Must Know 74hc595 使い方 Article

シフトレジスタ(74HC595)の使い方 from www.chibiegg.net

Introduction

The 74hc595 is a shift register integrated circuit that allows you to control multiple output pins using only a few input pins. It's commonly used in electronic projects to expand the number of available pins on microcontrollers like the Arduino.

What is a Shift Register?

A shift register is an electronic circuit that can store and transfer data. It consists of a chain of flip-flops, where each flip-flop stores one bit of data. When you shift data into the shift register, the bits are transferred from one flip-flop to the next, effectively creating a longer binary number.

The 74hc595 Pinout

The 74hc595 has 16 pins, which are divided into three groups: power supply, input, and output. The power supply pins are VCC and GND, which provide the IC with the necessary voltage and ground. The input pins include SER (serial input), SRCLK (shift register clock), and RCLK (register clock), while the output pins are Q0 to Q7.

How to Use the 74hc595

To use the 74hc595, you need to connect the input pins to your microcontroller and the output pins to the components you want to control. The SER pin receives the data from the microcontroller, while the SRCLK and RCLK pins control the transfer of data into the shift register and the output register, respectively.

Example Project: LED Matrix

One common project that uses the 74hc595 is an LED matrix. By connecting multiple LEDs to the output pins, you can create a display that can show text, images, or animations. To control the LEDs, you need to send the data for each row of the matrix to the shift register, and then transfer the data to the output register to light up the corresponding LEDs.

Tips for Using the 74hc595

When using the 74hc595, there are a few things to keep in mind. First, make sure to connect the VCC and GND pins to the correct voltage and ground. Second, use a resistor to limit the current flowing through the LEDs or other components connected to the output pins. Finally, be aware of the maximum clock frequency, which varies depending on the specific model of the IC.

Conclusion

The 74hc595 is a versatile and useful IC for expanding the number of available pins on a microcontroller. By connecting it to your project, you can control multiple components using only a few input pins. With a bit of practice and experimentation, you can use the 74hc595 to create all sorts of interesting electronic projects.