I strongly recommend buying a matrix display with the MAX7219 already integrated. This saves you a lot of work, a lot of cable clutter and sleepless nights.<\/p>\n\n\n\n I got these:MAX7219 Dot Matrix Display Module Single-Chip Control LED Module DIY Kit for Arduino with 5pin Line<\/a>* That’s two matrix displays for around ten bucks. I think that’s a good price.<\/p>\n\n\n\n The circuit is very simple. The display gets power through the GND and 5V +. In addition, three data lines are required. The option of switching several displays in series is super useful.<\/p>\n\n\n\n To control the Max7219, the LEDControl library has to be installed. Click Sketch>Libraries>Manage libraries<\/em> and search for LEDControl<\/em>. Install the current version of the library.<\/p>\n\n\n\n You can also find this example under File > Examples > LedControl > LCDemoMatrix<\/em>.<\/p>\n\n\n\n lc.setIntensity(0,8); lc.clearDisplay(0); And what are you going to do with it now? How about a cool Arduino Halloween LED matrix pumpkin<\/a> or an Arduino open fire<\/a>? \ud83d\ude42<\/p>\n","protected":false},"excerpt":{"rendered":"![\"\"](\"https:\/\/starthardware.org\/en\/wp-content\/uploads\/2020\/01\/Arduino-Max7219-LED-Matrix-Display.jpg\")
<\/figure>\n\n\n\nCircuit<\/h2>\n\n\n\n
![\"Arduino](\"https:\/\/starthardware.org\/en\/wp-content\/uploads\/2020\/01\/arduino-led-matrix-max7219-schaltplan-schaltung-circuit-1.jpg\")
<\/figure>\n\n\n\n![\"\"](\"https:\/\/starthardware.org\/en\/wp-content\/uploads\/2020\/01\/arduino-led-matrix-max7219-schaltplan-schaltung-circuit-chain-1024x315.jpg\")
<\/figure>\n\n\n\nArduino Matrix Display Code<\/h2>\n\n\n\n
\/\/We always have to include the library\n#include \"LedControl.h\"\n\n\/*\n Now we need a LedControl to work with.\n ***** These pin numbers will probably not work with your hardware *****\n pin 12 is connected to the DataIn \n pin 11 is connected to the CLK \n pin 10 is connected to LOAD \n We have only a single MAX72XX.\n *\/\nLedControl lc=LedControl(12,11,10,1);\n\n\/* we always wait a bit between updates of the display *\/\nunsigned long delaytime=100;\n\nvoid setup() {\n \/*\n The MAX72XX is in power-saving mode on startup,\n we have to do a wakeup call\n *\/\n lc.shutdown(0,false);\n \/* Set the brightness to a medium values *\/\n lc.setIntensity(0,8);\n \/* and clear the display *\/\n lc.clearDisplay(0);\n}\n\n\/*\n This method will display the characters for the\n word \"Arduino\" one after the other on the matrix. \n (you need at least 5x7 leds to see the whole chars)\n *\/\nvoid writeArduinoOnMatrix() {\n \/* here is the data for the characters *\/\n byte a[5]={B01111110,B10001000,B10001000,B10001000,B01111110};\n byte r[5]={B00111110,B00010000,B00100000,B00100000,B00010000};\n byte d[5]={B00011100,B00100010,B00100010,B00010010,B11111110};\n byte u[5]={B00111100,B00000010,B00000010,B00000100,B00111110};\n byte i[5]={B00000000,B00100010,B10111110,B00000010,B00000000};\n byte n[5]={B00111110,B00010000,B00100000,B00100000,B00011110};\n byte o[5]={B00011100,B00100010,B00100010,B00100010,B00011100};\n\n \/* now display them one by one with a small delay *\/\n lc.setRow(0,0,a[0]);\n lc.setRow(0,1,a[1]);\n lc.setRow(0,2,a[2]);\n lc.setRow(0,3,a[3]);\n lc.setRow(0,4,a[4]);\n delay(delaytime);\n lc.setRow(0,0,r[0]);\n lc.setRow(0,1,r[1]);\n lc.setRow(0,2,r[2]);\n lc.setRow(0,3,r[3]);\n lc.setRow(0,4,r[4]);\n delay(delaytime);\n lc.setRow(0,0,d[0]);\n lc.setRow(0,1,d[1]);\n lc.setRow(0,2,d[2]);\n lc.setRow(0,3,d[3]);\n lc.setRow(0,4,d[4]);\n delay(delaytime);\n lc.setRow(0,0,u[0]);\n lc.setRow(0,1,u[1]);\n lc.setRow(0,2,u[2]);\n lc.setRow(0,3,u[3]);\n lc.setRow(0,4,u[4]);\n delay(delaytime);\n lc.setRow(0,0,i[0]);\n lc.setRow(0,1,i[1]);\n lc.setRow(0,2,i[2]);\n lc.setRow(0,3,i[3]);\n lc.setRow(0,4,i[4]);\n delay(delaytime);\n lc.setRow(0,0,n[0]);\n lc.setRow(0,1,n[1]);\n lc.setRow(0,2,n[2]);\n lc.setRow(0,3,n[3]);\n lc.setRow(0,4,n[4]);\n delay(delaytime);\n lc.setRow(0,0,o[0]);\n lc.setRow(0,1,o[1]);\n lc.setRow(0,2,o[2]);\n lc.setRow(0,3,o[3]);\n lc.setRow(0,4,o[4]);\n delay(delaytime);\n lc.setRow(0,0,0);\n lc.setRow(0,1,0);\n lc.setRow(0,2,0);\n lc.setRow(0,3,0);\n lc.setRow(0,4,0);\n delay(delaytime);\n}\n\n\/*\n This function lights up a some Leds in a row.\n The pattern will be repeated on every row.\n The pattern will blink along with the row-number.\n row number 4 (index==3) will blink 4 times etc.\n *\/\nvoid rows() {\n for(int row=0;row<8;row++) {\n delay(delaytime);\n lc.setRow(0,row,B10100000);\n delay(delaytime);\n lc.setRow(0,row,(byte)0);\n for(int i=0;i<row;i++) {\n delay(delaytime);\n lc.setRow(0,row,B10100000);\n delay(delaytime);\n lc.setRow(0,row,(byte)0);\n }\n }\n}\n\n\/*\n This function lights up a some Leds in a column.\n The pattern will be repeated on every column.\n The pattern will blink along with the column-number.\n column number 4 (index==3) will blink 4 times etc.\n *\/\nvoid columns() {\n for(int col=0;col<8;col++) {\n delay(delaytime);\n lc.setColumn(0,col,B10100000);\n delay(delaytime);\n lc.setColumn(0,col,(byte)0);\n for(int i=0;i<col;i++) {\n delay(delaytime);\n lc.setColumn(0,col,B10100000);\n delay(delaytime);\n lc.setColumn(0,col,(byte)0);\n }\n }\n}\n\n\/* \n This function will light up every Led on the matrix.\n The led will blink along with the row-number.\n row number 4 (index==3) will blink 4 times etc.\n *\/\nvoid single() {\n for(int row=0;row<8;row++) {\n for(int col=0;col<8;col++) {\n delay(delaytime);\n lc.setLed(0,row,col,true);\n delay(delaytime);\n for(int i=0;i<col;i++) {\n lc.setLed(0,row,col,false);\n delay(delaytime);\n lc.setLed(0,row,col,true);\n delay(delaytime);\n }\n }\n }\n}\n\nvoid loop() { \n writeArduinoOnMatrix();\n rows();\n columns();\n single();\n}<\/code><\/pre>\n\n\n\nUseful commands from the LedControl library<\/h2>\n\n\n\n
LedControl lc=LedControl(12,11,10,1);<\/code>
Creates a display object and transfers the connected pins and the number of display modules<\/p>\n\n\n\nlc.shutdown(0,false);<\/code>
Wakes the display from energy saving mode<\/p>\n\n\n\n
Sets the brightness of the display. (Unfortunately, the range of values is unknown to me.)<\/p>\n\n\n\n
Deletes the display 0.<\/p>\n\n\n\nlc.setRow(0,row,B01111110);
<\/code>Writes a byte line by line (values 0 – 255) in the row row (value range 0 – 7).<\/p>\n\n\n\nlc.setColumn(0,col,B10100000);
<\/code>Writes one byte (values 0 – 255) into the col column (value range 0 – 7).<\/p>\n\n\n\nlc.setLed(0,row,col,true);
<\/code>Switches on an LED in display 0 at row, col. (Values true and false).<\/p>\n\n\n\n