15x7 led matrix

Hi all, i'm new to the forum so sorry if i'm doing something wrong.
So, i have to build a 15 x 7 led matrix for building a "mini" stacker arcade , the leds are all blue 5mm(105 total LEDs).
I'm new to the arduino world so I don't really know how to wire them and what else is needed, can someone help me ?

Hello, you are going to need led driver chip(s). The best chips for this are max7219 and ht16k33.

With max7219 you will need to split your matrix into two halves (electrically speaking) and use a max chip for each half.

With the ht16k33 you may be able to keep your matrix as a single array, as long as you have 7 cathodes and 15 anodes.


Hi paul , thank you for the help, may I ask you some question ?
The chip is for controlling the matrix ?
Can arduino supply energy for all 105 LED's ?
Where do I attach the chip ?
Do you have any schismatic similar to my project ?
Thank you againg and sorry for my ignorance.

Yes, the chip(s) control the matrix.
Yes the Arduino may be able to supply some "energy" to all the leds. You need to understand the difference between energy and power.
The level of power that the Arduino can supply to the matrix depends on which type of Arduino you have.
You attach the chip(s) between the Arduino and the matrix.
Because i do not have a schematic for your project, i do not know of a similar schematic. Can you give the schematic for your project?

I don't really have a schematic for my project but I was planning to wire the led in series and then to attach them to the chip like some 8x16 led matrix that I found on the web.
My doubt is that if I don't use an external power supply the LEDs will not be brighter enough ??

You need to control the LEDs individually?
With MAX7219, only 8 are actually on at a time, 800 Hz multiplexing and persistence of vision lets see all being on at once.
With two MAX7219, that would be up to 16 on at once. Arduino may or may not be able to drive them all - that depends on the Rset current limit resistor you use and the brightness setting (15 levels) selected.
At 20mA, 16 LEDs, that's 320mA. Feeding Arduino with 7.5V into the barrel jack would be fine, 9V may cause the 5V regulator into thermal shutdown, 12V will for sure.

Schematic - connect up 8x7 to one matrix, and 7x7 to the other. Here's the start of a matrix showing anode and cathode connections.

If you just want them all on at once, then you can wire them in series, how many depends on the power supply you are using, how many volts it is, and the Vf of your LEDs.
How many volts across an LED when it is turned on - connect a 1K resistor to +5, then to an anode, and cathode to Gnd. What is the voltage measurement at the anode? 3.2V? 3.5V? That is your Vf.
(5V - 3.2V)/1000 ohm = 1.8mA
Try a lower resistor for brighter:
(5V - 3.2V)/10mA = 180 ohm Bright enough yet? etc.

Hi, so if I wire them like in this schematic multiplied x 2 I will be able to turn on like 30 leds at the same time ?
Because the game need so.

I need also to have a button to control the game, where do I connect it ? To the chip or to arduino ?

We cannot view your schematic.

Please answer the question. Do you need individual control of these leds? Your original post referenced a game where each led was individually controlled. But your posts since then have been confusing. Will there be 105 leds or 30 leds?

Your button will connect to the Arduino, between a digital pin and ground.

Yes, you can send data to the MAX7219s and make as many LEDs turn on together as you want.
Button, that connects to the Arduino.

Hi, sorry for the confusion.
I need to build a 15x7 matrix so a total of 105 LEDs and I need to control them individually so I can replicate the stacker arcade game.
I'm planning to follow this schematic https://cfpmanfredini.files.wordpress.com/2013/03/7219_64led_ckt.png but doubled.

In the other post I asked if with the max7219 I will have enough power to turn on 30 of the 105 LEDs at the same time.

I'm planning to follow this schematic but doubled.

Yes, if you can follow what that diagram means. You need to "chain" the two modules with the Data out of one MAX7219 (not shown on that diagram) connected to data in of the other.

You also need to include a 0.1 µF capacitor directly across the supply terminals of each MAX7219 and at least a 22 µF capacitor across the supply of the pair.

In the other post I asked if with the max7219 I will have enough power to turn on 30 of the 105 LEDs at the same time.

Of course it is not whether the MAX7219 "has enough power"; it is whether the Arduino can supply it. If you are using the USB connection to provide power it will be OK, but not the regulator from the "barrel jack" or Vin. You need a fully regulated supply of 5 V for the MAX7219s and given that it is regulated, you can supply the Arduino with it as well on the 5 V terminal. That is of course, exactly what the USB connection does.