2pcs MAX7219 Dot Matrix Module(Red Light) 4 in 1 Display for Arduino Microcontroller with 5Pin Line(Christmas Decoration DIY Letters Electronic Display)

I soldered both modules together with very short, stiff jumpers (removed plastic and bent included 90 degree pins) to make 1 long display. It works very well once I figured out how to properly configure everything. I'm adding these to my list of "known good and useful" Arduino accessories for future purchases! The only thing that could make these better is if the seller would just send them for free! :)I used a NANO, so your setup may be a little different... I couldn't find the answers easily out there in Arduino land, so I'm including what I used to get it all working with both the example Ticker sketch and my clock program in case you too are having issues.#include <SPI.h>#include <Adafruit_GFX.h>#include <MAX72xxPanel.h>and for both displays connected together I needed://constants will not change...const int pinCS = 10; // Using Arduino NANO! Attach CS to this pin(10), DIN to MOSI(11) and CLK to SCK(13)const int numberOfHorizontalDisplays = 8; // 2x 4 module panels attached togetherconst int numberOfVerticalDisplays = 1;...and in void setup() matrix.setPosition(0, 7, 0); // The first display is at <0, 0> matrix.setPosition(1, 6, 0); // The second display is at <1, 0> matrix.setPosition(2, 5, 0); // The third display is at <2, 0> matrix.setPosition(3, 4, 0); //... matrix.setPosition(4, 3, 0); //... matrix.setPosition(5, 2, 0); //... matrix.setPosition(6, 1, 0); //... matrix.setPosition(7, 0, 0);// And the last display is at <7, 0> // ... matrix.setRotation(0, 1); // The first display is horizontal matrix.setRotation(1, 1); //... matrix.setRotation(2, 1); //... matrix.setRotation(3, 1); //... matrix.setRotation(4, 1); //... matrix.setRotation(5, 1); //... matrix.setRotation(6, 1); //... matrix.setRotation(7, 1);// The same for the last displayRotation was necessary because the library still expects each 8x8 module to be individual modules with the pins on top and bottom, instead of on the sides like these are. This works only if the incoming data lines are on the right hand side when looking at the LEDsI hope this was helpful! If it was, consider giving it a thumbs up! And don't forget to like and sub... wait, this isn't a YouTube script! Sorry about that! Thanks for watching!

This MAX7219 is RED, BRIGHT, Great display and easy to use!If you are using the latest MD_MAX7219 {GitHub MajicDesigns/MD_MAX72XX} you may notice, that, your display looks odd (see my image)! Try adding this to your Arduino Sketch:#define HARDWARE_TYPE MD_MAX72XX::ICSTATION_HWComment or delete any other of the above #defines, ie //#define HARDWARE_TYPE MD_MAX72XX::PAROLA_HW// Arbitrary output pinsMD_Parola P = MD_Parola(HARDWARE_TYPE, DATA_PIN, CLK_PIN, CS_PIN, MAX_DEVICES);Marco Colli has made major changes to his code, so, many of the code examples, that, you find on the Internet will not work, correctly! You no longer need to edit the MD_MAX72xx.h file (can't anyway, totally revised). Many of the YouTube videos suggest, that, you edit this file, this no longer possible with the latest update, available at GitHub.I hope, that, this helps!

Average price. Two 4 character displays included. Very bright. Used as replacement for an existing design with no issues. Manufacturing seems solid. No problem daisy chaining them. See other reviews for proper Arduino drivers.

The module looks good but the circuit board is wider than 12.8cm at 13.15 cm. If you need this to fit precisely in an enclosure then you'll need to modify the opening to the 13.15 cm width.

The size of each of these devices is 5 inches long, 1.25 inches high and 0.5 inches thick. I used the code described by devil man and changed the hardware description as he described. I made one additional change. The is a statement #define MAX_DEVICES 11. By max devices the code means each individual unit of the module. There are 4 units in each module. So MAX_DEVICES needs to be a multiple of 4. Since I was using 4 modules, I changed MAX_DEVICES to 16. Then I found that I got inconsistent results with the modules connected by wires. I added some connectors to the output end of each module so I could plug each one into the other and every thing worked great with the Arduino Code. I wanted the displays to have a "Merry Christmas 2019" sign in my front window for next Christmas. They are too small for that use. I plan to use them on my HO train layout to make road side signs. I ordered a different larger unit which should work for my Christmas plans.

If I wasn't building some presents for Christmas these would go back to Amazon. I had to desolder and resolder headers in order for the parts to fit. As you can see the quality control is poor. I do not recommend this seller. I purchased 2 lots and between lots they used differrent components APG vs 1088AS dot matrix led panels. Some of the pin insulation material was broken on the support headers because they tried to force the panels down into a crooked solder job which also cause the board to bend. They all worked but unfurtunately it was a pain in my rear. Not worth the headache!!

I got a 2 pack of displays. One worked fine right away. The other had a row of LEDs stuck on the second module and the last 2 modules were not working. I nearly returned it but, on closer inspection I found that the third LED array (plug in part) was plugged in upside down (fits either way but only works one way) and a big blob of solder between 2 pins on the second module. In the end it works but there is no way it passed any quality check at manufacture. Buy at your own risk.

The media could not be loaded.  These are really great displays, simple plug and play for Max_72XX and the MD_Parola libraries, hardware set to FC16_HW, very glad to find these, good price and package very well, can't beat that.