8x40 LED Matrix Clock Using DS3231 RTC Module and Arduino

In this article I will show to how to make LED Matrix Clock. This clock uses DS3231 real time clock module that provide the precise time. It can display Time, Date, Day of week and Temperature. We can also update its time using Infrared TV remote.

Let's get started!

This tutorial gives you all the information that you will need to make your own led matrix clock. In further steps I will provide some additional details that would be helpful to do the project.

Components you will need to build this project:

• Arduino
• DS3231 RTC Module
• 8x40 LED Matrix (uses 74hc595 shift registers)
• IR receiver

Components for LED Matrix:

• LED Matrix PCBs x 5
• LEDs x 330 (I'm using 5mm Starw-hat White LEDs)
• 74hc595 Shift Registers x 6
• 100 or 220 ohm resistors
• Headers

Tool:

• Soldering Iron
• Wires
• Wires cutter

PCB Gerber Files and List of the components are below.

For this clock I designed 8x40 Led Matrix. This matrix consists of 5 8x8 matrices that uses 74hc595 8-bit shift registers to control the LEDs. You can build your own LED matrix on a circuit board.

Or you can buy 5pcs of PCB prototypes for only $2 (any color) from JLCPCB to make your project look more professional. If you order now using above link you will get special offer 1-4 layer PCBs with Free PCB Assembly. So, download the Gerber files and click on the link to order now!

Assemble the PCBs:

When all the components are arrived its time to assemble the PCBs. First solder the resistors and then shift registers. You should be careful while soldering the shift registers. Correctly place them on the PCB and make sure that dot on the PCB and on the shift register is on the same side. Then solder the LEDs and Headers on the PCB.

Note: On the first PCB I soldered two shift registers and on rest of them I soldered only on the right side. Because right shift register controls the columns and the left shift register controls the rows. All the rows of matrices are connected to each other using the headers. So, we don't need to add left shift register the rest of the PCBs.

When all the PCBs are assembled connect them together. And our 8x40 LED Matrix is complete.

Connect all the components to Arduino according to this Schematic.

First download the library for DS3231 rtc module and add it in the Arduino library folder, then download the code from below and open it in the Arduino IDE. In the code you will need to change the hexadecimal values of the remote and set them to your remote buttons so that we can update the time and date using remote. After that upload the code to Arduino.

We can set time using four buttons of IR remote. By pressing:

1. Mode: Enter in the Setup mode or Exit
2. Select: Select Time, Date and DOW or select any digit in Time and Date
3. Increase: Increase the value of selected digit
4. OK: Save the changes

I made this frame out of wood and painted it. And also secured the glass in its place. Then I put LED matrix and control electronics in the frame and close it.

Now, LED Matrix clock is complete. We can power this clock with any 5V power supply.

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