How to interface Arduino with SZ2107889 dot matrix board

How to interface Arduino UNO with dot matrix display

LED dot matrix boards are very popular means of displaying information in the form of static, animated images and text.  Here let’s learn how to interface a dot matrix board with arduino UNO. The main aim is to display a character on the dot matrix board using the arduino and shift register IC.

Components required

• Arduino UNO board.
• Dot matrix board.
• 74595 shift register IC.
• Resistor 100 ohm -8 no.
• Connector wires: 20 no.

Component description

• Dot matrix board

Multiple LEDs are wired together in rows and columns.  Here we are using an 8x8 dot matrix board.  It will be having 8 rows and 8 columns. The rows are named as R1-R8. Columns are named as C1-C8.  Here all the anodes are wired together in rows and all the cathodes in columns. Each LED in the matrix board is addressed by the row and column number.

Structure of 8x8 LED dot matrix

Suppose we want to display the character A. So we have to select column C1 and deselect other columns. C1 is selected by making it to LOGIC 0 and C2-C8 is deselected by making it to LOGIC HIGH. Now C1 is active. The next step is to make the rows R2-R7 active. This is done by giving forward bias voltages to the rows. This process is repeated for rest of the columns and rows. By scanning the columns and making the LEDs ON; the image A will be displayed.

The table below shows how to select and deselect the rows and columns to display the character A.

  HEX          0x00          0xFE         0x11       0x11         0x11         0x11        0xFE        0x00        

Note: The hex values are written in the order as indicated by the arrow. These hex values are used in the program for displaying the character ‘A’.

• 74HC595N Shift register

Shift register IC, 74HC595N converts serial data to parallel data. The IC is used here to minimize the use of digital pins of arduino for controlling the display board.

Pinout and functions

Program

In the program we will be displaying the characters. The program is attached as PDF below...