ATMEGA328P 7 segment generic display

Two lines of 4 digits 7 segment display using ATMEGA328P chip (Arduino UNO) can be used as clock with external RTC or as general display.

Similar projects worth following
I want to create 7 segment display that can be used for different purposes. For example as timer, clock or voltage/current display for DIY PSU. So LDS-3492AX (exactly like YSD-439AR6B-35 from SparkFun) 4 digits 7 segment display was chosen because it has colon and apostrophe, so clock and temperature can be nicely displayed.

Of cause I am aware of 7 segment display controller ICs like MAX7219. But it is no easy way to use such IC for display with colon and apostrophe, especial if you want brightness control and same brightness for colon and apostrophe as for digits. So I choose to use Atmega328p chip. This will allow to use this display as slave writing digit values via I2C or standalone as clock, with temperature sensor or anything else.

So what you see here is Schematic and PCB and example Arduino sketch of clock implementation with external RTC module. There are also Gerber files for Seeedstudio Fusion PCB service so you can easily produce PCB only for 5$ (not including shipping)

Generally PCB can be used with common anode 7 segment display as well as with common cathode 7 segment display. You only will need to use right type of transistors and connect J5 jumper accordingly.

I did mistake with buttons location. Actually I wanted them at the bottom. Anyway I will do additional version of PCB with buttons located at the right side of 7 segment displays.

I am not providing explanations other then schematic and example of code currently because I don't sure if anyone will be interested. But I will add explanation on request.

Eagle files V1.1

x-zip-compressed - 568.72 kB - 01/20/2018 at 13:41


Arduino sketch V1.1

x-zip-compressed - 786.88 kB - 01/20/2018 at 13:39


Arduino sketch

x-zip-compressed - 5.76 kB - 05/02/2017 at 14:37


Eagle files

x-zip-compressed - 512.44 kB - 05/02/2017 at 14:36


  • 2 × LDS-3492AS 4 digit 7 segment display
  • 1 × SN74HC595N Shift Register
  • 1 × 16 MHz Crystal
  • 1 × ATmega328P Microprocessors, Microcontrollers, DSPs / ARM, RISC-Based Microcontrollers
  • 8 × 2N2222 Discrete Semiconductors / Transistors, MOSFETs, FETs, IGBTs

View all 3 project logs

Enjoy this project?



Similar Projects

Does this project spark your interest?

Become a member to follow this project and never miss any updates