Instructables

7 Bi-color LED Matrix Scrolling Text Display

Picture of 7 Bi-color LED Matrix Scrolling Text Display

Here, we show how a 7 Bi-color 8x8 LED Matrix Scrolling Text Display is built, in which messages and commands can be sent to it via Bluetooth using an Android Smart Phone. Logically, any devices capable of sending text messages via Bluetooth may be adapted to work with the display.

To build this project, basic electronics component soldering skills and some knowledge on using the Arduino or Arduino based micro-controllers are required.

The reason for building a 7 LED Matrices long display is that it is quite adequate for ease of reading scrolling text and also because the largest tinted acrylic sheet easily available in Hobby or Art shops is 18 inches by 12 inches, which is just the right length for making the enclosure for the display as each LED matrix is around 60mm x 60mm in size.

You may view the following YouTube video to see what we are building.

 
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Step 1: LED Matrix Driver Module Assembly

Picture of LED Matrix Driver Module Assembly

The display is built using seven of the Bi-color (Red and Green) LED Matrix Driver Module kits from jolliFactory. Each of these modules uses two MAX7219 Display Driver ICs to drive a Bi-color LED Matrix. These ICs are excellent because they take a lot of work off the micro-controller and simplify the wiring and logic design. Moreover, there is a ready-made Arduino library for this IC. You can daisy-chain up to four of these Bi-color LED Matrices using only three output pins on the micro-controller for the interface. As our display is made up of seven Bi-color LED Matrices, we need an additional three output pins on the micro-controller to interface with the other three daisy-chained LED Matrices.

You can find this Bi-color LED Matrix Driver Module kit from here with information on the assembly of the kit.

This kit comes with all through-hole components and someone with basic soldering skills should be able to assemble it without much difficulty.

You may view the following YouTube video on the assembly of the Bi-color LED Matrix Driver Module kit.


The following are some of the projects built using this Bi-color LED Matrix Driver module which you may want to check out:

profort10 months ago
How much did this wonderful build cost to make?
jollifactory (author)  profort10 months ago
The chipKit UNO32 micro-controller currently cost around U$32, the HC-07 Bluetooth Wireless Serial Port Module around U$10 and the 7 pieces of the Bi-color LED Matrix Driver Modules cost U$12.50 each. Here, 7 Bi-color LED Matrix Driver Modules are chained together to form a long display. However, you may use lesser number of modules to form a shorter display.

You may like to check out the Bi-color LED Matrix Driver Modules at https://www.tindie.com/products/Nick64/60mm-x-60mm-bi-color-led-matrix-driver-module-diy-kit/
jollifactory (author)  jollifactory6 months ago

For those interested, the Bi-color LED Matrix Driver Module now cost U$10.50 if four or more is ordered at
https://www.tindie.com/products/Nick64/60mm-x-60mm-bi-color-led-matrix-driver-module-diy-kit/

bilko11 month ago

Hi

Can I ask a question is it possible to have the text scrolling north to south and mount the sign vertical as well as right to left and horizontal as shown in the video

Cheers bill ,

jollifactory (author)  bilko11 month ago

It should be possible but you need to modify the project's Arduino sketch.

Very interesting. Let me once try this instructable on next week.

There is also a circuit named Bipolar LED Driver which is built using microcontroller and is very interesting. If anybody interested, also visit that page.

bukkyforreal3 months ago

pls how can i get

chipKit UNO32 micro-controller

jollifactory (author)  bukkyforreal3 months ago

You may find it at

http://www.farnell.com

thanks.but Nigeria is not part of the listed region .pls, can u help me with the circuit diagram and source code for

UNO32 micro-controller

minipada6 months ago

Any solution for a long-life battery ?

jollifactory (author)  minipada6 months ago

Not sure if I get you right. I have powered the 7 LED Matrix display using four AA batteries with success but did not explore using longer life batteries.

I searched for a long life battery which can handle the LED matrix display.

Is it posible to make this work with an rgb strip display? And if it is how can i do it and thanks for your answer
jollifactory (author)  arodriguez castro8 months ago
Sorry. It is not possible to drive rgb strip displays.
TheLarryCover9 months ago
What is the maximum number of led matrix driver you can chain? Limitation will come from available digital ports and may be power no?
jollifactory (author)  TheLarryCover9 months ago
You will need to modify the program code found in this instructables if you intend to drive more than 8 bi-color LED matrices. if I am not wrong, with the chipKit UNO32 micro-controller I am using here, using the available digital ports alone should be able to drive up to16 bi-color LED matrices. The available analog pins can also be used identically to the digital pins and should allow you to drive another additional 8 bi-color LED matrices. However, the display scroll speed will be much slower with more LED matrices chained together.