HOW TO USE LED DISPLAY DRIVERS

Hello, readers welcome to the new post. Today we will discuss HOW TO USE LED DISPLAY DRIVERS. The display driver is ICs circuit that is used to make connections between eh controller like the microcontroller and display devices. The display driver normally gets programming commands and data through the use of serial and parallel communication interfacing. After this configuration, they generated certain values of the signal by using current volts timing demultiplexing, and the output is shown on display.

The main function of the LED driver is to control the current and volts given to a single LED in the display. in this post, we will discuss all the details and related parameters. So let’s get started

Table of Contents

HOW LED DRIVERS WORK

The LED driver operated to control the numerous LEDs at the same time. As we know LED is a current driver component, not a voltage control

Small changes in voltage can result in high currents. So for this module operation varies the current not volts.
It is a switch mode component that transforms the input volts value to such a volts value that has current passing in the led equally to drive the current of the led
The drive current of the LED is used to control its brightness, operation life, and battery charging time.
The drive current is less than the highest drive current of LED increases the operation life of LED
LED driver is the same as cruise control used in cars. Its main operation is to control the current movement of the LED.
If there is no LED driver connected to the led results in heating of the LED and unstable operation and at the end led can be damaged.
It indicates that without the led driver lead is nothing either it has high quality and good operation.
Mostly LED is used in fewer volts of DC. The LED driver is especially used to convert the high-value AC to the low-value DC that is used by led. In simple words, it is a rectifier for LED. Led operating volts are two to four volts of dc

TYPES OF LED DISPLAY DRIVERS

The main types of LED display drivers described here

7 Segment LED Driver

In these LED display driver combinations, logic circuits are used that get four bit of BCD input and produce 7 segment output signal to regulate the
These are LED display drivers that use a combinational logic circuit that accepts a 4-bit BCD input and generates seven output signals to control seven individual display segments.

Constant Current LED Driver

It is an inner circuit that controls every LED loop current and automatically set produced output DC volts to the least value need to make a high forward value

RGB LED Driver

It is used for control of the color of RGB LED and LED strips. Software with inner registers and SPI interfacing used to control the operations

White LED Driver

It is good for LED matrix control. These modules eliminate white light for backlighting and also have less noise.

Introduction to MAX7219 LED DISPLAY DRIVER

The MAX7219 comes with a compact structure, serial input, or output common-cathode display driver.
It can be connected with microprocessors having seven-segment numeric LED displays to eight digits. It also helps processors to connect with bar graph display or sixty-four single LED
Consists of an on-chip BCD code- B decoder, multiplex scan circuits, digital driver, and 8 x 8 SRAM that is used for data storing
It uses one outer resistance to adjust the segment current for all LEDs. The MAX7221 has compatibility with SPI communication protocol, QSPI, and microwire and has a value of slew-rate to operate to decrease EMI.
The simple four-wire serial interfacing link with all mutual ups. Single digits can be addressed and updated without rewriting the complete display.
It has features to choose code-B decoding or no-decide for every digit.
The module consists of one fifty microamperes low power shutdown mode, analog, and digital brightness control, and scan limit register which permits users to show from one to eight digits

MAX7219 LED DISPLAY DRIVER Features

Some features of this component are discussed here
Storage temperature is minus sixty-five to one-fifty centigrade
The operating temperature is zero to plus seventy
Data to segment delay time is 2.2ms
It consumes less power
The highest current to each segment pin is 100mA
The highest current for every DIGIT is 500mA
Operating volts is plus four to plus 5.5 volts
Operating volts are plus five volts

MAX7219 Pinout of MAX7219

The main pinout of the MAX7219 LED driver is discussed here. It has twenty-four pinout
Its pins are divided into different groups based on operation

COMMON CATHODE OF DISPLAY SEGMENTS

DIG1 is common gerund point for DGIT1 segments
DIG2 is common gerund point for DGIT2 segments
DIG3 is common gerund point for DGIT3 segments
DIG4 is common gerund point for DGIT4 segments
DIG5 is common gerund point for DGIT5 segments
DIG6 is common ground point for DGIT6 segments
DIG7 is common ground point for DGIT7 segments

SHARED Pins

GND is the ground pin
V+- here power supply connected

SHARED SEGMENT pins OF ALL EIGHT DIGITS

SEG A is used for all Digits SEGMENT A
SEG B is used for all Digits SEGMENT B
SEG c is used for all Digits SEGMENT C
SEG D is used for all Digits SEGMENT D
SEG E is used for all Digits SEGMENT E
SEG F is used for all Digits SEGMENT F
SEG G is used for all Digits SEGMENT G
SEG DP is used for all Digits SEGMENT DOT

Functional Pinout

DIN is serail data input pin configuriaon
LOAD is chip select or data shift pin
CLK is clock pinout
DOUT is the pin used to link 2nd chip in a series combination
ISET is the current output adjust pin

MAX7219 IC USes

It is used to control a large number of displays by connecting larger chips in a series of combination
It is used with 7 segment display and can control eight digits
It has a feature to link sixty-four LEDs through three pins
It reduces the input and output pins of the controller
Used for serial to parallel data conversion

How to connect MAX7219 LED DISPLAY DRIVER to 7-segment display

In the below figure, you can see the MAX7219 LED display driver connection with 7 segment display

MAX7219 LED DISPLAY DRIVER Working

This component operation is like a shift register. Through this module, at the start data is sent in serial communication and after that, all data is sent at once. There is a CS pin used to shift serial data transmission to output.

DIN pin used for data sending. Data is sent in form of bits by adjusting the clock of the chip for every bit
It stores serial data in the register till all data reach. After completion of data sending, we adjust the CS pin to shift all data stored in the register to output.
The data in output is the form through setting DIG0-7 and pins SEG0-7 high or low.
This high or low signal helps to on and off the single LED existing in the display
Two methods are used for programming this led driver first one is to use datasheet instructions for data transmission serial way. The second is the use of software