Introduction: How to Interface 8*8 7219 Dot Matrix Led Display With Arduino

Picture of How to Interface 8*8 7219 Dot Matrix Led Display With Arduino

Hello guys, here we are with one more basic tutorial and that is how to interface 8*8 dot matrix led display with arduino.

Step 1: All About 8*8 Dot Matrix Led Display

First of all let me tell you about max7219 IC and how it is connected to total 64 led which is there in our 8*8 dot matrix.Usinga 7219 IC you can drive 64 LEDs while you only need 4 wires to interface it to a microcontroller. In addition you can daisy chain multiple(up to 8) 7219 chips for bigger displays. There are 16 output lines from the 7219 driving 64 individual LEDs. This sounds impossible but the driving method makes use of the way our eyes work. Persistence of vision is exploited to make the LEDs appear to be on all the time when in fact they are not. In fact the LEDs are arranged as an 8x8 set of rows and columns. Each column is pulsed for a short time while the row bits for that column are driven. As our eyes remember a flash of light for approximately 20ms, so when you continuously flash a light (or an LED) at a rate at or faster than 20ms, then it appears that the light never goes off. This is how the 7219 works. All the leds are individually turned on for a short time, at rate greater than 20ms.

Step 2: Max7219 SPI Interface

The MAX7219 has a four wire SPI interface - clock, data, chip select and
ground - making it very simple to connect to a microcontroller.

Data - MOSI - Master Output Serial Input. The 7219 is a slave device.

Chip select - Load (CSn) - active low Chip select.

Clock - SCK

Ground.

Step 3: Circuit Diagram

Picture of Circuit Diagram

As you can see our arduino is connected to dot matrix display through 7219 ic. Here only 5 wires are needed to connect this dot matrix display to arduino uno.

Step 4: How to Program This Display

to run this display is very simple. As we have many already built in libraries are there for this device. So here we are using LEDControlMS library. For more information about this library you can visit this link.

Using this library you can control upto 8 dot matrix display by connecting all display in a daisy chain manner.

now from below you can just download that library and just add this library to your arduino IDE.

Adding library is very simple

First download that library and now unzip that, after unzipping you just paste that library in a library directory of your arduino IDE.

So now just restart your arduino IDE. Now if you will go to Files-> Examples->LEDControlMS

Here you can find some demo codes.

Now in our case we have uploaded and tested the code named MakeSpace_LEDMatrix


Step 5: Conclusion

If you have any doubt regarding this project feel free to comment us below or you can mail us on info@deligence.com And if you want to learn more about these type of project then feel free to visit our youtube channel

Thanks & Regards,

Deligence Technologies

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Bio: We are a team of IoT & Embedded Systems developers. We are working in Raspberry Pi and Arduino.
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