MAX7219X4

Features

• (4) MAX7219 8 digits, 7 Segment display modules
• 32 digits
  • 4 rows
  • 8 digits per row
• Can display decimal, hex values, some text values
• Each display has 8 of 7 segment LED displays
• "Blue" card
  • ebay search
  • Not compatible with red modules
• 3.3V interface operation
  • 3.3V to 5V Level shifter
• Requires both 3.3V and 5V power supplies
• 8 pin connector
• 95x95mm ODAS form factor
• (4) 6-32 mounting holes

J1 Connector

• 3.3V signal level
• 5V power to LEDs
• 1x8 right angle header mounted on rear of card

1. GND
2. GND
3. DOUT
4. CLK
5. CS
6. DIN
7. 3.3V
8. 5V

Programming

Arduino Drivers

• MAX7219X4 Land Boards Arduino GitHub repository
  • Uses Arduino LedControl library
    • Library writes to multiple 8-digit displays
  • Pins
    • Arduino UNO pin 12 is connected to the DataIn
    • Arduino UNO pin 11 is connected to the CLK
    • Arduino UNO pin 10 is connected to CS

Arduino Example Code

• LBMAX7219X4_ADDR
  • void writeHexDigit(uint8_t rowVal, uint8_t colVal, uint8_t digitVal) - Write Hexadecimal digit to location
• LBMAX7219X4
  • Displays Land-Boards across the LEDs on 4 rows of 8-digits MAX7219X4 card
  • "LAND-" (first line)
  • "BOARDS" (second line)
  • "PRESENTS" (third line)
  • "CARDS...", "AND CODE" (4th line)

Test

Test MAX7219X4 Card

• ArduinoInABox
• Wiring Table

AiB	Signal	MAX7219X4	Signal	Color
J5-25	GND	J1-1	GND	BLK
D11	J5-19	J1-4	CLK	YEL
D10	J5-21	J1-5	CS	WHT
D12	J5-17	J1-6	DIN	BLU
+3.3V	J5-1	J1-7	+3.3V	RED
VFILT	J9-1	J1-8	5V	ORG

Test Single Modules

• Arduino Sensor Shield

SenShld	Desc	MAX J1	Color
VCC	VCC	1	RED
GND	GND	2	BLK
D12	DATAIN	3	WHT
D10	CS	4	BRN
D11	CLK	5	YEL

"Red" Modules

• Incompatible pinouts
  • Flipped from blue modules

Mechanicals

Assembly Sheet

• MAX7219X4 Assembly Sheet