build your own programmable led matrix - programmable scrolling led sign

Two-dimensional code is addictive.
Smartphones are smart enough to read them from almost any angle or direction.
But imagine going further.
I dream of having a digital LED array that I can program with a QR code and I hope it's really big!
I created the QR code here with 16 matrices.
You can purchase the kit from Jameco to build the 8x8 panel.
The Led is not included, giving you the freedom to choose your own size and color.
Tools and components required: soldering iron and welding led Control library LEDs (
Recommended 10mm)
Wire cutting machine and wire stripping machine jumper cable matrix kit includes: LED matrix PCB 47 Ω resistor 10 μF capacitor control board PCB 150 k Ω resistor 0.
1 μF capacitor IRF9Z34N transistor IC socket head screw, 4-
40x3/8 "L 2n222222a transistor 2x8 head hex gasket, 4-
40x7/16 "L 1 k Ω resistor 2x8 male head hex bracket, 4/40x3/8" 1.
5 k Ω resistor max719ic installs the male head and the female head loosely together, puts the female head on the U1 of the control board, and puts the matrix board on it so that the male head passes through u1
The screen should be positive.
Both boards are OK.
Temporarily install several gaskets on the control board and place the board pair on one side so that the two boards are square to each other.
Tighten the gasket.
There is an additional benefit if you are building multiple matrices.
They will sit next to each other.
Weld them according to the values of all resistors on the control board and the screen printing position. R1 -R8 = 1k Ω (brown-black-red)R9 -R16 = 47 Ω (yellow-violet-black)R17 -R24 = 1. 5k Ω (brown-green-red)R25 = 150k Ω (brown-green-yellow)
Install the capacitor and pay attention to the marking on the screen printing.
The polarized capacitor must be positioned correctly, otherwise it will not work.
C1 = 10 μF electrolytic capacitor, polarization.
Please pay attention to the stripes indicating the opposite side.
A positive "" sign is displayed on the screen.
Welding the capacitor with enough space, you can bend the capacitor to flush with the circuit board.
Match the tab on the side of the transistor with the screen printed tab.
There are three clues that should also match the direction. Q9 -Q16 = 2N2222A.
Make sure you have 2n222222a for each transistor. (
If it's something else, it can cause the opposite action to happen once programmed.
Useful tip: Weld one lead for each transistor at a time.
So you can make some minor adjustments.
It also allows the transistor to cool briefly before soldering the next lead. Q1 -Q8 = IRF9Z34N.
These transistors must be placed in the right direction.
The silver color of the rectangle on the screen print indicates the back of the transistor.
Bend the lead back 90 degrees so that the transistor will be flat on the PCB when installed.
You can also choose to leave a little gap between the back of the transistor and the PCB so that the airflow keeps the assembly cool.
Please note the cut on the PCB and the cut on one side of the socket.
Match these gaps before welding all pins.
When installing max719ic, you should also pay attention to the gap at the end near pin 1.
You may need to get the PIN right and have it sit on the socket.
Install one line of LEDs at a time.
Weld one leg of each LED at a time, so you can make minor adjustments to their position. Take your time.
The straighter the line, the better your monitor will look.
The flat face of the LED on the display is displayed as negative.
The short leg of the LED is negative.
The standoff has passed through the ends of men and women, while the spacers are only female threads.
Spacers are located between the control board and the matrix board, while spacers pass through the spacers from the lower side of the control board.
Align the pins of the head from the mounting holes of both boards and PCB and press them together.
Fix the two modules together using the disc head screw.
It may be helpful to put the two boards on a flat side so that when they are square to each other, they may tighten.
The welding test results in a pad on the lower side of the control board, preferably with a plug pin at one end connected to the Arduino.
I connect my matrix to Arduino Uno, so you may need to replace the pins if you have different models.
Weld the jumper to the pad on the back of the control board.
Pad DataIn (DIN), Load, Clock (CLK), 5V (V+), and Ground (GND).
Copy the sample code on the description PDF of the kit to test the LEDs. (
Also found at the end of this document. )
Connect the jumper from the control board to the following pins. DIN = DataIn (
Pin 12 on Arduino)
DOUT = DataOut (
If applicable, DIN connected to the next module)CLK = Clock (
Pin 11 on Arduino)LOAD = Load (
Pin 10 on Arduino)
V = 5 v pin, connect the Arduino to VIN if its power supply is greater than 5 v, or if its input power supply is 5 v.
Daisy-is required if you are connecting other panels-
Chain them as follows.
DOUT from the first control board (
The one connected to Arduino)
Din clk connected to the next control panel the CLK connected to the next board load the load connected to the next board V can be connected together, but it is highly recommended to supply V to each board independently, to limit the flow of electricity flowing through the board GND, it can also be connected together, but in order to achieve the best operation, it is best to run a separate ground wire on each board.
Programming the LED panel can take a lot of time to determine which LEDs you want to turn on or off.
You need to install the LEDcontrol library into the library folder of the Arduino.
The library can be found here: more information about the Arduino LED control library can be found here: when you go into a series of panels for programming, writing some functions to an Excel spreadsheet to automate some programming can be easier, as the only thing that changes is the led that the panel is addressed and turned on or off.
My spreadsheet tool is designed for 16 LED matrix panels and is linked together in two groups of 8.
Spreadsheet tools (
Excel files near the bottom of the page)
Assuming there are 16 4x4 arranged panels, the order the Arduino sees is left to right from top to bottom.
Just place an "X" or other character in the cell you want to light up, and then click the "build code" button, which will create the code for the Arduino and copy it to the clipboard. (
Note: it may be necessary to lower the macro security settings in Excel to allow the button to run its function of creating code. )
I found that the best way to do the QR code is to create one on another site, import the image and zoom correctly so that each point has its own cell.
With the picture tool, you can select the white cell as the "transparent color" so you can see the cell grid behind it.
Use the keyboard to navigate between cells, because the mouse only needs to click the image.
Place a "X" anywhere, you can see the cell and leave the black cell empty (OFF)
You have it.
A sample code for an 8x8 LED matrix/the code below will open each point of the matrix to test if all LEDs work.
Including "LED control ".
Include binary files.
These pin numbers are for * LED control with Uno boot loader (name)=LedControl(
Number of DataIn, CLK, LOAD, max72 19)
* Pin 12 data input connected to the first cluster of 8 * Pin 11 connect to CLK * pin 10 connect to load * 1-
8 */LED control lc0 = led Control (12,11,10,1); void setup(){
/When creating the LED control int device ea = lc0, we have set the number of devices. getDeviceCount();
/We must be in the loop (int addressA=0;