Diy Led Matrix

WhatsApp Image 2026-05-02 at 6.10.19 PM (4).jpeg

I made this because i wanted a way to display animations and scrolling text using leds.

Supplies

Tools

3d printer - click here
soldering iron - click here
glue gun - click here
plyers - click here
wire strippers - click here

Components

led - click here
resisters - click here
raspberry pi - click here
button - click here
light sensor - click here
sound sensor - click here
jumper wires - click here
electrical tape- click here
any colour fillerment- click here

Testing the Leds

First ~II tested everything on a breadboard to make sure all of the components worked. to test them i used a 220 ohm resistor connected to a my power supply on 5 volts.

3d Printing a Jig

You then need to 3D print a jig which would allow you to solder 25 LEDs into a 5 by 5 square. The 3d files are linked down below here. You can 3D print them in any 2 colours you like; 1 for the colour for the writing and one colour for the main body.

Downloads

led jig (final).stl

Soldering the Leds

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Next, you need to solder the LED's together. To do this, you need to have all the short legs touching each other and facing right. This will be row 1. The long legs are going to face down and they will be columns. Once you have done one row repeat the step for 5 rows and columns.

Soldering Resitors and Hookup Wire

Next you need to solder 5 220 ohm resitors to each row of the matrix because you dont want the leds to burn out. after you have soldered the resitors cut 5 femail jumper wires in half and strip the ends of the wire. once you have done that solder them to to each 10 legs of the led matrix.

Insulating the Wires

Next you should put some heatshrink or electrical tape around the resitors and hookup wire. you need this to stop the wires touching each other. if you did not do this step your leds could short circuit.

Testing Your Led Matrix With a Rasberry Pi

You first need to connect all of the jumper wires from the matrix onto the rasberry pi to be able to connect the code i have made a wiring diagram below

Connection Type	Pin 1	Pin 2	Pin 3	Pin 4	Pin 5
Columns (Cathode)	Col 1 GPIO 12	Col 2 GPIO 16	Col 3 GPIO 20	Col 4 GPIO 21	Col 5 GPIO 25
Rows (Anode)	Row 1 GPIO 5	Row 2 GPIO 6	Row 3 GPIO 13	Row 4 GPIO 19	Row 5 GPIO 26

Testing the Led Matrix

Now you have connected the matrix to the pi you now need to programme it. Copy the code below into thoney and click run you should have a smiley face displayed on the leds.

import RPi.GPIO as GPIO

import time

GPIO.setmode(GPIO.BCM)

# ----- PIN SETUP -----

rows = [5, 6, 13, 19, 26]

cols = [12, 16, 20, 21, 25]

button_pin = 17

ldr_pin = 27 # simple digital light sensor

for r in rows:

GPIO.setup(r, GPIO.OUT)

GPIO.output(r, 0)

for c in cols:

GPIO.setup(c, GPIO.OUT)

GPIO.output(c, 1)

GPIO.setup(button_pin, GPIO.IN, pull_up_down=GPIO.PUD_UP)

GPIO.setup(ldr_pin, GPIO.IN)

# ----- BRIGHTNESS -----

def get_delay():

if GPIO.input(ldr_pin) == 0:

return 0.002 # bright room

else:

return 0.006 # dark room

# ----- DISPLAY FUNCTION -----

def display(pattern, duration=0.5):

end_time = time.time() + duration

while time.time() < end_time:

delay = get_delay()

for r in range(5):

GPIO.output(rows[r], 1)

for c in range(5):

GPIO.output(cols[c], not pattern[r][c])

time.sleep(delay)

GPIO.output(rows[r], 0)

# ----- PATTERNS -----

heart1 = [

[0,1,0,1,0],

[1,1,1,1,1],

[0,1,1,1,0],

[0,0,1,0,0],

]

heart2 = [

[0,0,0,0,0],

[0,1,0,1,0],

[0,1,1,1,0],

[0,0,1,0,0],

[0,0,0,0,0],

]

smiley = [

[0,1,0,1,0],

[0,0,0,0,0],

[1,0,0,0,1],

[0,1,1,1,0],

]

# Simple font for scrolling text

letters = {

"H": [

[1,0,1],

[1,1,1],

[1,0,1],

],

"E": [

[1,1,1],

[1,0,0],

[1,1,0],

[1,0,0],

[1,1,1],

],

"L": [

[1,0,0],

[1,1,1],

],

"O": [

[1,1,1],

[1,0,1],

[1,1,1],

]

}

def scroll_text(text):

columns = []

for char in text:

if char in letters:

for col in zip(*letters[char]):

columns.append(list(col))

columns.append([0,0,0,0,0])

for i in range(len(columns) - 4):

frame = []

for r in range(5):

row = []

for c in range(5):

row.append(columns[i+c][r])

frame.append(row)

display(frame, 0.1)

# ----- MODES -----

mode = 0

last_button = 1

try:

while True:

button = GPIO.input(button_pin)

if button == 0 and last_button == 1:

mode = (mode + 1) % 3

time.sleep(0.3)

last_button = button

if mode == 0:

display(heart1, 0.3)

display(heart2, 0.3)

elif mode == 1:

display(smiley, 1)

elif mode == 2:

scroll_text("HELLO")

finally:

GPIO.cleanup()`

Downloads

smily face code.py

3d Printing a Case

once you know everything works and everything is strong you need to 3d print a case for your matrix. This case includes a hole for a light sensor a button and a nice back.

Downloads

Led matrix case (full).stl

Assembling the Case

firstly, you will need to cut 2 female jumper wires in half and solder them to a light sensor and a button.

secondary once you have soldered wires to the component's the button needs to go in the button enclosure and be clicked onto the case.

thirdly you need to feed the light sensor through the holes on the case.

finaly, you need to slot the led matrix into the holes on the case it should be a perfect fit.

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I Built a Smart LED Matrix with a Raspberry Pi | Scrolling Text | Animations | 3D Printed Case

Once you have done that you will have a fully working led matrix if you want to have a smart dashboard with live contols i will go over that in another instructable tutorial. I hope you have enjoyed making the led matrix i certainly have enjoyed making it.

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