Easy 4x6 LED Matrix, Arduino!

 

In this inst'able, I will show you how to create your very own 4x6
LED matrix as well as show you how to write code for it!

There is an animation creator program in step 4!

Here is one ANIMATION to get you excited about the project!

***Wave Animation***

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Hello everyone! I'm back with an all new Inst'able!

This Inst'able is for the electronic enthusiast/hobbyists that has basic
knowledge of the simple hardware used, and a good grasp of the
arduino programming language!

Email me at "[e-mail]" if you have any questions about
the instructable.
Post Videos of your own LED Matrices!

FOLLOW ME FOR MORE GREAT INSTRUCTABLES!!

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Step 1 Hardware

For this project you will need:

• An arduino board;
• Twenty-four LEDs of the same color;
• Four transistors;
• Four 100ohm resistors;
• Four 1Kohm resistors;
• And a fair amount of wire.

"C" stands for Column while "R" stands for Row.
Columns are vertical, varying the Y axis
Rows are horizontal, varying the X axis.

Click Here for a bigger and better res. view of the above schematic

How The Hardware Works:
        The hardware works by applying +5 volts to the desired column and row, and having GND wired to the arduino's GND pin. If I apply +5v only to C1, there will be +5v ready to be passed through all of the LEDs in column 1, but still has to go through the transistors in order to get to GND and there are no LEDs on.. On the other hand, if I apply +5v only to R1, that transistor will allow current to pass from any LED in row 1 to GND. But since there is no voltage applied to any of the columns, no LED is turned on.
        From what I have said thus far, we can see that +5v must be applied to a Column and a Row at the same time for any LED to be turned on. Here is where we run into a problem: the only way to turn on 3 LEDs [(C1, R2), (C1, R1), and (C2, R1,) which are the three lowest and to the left] is to apply +5v to pins R2, R1, C1, and C2. The problem with this is that it will also turn on LED (C2, R2)! See step 2 for how to solve this problem, read on for the technical specs!

Technical stuff...
Schematic Pin Name-----------Digital Arduino Pin They Connect To
C1......................................9
C2......................................8
C3......................................7
C4......................................6
C5......................................5
C6......................................4

R1......................................10
R2......................................11
R3......................................12
R4......................................13

GND...................................GDN     Well, duh!     = )
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Comments

[Grumpy Mike]

While the circuit / age ratio might be admirable it is a poor use of transistors. Basically the 100R resistor should not be in the emitter but in the collector. As you have it in the emitter current flowing through it will raise the voltage on the emitter, thus reducing the voltage between the emitter and the signal driving the base and so cutting off some base current. While this might work for you it is a poor design because it might not work for other transistor or transistor types because it needs a much higher gain from the transistor than you would otherwise need. It could cause the transistor to not be fully saturated and that will increase power dissipation in the transistor.

[osarbantovi s]

Just made my 4x4 matrix, without transistors only 8 resistors(actualy 4 are used). Codes placed here works just fine after I changed pin numbers

[Acarius]

Do you have any images on what the matrix looks like without the plastic cover?

[rtty21]

no. the matrix is built around the plastic cover. just to clarify, the LEDs are on the outside of the plastic, in case you didn't know...

[robot1398]

do you have the pcb design for this

[rtty21]

i do not, sadly. I put it together on a small plastic container.

[Electronics Man]

would it be possible to use an existing LED matrix that is a 4x6 instead of making one?

[rtty21]

If you can solder wires to the anode-columns and the cathode-rows, you should--in theory--be able to use it.


If you have cathode-columns and anode-rows
instead of anode-columns and cathode-rows you will have to wire the devise differently. Interestingly enough, you would have less brightness fluctuation. This is due to the fact that instead of six LEDs sharing the same transistor and resistor, we now have only four.

[Electronics Man]

Thanks for the info it really helped

[rtty21]

no problem!

[Avadhut.Deshmukh]

good work i will start this buy arduino soon

[robot1398]

cool did you create all these codes

[rtty21]

Yup! I wrote each program.

[sanjib_cu]

hi
i am interested to design a led matrix display having dimention 4.5'' x 1.5'' .
will you suggest me how we can do it with less expenditure compair to the conventional one. Please also try to inform me what precautional measure i should take to run it for a long time continuasly -- ROSKY

[rtty21]

If you use 3mm LEDs, you will be looking at a total of 38 LEDs wide by 12 LEDs tall. thats a total of 456 LEDs!!
The first thing I would like to point out is the power consumption that this will take. A high efficiency colored LED consumes somewhere around 2 Milliamps when at normal brightness. when you take 2Milliamps x 456 LEDs, you get a total of 912 Milliamps! that is basically one amp. I don't believe an arduino should be subjected to this kind of power consumption.
Secondly, You will need to write CODE upon CODE to program this thing! with a total of 456 LEDs to control, You will likely spend 10 hours of coding for every 5 seconds of animation.
In closing, good luck! and I expect it to be done by next monday.    =D

[pfred2]

Easy for you maybe. hehe J/K! It looks pretty cool. I have a sleeve of matrix displays here and a driver IC I never did anything with. One of these days ...