The Engineering Projects

Interfacing of Arduino with 74HC595 & 74HC165

Hello friends, I hope you all are doing great. In today's tutorial, I am going to show you How to Interface Arduino with 74HC595 & 74HC165. I have already interfaced these shift registers separately with Arduino. In the first tutorial we have seen Arduino 74HC595 Interfacing in which I have discussed How to increase the output pins of Arduino using 74HC595. After that in second tutorial we have seen Arduino 74HC165 Interfacing where we have increased the input pins of Arduino. So, now we are gonna interface both of these shift registers with Arduino UNO and will increase both input and output pins of Arduino. I have also given the Proteus simulations for download at the end of this tutorial along with Arduino code. So, lets get started with Interfacing of Arduino with 74HC595 & 74HC165:

Interfacing of Arduino with 74HC595 & 74HC165

• First of all, you need to design a Proteus Simulation as shown in below figure:

• As you can see in above figure, I have used 74HC165 & 74HC595 and interfaced its pins with Arduino UNO.

• I could use same clock for these shift registers but it would have made the code quite complex.
• That's why I have used separate clock pins and I have used the below code to reflect the input on output.

#define NUMBER_OF_SHIFT_CHIPS   1
#define DATA_WIDTH   NUMBER_OF_SHIFT_CHIPS * 8
#define TotalIC 2
#define TotalICPins TotalIC * 8

int LoadPin    = 8;
int EnablePin  = 9;
int DataPin    = 11;
int ClockPin   = 12;

int RCLK = 5;
int SER = 6;
int SRCLK = 7;

unsigned long pinValues;
unsigned long oldPinValues;
boolean Data[TotalICPins];

void setup()
{
    Serial.begin(9600);

    pinMode(LoadPin, OUTPUT);
    pinMode(EnablePin, OUTPUT);
    pinMode(ClockPin, OUTPUT);
    pinMode(DataPin, INPUT);

    digitalWrite(ClockPin, LOW);
    digitalWrite(LoadPin, HIGH);
    Serial.println("Visit us at www.TheEngineeringProjects.com");
    Serial.println();
    pinMode(SER, OUTPUT);
    pinMode(RCLK, OUTPUT);
    pinMode(SRCLK, OUTPUT);

    ClearBuffer();
    
    pinValues = read_shift_regs();
    print_byte();
    oldPinValues = pinValues;
}

void loop()
{
    pinValues = read_shift_regs();

    if(pinValues != oldPinValues)
    {
        print_byte();
        oldPinValues = pinValues;
    }

}

unsigned long read_shift_regs()
{
    long bitVal;
    unsigned long bytesVal = 0;

    digitalWrite(EnablePin, HIGH);
    digitalWrite(LoadPin, LOW);
    delayMicroseconds(5);
    digitalWrite(LoadPin, HIGH);
    digitalWrite(EnablePin, LOW);

    for(int i = 0; i < DATA_WIDTH; i++)
    {
        bitVal = digitalRead(DataPin);
        bytesVal |= (bitVal << ((DATA_WIDTH-1) - i));

        digitalWrite(ClockPin, HIGH);
        delayMicroseconds(5);
        digitalWrite(ClockPin, LOW);
    }

    return(bytesVal);
}

void print_byte() { 
  byte i; 

  Serial.println("*Shift Register Values:*\r\n");

  for(byte i=0; i<=DATA_WIDTH-1; i++) 
  { 
    Serial.print("P");
    Serial.print(i+1);
    Serial.print(" "); 
  }
  Serial.println();
  for(byte i=0; i<=DATA_WIDTH-1; i++) 
  { 
    
    Serial.print(pinValues >> i & 1, BIN); 
    Data[i] = pinValues >> i & 1, BIN;
    //if(BinaryValue == 1){Data[i] = HIGH;}
    //if(BinaryValue == 0){Data[i] = LOW;}
    UpdateData();
    if(i>8){Serial.print(" ");}
    Serial.print("  "); 
    
  } 
  
  Serial.print("\n"); 
  Serial.println();Serial.println();

}

void ClearBuffer()
{
    for(int i = TotalICPins - 1; i >=  0; i--)
    {
       Data[i] = LOW;
    }
    UpdateData();
} 

void UpdateData()
{
   digitalWrite(RCLK, LOW);
   for(int i = TotalICPins - 1; i >=  0; i--)
   {
        digitalWrite(SRCLK, LOW);   
        digitalWrite(SER, Data[i]);
        digitalWrite(SRCLK, HIGH);

  }
  digitalWrite(RCLK, HIGH);
}

• In the above code, I have used Number_of_Shift_Chips 1 and it means I am using 1 chip each, so in total 2 chips.
• Now get hex file from Arduino software and upload it in your Proteus software.
• Run your simulation and if everything goes fine then you will get something as shown in below figure:

• You can see in above figure that all those LED outputs are ON which has HIGH inputs.
• I have also attached a Virtual Terminal with Arduino to have a look at the input bits.
• Now let's add 2 chips of 74HC165 and 74HC959, so design a simple simulation as shown in below figure:

• Now in your above code change the Number of Shift chips from 1 to 2, as now we are using 2 chips each.
• Upload your hex file and if everything goes fine then you will get similar results:

• So, that's how you can easily increase input and output pins of Arduino UNO.
• I have just designed a simple code but you can work on it and can control these inputs separately as well.
• You can interface different digital sensors on these input pins and can control motors, relays, solenoids etc. at output pins.
• You can download both of these Proteus Simulations along with Arduino code by clicking the below button, but I would suggest you to dwsign it on yoru own so that you could learn from mistakes.

[dt_default_button link="https://theengineeringprojects.com/ArduinoProjects/Interfacing%20of%20Arduino%20with%2074HC595%20&%2074HC165.zip" button_alignment="default" animation="fadeIn" size="medium" default_btn_bg_color="" bg_hover_color="" text_color="" text_hover_color="" icon="fa fa-chevron-circle-right" icon_align="left"]Download Proteus Simulation & Arduino Code [/dt_default_button]

So, that was all about Interfacing of Arduino with 74HC595 & 74HC165. I hope you can now easily simulate it. If you have any questions then ask in comments and I will try my best to resolve them. Thanks for reading. Take care !!! :)

Arduino 74HC595 Interfacing: Increase Output Pins

Hello friends, I hope you all are doing great. In today's tutorial, I am going to show you Arduino 74HC595 Interfacing and we will have a loook at How to Increase Arduino Output Pins with 74HC595. Suppose you are working on some project where you need to control 20 LEDs with Arduino UNO and you know we will 12 digital Pins so we can't control all of these 20 LEDs with Arduino UNO. We can use Arduino Mega as well but if we wanna stick to Arduino UNO then we need to increase its Output Pins and we will use 74HC595 for that purpose. You should read this basic Introduction to 74HC595, it will help you to better understand this shift register. It's a Serial In Parallel Out Shift register and we will give it value serially from single Pin of Arduino and it will output that data to 8 output pins. Moreover, we can also connect these registers in parallel to increase the output pins even further. So, let's have a look at Arduino 74HC595 Interfacing:

Arduino 74HC595 Interfacing

• As I told earlier 74HC595 is a serial In Parallel Out Shift Register and is used to increase the output pins of Arduino.
• I am gonna use Proteus software and we will design its simulation and then will check out How it works.
• So, design a simple circuit as shown in below figure:

• As you can see in above figure, I have done the following connections between Arduino and HC595:
  • Pin # 5 of Arduino ==> ST_CP
  • Pin # 6 of Arduino ==> DS
  • Pin # 7 of Arduino ==> SH_CP
  • All output pins of 74HC595 are connected to LEDs.

• Now upload the below Arduino code and get your hex file.

int RCLK = 5;
int SER = 6;
int SRCLK = 7;

#define TotalIC 1
#define TotalICPins TotalIC * 8

boolean Data[TotalICPins];

void setup()
{
  pinMode(SER, OUTPUT);
  pinMode(RCLK, OUTPUT);
  pinMode(SRCLK, OUTPUT);

  ClearBuffer();
}              


void loop()
{
   for(int i = TotalICPins - 1; i >=  0; i--)
   {
      Data[i] = HIGH;
      UpdateData();
      delay(300);
      ClearBuffer();
   }

   for(int i = 1;i < TotalICPins - 1;  i++)
   {
      Data[i] = HIGH;
      UpdateData();
      delay(300);
      ClearBuffer();
   }
   
}

void ClearBuffer()
{
    for(int i = TotalICPins - 1; i >=  0; i--)
    {
       Data[i] = LOW;
    }
    UpdateData();
} 

void UpdateData()
{
   digitalWrite(RCLK, LOW);
   for(int i = TotalICPins - 1; i >=  0; i--)
   {
        digitalWrite(SRCLK, LOW);   
        digitalWrite(SER, Data[i]);
        digitalWrite(SRCLK, HIGH);

  }
  digitalWrite(RCLK, HIGH);
}

• The code is quite simple but let me explain it a bit.
• First of all we have given names to our 3 Pins connected to Arduino UNO.
• After that we have made all those 3 Pins as OUTPUT as we are gonna send the data.
• We are using single chip of 74HC595 that's why I have made it 1.
• In the UpdateData function, you can see we have to make RCLK Low and after that we have sent our data.
• But for sending each bit of Data we have to make SRCLK from LOW to High.
• SER is our Serial IN from Arduino to 74HC595.
• So, in loop section, I am simply sending HIGH from first Pin to Last and then from last Pin to first and we are getting below results:

• Now let's have a look at How to connect two 74HC595 chips in parallel to increase the output pins to 16.
• I have also given these Proteus simulations for download at the end of this tutorial but I would recommend you to design them on your own so that you got better understanding of this shift register.

Arduino 74HC595 Interfacing: 2 Chips in Parallel

• Now we are gonna place two shift registers in parallel and we will be able to control 16 outputs from single Arduino Pin.
• Although we are using 3 Arduino Pins but the data is sent through Pin # 6 of Arduino and Pin # 5 and 7 are CLK Pins.
• Now design a circuit as shown in below figure:

• Now in Arduino Code, you just need to change the TotalIC to 2 and as you have seen we have already multiplied it with 8 so now our for loop will move from 0 to 15.
• Pin # 5 and 7 will simply connected to same pins of second shift register but DS will be connected to Q7' of first shift register.
• Now get your hex file from Arduino software and if everything goes fine then you will get something as shown in below figure:

• Now let's make it a bit more complex by adding 4 shift registers in parallel.
• So, design a Proteus Simulation as shown in below figure:

• We have followed the same principal, Q7' of second chip is connected to DS to 3rd chip and goes on.
• I have placed these default Pins instead of connecting the wires, it works the same.
• If this image is not clear then open it in new tab and zoom out to check the connections.
• Now in your Arduino code, you need to change the TotalIC to 4, as now we are using four chips.
• Get your Hex File and run Proteus simulation and if everything goes fine then you will get similar results:

• So, that's How you can quite easily do the Arduino 74HC595 Interfacing and can increase Arduino outputs as much as you want.
• You can download these Proteus Simulations along with code by clicking the below button:

[dt_default_button link="https://www.theengineeringprojects.com/ArduinoProjects/Arduino 74HC595 Interfacing.rar" button_alignment="default" animation="fadeIn" size="medium" default_btn_bg_color="" bg_hover_color="" text_color="" text_hover_color="" icon="fa fa-chevron-circle-right" icon_align="left"]Download Proteus Simulation & Arduino Code[/dt_default_button]

• I have also designed this YouTube video to give you a better understanding of Arduino 74HC595 Interfacing:

So, that was all for today. I hope you have enjoyed this Arduino 74Hc595 Interfacing. If you have any questions, then ask in comments and I will try my best to resolve them. In my coming tutorial, I will show you How to increase the Arduino Input Pins. So stay tuned and have fun. :)

Introduction to 74HC595

Hello everyone! I hope you will be absolutely fine and having fun. Today, I am going to explain all of you about Introduction to 74HC595. It is basically a shift register. It has an ability to store and to shift the data of 8 bits. First of all the data is written on the register serially and then it goes to the storage register. All of the output lines are controlled by this register. 74HC595 register is a very high speed device based on Complementary Metal Oxide Semiconductor (CMOS). 8 bit data register receives the data from the input DS. This data is then transferred from the input shift register to the output shift register. 74HC595 has a vey wide range of applications in daily life. It can be used as serial to parallel data converter, can receive and keeps the data for a long time etc. Moreover, It can be used in home appliances, for the industrial management, as computer peripheral. We will discuss further about this register later in this tutorial.

Introduction to 74HC595

74HC595 is a shift register having and eight bit storage register and an eight bit shift register. The data is written first and then stored into the device. It is high speed CMOS device. The data is usually entered in a serial format. Storage register is used to control the output lines of 74HC595. It has different real life applications e.g. in home appliances, computer peripherals, serial to parallel converter etc.

1. 74HC595 Pinout

• It has 16 pins in total out which eight are on left side and the remaining on the right side of the structure.
• The different function is associated with each of the pin.
• Some of the pins acts as an input to this device and receives data serially and transfer to the output pins to observe the received data.
• The pin diagram for 74HC595 is shown in the figure below:

• DS pin acts and receives the serial data.
• All of the lines with prefix Q acts as the output lines.

2. 74HC595 Pin Configuration

• In this section if the tutorial Introduction to 74HC595, I will tell you about the functions associated with each of the individual pin of 74HC595.
• All of the associated functions are describes in the table given below.

3. Functioning Diagarm

• The proper functional diagram of the shift register 74HC595 is shown in the figure below.

• From the above figure you can see that SHCP, master reset (MR) and the input DS are connected to 8 stage shift register.
• Pin number 12 i.e. STCP is connected to 8 bit storage register.
• The output enable (OE) is connected to 3 state outputs.

4. 74HC595 Functional Description

•  In this section of the tutorial Introduction to 74HC595, I will tell you about the functions of each line of the 8 bit shift register 74HC595.
• Complete description of the functions of 74HC595 is given in the table shown below.

5. 74HC595 Timing Diagram

• The arrow in the upward direction shows the rising edge of the each wave either received or applied.
• The shape of the signals applied and received and their relation with each other is shown in the figure below.

5. 74HC595 Logic Diagram

• The logic diagram for 74HC595 8 bit shift register is shown in the figure below.

• You can see that there are 8 different stages from 0 to 7 and latches are there in the logic diagram of 74HC595.
• Output enable (OE) and master reset (MR) are connected to latches with an inverted sign usually known as bubble.

6. 74HC595 Current/Voltage Rating

• The current, power and voltage rating along with their values and system international units are shown in the table given below.
• The values of operating temperature and storage temperature are also shown in the figure below.

7. 74HC595 Proteus Simulation

• I have a Proteus simulation for continuous control of the different LED's using 74HC595.
• The screenshot of the simulation is shown in the figure below.

• The complete Arduino source code is shown below.
• You need to just upload .hex file of this code into the Arduino of Proteus and run the simulation.

int RCLK = 5;
int SER = 6;
int SRCLK = 7;

#define TotalIC 1
#define TotalICPins TotalIC * 8

boolean Data[TotalICPins];

void setup()
{
  pinMode(SER, OUTPUT);
  pinMode(RCLK, OUTPUT);
  pinMode(SRCLK, OUTPUT);

  ClearBuffer();
}              


void loop()
{
   for(int i = TotalICPins - 1; i >=  0; i--)
   {
      Data[i] = HIGH;
      UpdateData();
      delay(300);
      ClearBuffer();
   }

   for(int i = 1;i < TotalICPins - 1;  i++)
   {
      Data[i] = HIGH;
      UpdateData();
      delay(300);
      ClearBuffer();
   }
   
}

• The running form of the above simulation is shown in the GIF below.

• You can download the complete simulation as well as the complete Arduino source code, here by clicking on the button below.

Proteus Simulation & Arduino Code

• Just download .rar file, extract it and enjoy the complete package having both Arduino source code as well as Proteus simulation.

So that is all from the tutorial Introduction to 74HC595. I hope you really enjoyed this tutorial. If you face any sort of problem regarding any thing, you can ask me anytime in comments without even feeling any kind of hesitation. I will try my level to entertain you and to solve your issues in a better way, if possible. Our entire team is 24/7 here to entertain you and to solve your issues in a way or the other. I will explore different IC's in my later tutorials and will surely share all them with all of as you as well. So, till then, Take Care :)