 4-digit 7-segment LED display clock with temperature and alarm function. It is available in three colors: Red, Blue and White.

It comes as a kit of through-the-hole parts and can be soldered by any person with basic soldering experience. An attractive acrylic stand is included.

The firmware is open source, and is written in the Arduino IDE allowing anyone to modify and program the clock easily (for programming, an FTDI adapter is required. If you don’t have one, you can buy it from our shop along with simpleclock.)

The clock is a modular design, and comes on two PCBs. The back PCB is an ATMega328P-based microcontroller board (with Arduino bootloader installed), and comes with all the components required to run your clock (DS1307 real time clock chip with battery backup, DS18B20 temperature sensor, piezo and control buttons and switch).

The front PCB, where the display is mounted is our popular

null. This arrangement not only makes the firmware easier to understand (by delegating the tedious task of multiplexing the display to the TWIDisplay's onboard processor), but as an added bonus, the backpack can be detached and the TWIDisplay with stand can easily be attached to another microcontroller to use with your own project.

The clock is powered by a 5V USB mini-b cable, either directly from your computer or from a 5V regulated USB power supply (cable and power adapter not included).


  • Clock and alarm
  • Thermometer
  • Simple to use menu system (same interface as the null)
  • Open source firmware written in Arduino
  • Arduino bootloader and serial pin header for easy re-programming using an FTDI adapter
  • Comes with detachable TWIDisplay: Use either with the clock backpack or connect another Arduino or microcontroller with TWI/I2C support to re-use the display for your own project.