MAX7219 is an IC designed to control 8×8 Dot Matrix LEDs, 7-segment LEDs up to 8 digits or 64-point individual LEDs.
MAX7219 is a 24-pin IC available in various packages and selected depending on the requirements. Descriptions for each pin are given below :
|COMMON CATHODE OF DISPLAY SEGMENTS|
|2||DIG0- Common ground for all eight segments of DIGIT0|
|11||DIG1- Common ground for all eight segments of DIGIT1|
|6||DIG2- Common ground for all eight segments of DIGIT2|
|7||DIG3- Common ground for all eight segments of DIGIT3|
|3||DIG4- Common ground for all eight segments of DIGIT4|
|10||DIG5- Common ground for all eight segments of DIGIT5|
|5||DIG6- Common ground for all eight segments of DIGIT6|
|8||DIG7- Common ground for all eight segments of DIGIT7|
|19||V+- Power Supply|
|SHARED SEGMENT TERMINAL OF ALL EIGHT DIGITS|
|14||SEG A – SEGEMTENT A of all DIGITS|
|16||SEG B – SEGEMTENT B of all DIGITS|
|20||SEG C – SEGEMTENT C of all DIGITS|
|23||SEG D – SEGEMTENT D of all DIGITS|
|21||SEG E – SEGEMTENT E of all DIGITS|
|15||SEG F – SEGEMTENT F of all DIGITS|
|17||SEG G – SEGEMTENT G of all DIGITS|
|22||SEG DP – SEGEMTENT DOT of all DIGITS|
|1||DIN – Serial Data Input Pin|
|12||LOAD(CS) – Chip Select or Data shift pin|
|13||CLK – Clock Pin|
|24||DOUT – Pin used to Connect Second chip serially|
|18||ISET – current output adjust pin|
Features and Specifications
- Operating voltage range: +4.0 to +5.5V
- Recommended operating voltage: +5V
- Maximum supply voltage: 6V
- Maximum current allowed to draw through each segment pin: 100mA
- Maximum current allowed to through each DIGIT ground pin: 500mA
- Low power consumption
- Data-to-Segment Delay Time: 2.2mSec
- Operating temperature: 0°C to +70°C
- Storage Temperature: -65°C to +150°C
ICs that are similar or similar in function to MAX7219 are 74HC595 Shift Register ICs
MAX7219 IC is Used For
- This IC is basically used where if we want to convert serial data to parallel data.
- This chip is used to reduce the use of I / O pins from the controller or processor
- Used to control 64 LEDs using only 3 PIN
- Used to control the Dot Matrix 8 x 8 display
- Used for 7 Segment display controllers. Chip or IC MAX7219 can control 7 Segments of up to 8 Digits
- Can be used to control more 7 Segment displays by connecting more chips or IC MAX7219 serially
How to use MAX7219 IC
This chip is used similar to Shift Register. First we have to send data serially to the chip. After all data has been sent, we need to tell the chip to move this serial data to the output by activating the CS pin. The working procedure step by step goes like below.
- First connect the DIN, CS and CLK pin. These three pins are important for controlling the chip.
- Next is to choose a resistor for the ISET pin. As we know that there are no standard parameters for 7 segment displays on the market. They have different voltage and current settings. For the correct display, we need to select the appropriate resistor using the following table.
- There are two ways to use this chip. One of them is to follow the instructions given in the datasheet to send data little by little. The second way is to use a library specifically written for the MAX7219 chip or IC. Using a library is the easiest way to get the results you need. With libraries, we only need to enter the data needed to be sent without the need to think about how it works.
- We need to send data to the chip or IC MAX7219 via the DIN pin. Data is sent Bit by Bit by setting the clock chip for each bit. The chip stores serial data to its register until all data is received. After completing data transmission, we need to set the CS pin of the chip to shift all data stored in its register to the output.
- After the data is released by the chip, it will turn on the appropriate LED to display the results.
Example of Use
The following are some examples of usage or examples of the MAX7219 program for display control :
- Programming MAX7219 Dot Matrix 4 In 1 Display Module with Arduino
- Kontroller MAX7219 Display 7 Segment 8 Digit Modul dengan menggunakan Arduino
- Kontroller Display Peralatan Elektronik