The 4017 Decade Counter IC

Oct 13, 2025 by wbrum.org 7 views

Introduction

In this article, we will explore the design of a 7-segment numeric counter that displays numbers 1-8 in a loop. This counter will be built using 4000-series ICs, which are readily available and suitable for this project. The counter will be designed to display the numbers 1-8 on a 7-segment LED numeric display.

Understanding 7-Segment Displays

A 7-segment display is a type of display that consists of seven segments, each representing a different digit. The segments are arranged in a specific pattern to form the digits 0-9. In this project, we will be using a 7-segment display to display the numbers 1-8.

Choosing the Right ICs

For this project, we will be using 4000-series ICs, which are a series of digital logic ICs produced by Texas Instruments. The 4000-series ICs are known for their high speed, low power consumption, and low cost. We will be using the 4017 decade counter IC, which is a popular choice for building counters.

The 4017 Decade Counter IC

The 4017 decade counter IC is a 14-pin IC that can be used to build a decade counter. It has a single input pin (CP) that is used to clock the counter, and a single output pin (Q) that is used to display the count. The 4017 IC also has a reset pin (R) that is used to reset the counter to zero.

Designing the Counter Circuit

To design the counter circuit, we will need to connect the 4017 IC to a 7-segment display and a reset switch. The circuit will consist of the following components:

1 x 4017 decade counter IC
1 x 7-segment display
1 x reset switch
1 x clock source (e.g. a button or a potentiometer)

Connecting the 4017 IC to the 7-Segment Display

To connect the 4017 IC to the 7-segment display, we will need to use a series of resistors and diodes to decode the output of the 4017 IC. The 7-segment display will be connected to the output of the 4017 IC, and the resistors and diodes will be used to decode the output and display the correct digit.

Decoding the Output of the 4017 IC

The 4017 IC has a single output pin (Q) that is used to display the count. However, the output of the 4017 IC is a binary code that needs to be decoded to display the correct digit. To decode the output, we will use a series of resistors and diodes to convert the binary code into a decimal code that can be displayed on the 7-segment display.

Using a 7-Segment Display Driver IC

To simplify the decoding process, we can use a 7-segment display driver IC such as the 7447 or 7448. These ICs have built-in decoding circuits that can be used to decode the output of the 4017 IC and display the correct digit on the 7-segment display.

Connecting the Reset Switch

To connect the reset switch, we will need to connect it to the reset pin (R) of the 4017 IC. The reset switch will be used to reset the counter to zero when it is pressed.

Connecting the Clock Source

To connect the clock source, we will need to connect it to the clock input pin (CP) of the 4017 IC. The clock source will be used to clock the counter and increment the count.

The Complete Circuit

The complete circuit will consist of the following components:

1 x 4017 decade counter IC
1 x 7-segment display
1 x reset switch
1 x clock source (e.g. a button or a potentiometer)
1 x 7447 or 7448 7-segment display driver IC (optional)

Schematic Diagram

The schematic diagram of the counter circuit is shown below:

  +---------------+
  |  4017 IC    |
  |  (Decade  |
  |   Counter)  |
  +---------------+
  |  Q  |  R  |  CP |
  |  ---|---|---|
  |  7447  |  Reset  |  Clock  |
  |  (7-Segment  |  Switch  |  Source  |
  |   Display  |          |          |
  |   Driver)  |          |          |
  +---------------+
  |  7-Segment  |
  |  Display    |
  +---------------+

Code

The code for the counter circuit is shown below:

#include <avr/io.h>
#include <avr/interrupt.h>
#define F_CPU 16000000UL
int main() {
// Initialize the 4017 IC
DDRB = 0xFF; // Set the output pins of the 4017 IC as outputs
PORTB = 0x00; // Set the output pins of the 4017 IC to low
// Initialize the 7447 IC (if used)
DDRD = 0xFF; // Set the output pins of the 7447 IC as outputs
PORTD = 0x00; // Set the output pins of the 7447 IC to low
// Connect the clock source to the clock input pin of the 4017 IC
DDRG = 0xFF; // Set the output pin of the clock source as an output
PORTG = 0x00; // Set the output pin of the clock source to low
// Connect the reset switch to the reset pin of the 4017 IC
DDRH = 0xFF; // Set the output pin of the reset switch as an output
PORTH = 0x00; // Set the output pin of the reset switch to low
// Main loop
while (1) {
// Clock the counter
PORTG = 0x01; // Set the output pin of the clock source to high
_delay_ms(10); // Delay for 10ms
PORTG = 0x00; // Set the output pin of the clock source to low
// Check if the reset switch is pressed
if (PINC &amp; 0x01) { // Check if the reset switch is pressed
  // Reset the counter to zero
  PORTB = 0x00; // Set the output pins of the 4017 IC to low
}

}
return 0;
}

Conclusion

In this article, we have designed a 7-segment numeric counter that displays numbers 1-8 in a loop. The counter is built using a 4017 decade counter IC and a 7-segment display driver IC (optional). The counter is clocked using a clock source (e.g. a button or a potentiometer) and reset using a reset switch. The complete circuit consists of the 4017 IC, 7-segment display, reset switch, clock source, and 7447 or 7448 7-segment display driver IC (optional). The code for the counter circuit is shown above.

Future Work

In the future, we can improve the counter circuit by adding more features such as:

Adding a display driver IC to simplify the decoding process
Adding a reset button to reset the counter to zero
Adding a clock source with a variable frequency to allow the user to adjust the clock speed
Adding a display with a higher resolution to display more digits

References

Texas Instruments. (n.d.). 4017 Decade Counter IC. Retrieved from https://www.ti.com/lit/ds/symlink/sn74hc4017.pdf
Texas Instruments. (n.d.). 7447 7-Segment Display Driver IC. Retrieved from https://www.ti.com/lit/ds/symlink/sn74ls47.pdf
Atmel. (n.d.). AVR Microcontroller User Guide. Retrieved from https://www.atmel.com/images/doc2545.pdf
Q&A: 7-Segment Numeric Counter for Numbers 1-8 =====================================================

Frequently Asked Questions

In this article, we will answer some of the most frequently asked questions about the 7-segment numeric counter for numbers 1-8.

Q: What is the purpose of the 7-segment numeric counter?

A: The 7-segment numeric counter is a digital circuit that displays numbers 1-8 in a loop. It is designed to be used in applications where a simple numeric display is required.

Q: What ICs are used in the 7-segment numeric counter?

A: The 7-segment numeric counter uses a 4017 decade counter IC and a 7447 or 7448 7-segment display driver IC (optional).

Q: How does the 7-segment numeric counter work?

A: The 7-segment numeric counter works by using the 4017 decade counter IC to count from 1 to 8 in a loop. The output of the 4017 IC is then decoded by the 7447 or 7448 7-segment display driver IC (optional) to display the correct digit on the 7-segment display.

Q: What is the clock source used in the 7-segment numeric counter?

A: The clock source used in the 7-segment numeric counter is a button or a potentiometer. The clock source is used to clock the counter and increment the count.

Q: How is the reset switch used in the 7-segment numeric counter?

A: The reset switch is used to reset the counter to zero when it is pressed. The reset switch is connected to the reset pin of the 4017 IC.

Q: Can the 7-segment numeric counter be used in other applications?

A: Yes, the 7-segment numeric counter can be used in other applications such as:

Displaying time
Displaying temperature
Displaying data from sensors
Displaying data from other digital circuits

Q: What are the advantages of using the 7-segment numeric counter?

A: The advantages of using the 7-segment numeric counter include:

Simple design
Low cost
High accuracy
Easy to use

Q: What are the disadvantages of using the 7-segment numeric counter?

A: The disadvantages of using the 7-segment numeric counter include:

Limited display range (1-8)
Limited resolution (7-segment display)
Limited flexibility (fixed clock source and reset switch)

Q: Can the 7-segment numeric counter be modified to display other numbers?

A: Yes, the 7-segment numeric counter can be modified to display other numbers by changing the decoding circuit and the display driver IC.

Q: Can the 7-segment numeric counter be used with other types of displays?

A: Yes, the 7-segment numeric counter can be used with other types of displays such as LCD displays, LED displays, and VFD displays.

Q: What are the limitations of the 7-segment numeric counter?

A: The limitations of the 7-segment numeric counter include:

Limited display range (1-8)
Limited resolution (7-segment display)
Limited flexibility (fixed clock source and reset switch)
Limited accuracy (dependent on the clock source and reset switch)

Conclusion

In this article, we have answered some of the most frequently asked questions about the 7-segment numeric counter for numbers 1-8. The 7-segment numeric counter is a simple and low-cost digital circuit that displays numbers 1-8 in a loop. It can be used in a variety of applications and can be modified to display other numbers and types of displays.

References

Texas Instruments. (n.d.). 4017 Decade Counter IC. Retrieved from https://www.ti.com/lit/ds/symlink/sn74hc4017.pdf
Texas Instruments. (n.d.). 7447 7-Segment Display Driver IC. Retrieved from https://www.ti.com/lit/ds/symlink/sn74ls47.pdf
Atmel. (n.d.). AVR Microcontroller User Guide. Retrieved from https://www.atmel.com/images/doc2545.pdf