Features
(4) MAX7219 8 digits, 7 Segment display modules
32 digits
Can display decimal, hex values, some text values
Each display has 8 of 7 segment LED displays
"Blue" card
3.3V interface operation
Requires both 3.3V and 5V power supplies
8 pin connector
95x95mm ODAS form factor
(4) 6-32 mounting holes
Connectors
J1 Connector
3.3V signal level
5V power to LEDs
1x8 right angle header mounted on rear of card
GND
GND
DOUT
CLK
CS
DIN
+3.3V
+5V
J2 (Rev 2 and higher)
+5V
DIN
CS
CLK
DOUT
GND
Programming
Arduino Programming
Arduino Drivers
Arduino Example Code
LBMAX7219X4_ADDR
LBMAX7219X4_ADDR
void writeHexDigit(uint8_t rowVal, uint8_t colVal, uint8_t digitVal) - Write Hexadecimal digit to location
8 columns, 4 rows
rowVal = 0 is top row in display
colVal = 0 = left character
LBMAX7219X4
LBMAX7219X4
Displays Land-Boards channel intro video 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)
CircuitPython Programming
class adafruit_max7219.bcddigits.BCDDigits(spi: SPI, cs: DigitalInOut, nDigits: int = 1)[source]
Basic support for display on a 7-Segment BCD display controlled by a Max7219 chip using SPI.
Parameters
spi (SPI) – an spi busio or spi bitbangio object
cs (DigitalInOut) – digital in/out to use as chip select signal
nDigits (int) – number of led 7-segment digits; default 1; max 8
VHDL Code
instance: MAX7219
generic map(
devices => 2,
intensity => (16#1#, 16#3#)
)
port map (
clk => clock,
data_vector => x"FEDCBA9876543210",
clk_out => MAX7219_CLK,
data_out => MAX7219_DATA,
load_out => MAX7219_LOAD,
reset_n => globalResetN
);
Test
Test single 8-digit modules
Test MAX7219X4 card with (4) 8-digit modules
Test Single MAX7219 Modules
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
Test MAX7219X4 Card
Signal
AiB
MAX7219X4
Signal
Color
GND
J5-25
J1-1
GND
BLK
D10
J5-21
J1-5
CS
WHT
D11
J5-19
J1-4
CLK
YEL
D12
J5-17
J1-6
DIN
BLU
+3.3V
J5-1
J1-7
+3.3V
RED
VFILT
J9-1
J1-8
5V
ORG
"Red" Modules
Incompatible pinouts
Do not work with this card
Flipped from blue modules
Mechanicals
Revision History
Rev 2
Add 5V interface connector - J2
Card can be driven from one of the two interfaces
5V interface does not require 3.3V
+5V
DIN
CS
CLK
DOUT
GND
Rev 1
Tested/works
Requires 3.3V power and signal levels
Requires 5V power
Assembly Sheet