STM32 realizes 74HC595 control

One 、 Preface

         This article is mainly about the realization 74HC595 The simple control function of .

Two 、 summary

（ One ）74HC595 sketch

         74HC595 It's a 8 Bit serial input 、 Displacement buffer with parallel output ： The platform line output is three state output .

         stay SCHCP The rising edge of the input , stay STCP The rising edge of goes into the storage register , If two clocks are connected together , The shift register is always one pulse earlier than the storage register . The shift register has a serial shift input （Ds）, And a serial output （Q7‘）, And an asynchronous low-level reset , The storage register has a parallel 8 Bit , With three state bus output , When enabled OE when （ Low level ）, The data of the storage register is output to the bus .

        74HC595 Support cascading , When more than one 74HC595 When cascaded together , Sending data over a data line will eventually shift to the last 74HC595. Because cascaded data will be squeezed to the next level ic in , So the data sent first is to the last level 74HC595..

        Each direction 74HC595 Send a byte ,74HC595 The first thing to send is the high-order data , That is, the first data received arrives Q7 foot , When we output high data , The highest 8 A pulse will arrive Q7 foot （ The highest bit of the data foot ）, Here's the picture ： 

（ Two ） Pin function

   

（ 3、 ... and ） Truth table

3、 ... and 、 Hardware connection

Four 、 Program routine

1、 The header file

#ifndef _74HC595_H_
#define _74HC595_H_

#include "stm32f10x.h"
#include "io_bit.h"
#include "delay.h"

#define SRCLK PAout(14)
#define RCLK PAout(13)
#define SER PAout(12)

void HC595_Pin_Init(void);
void HC595_Send_Data(u8 data);
void HC595_Send_Byte(u8 dat1,u8 dat2,u8 dat3,u8 dat4);

#endif

2、 Source file

#include "74HC595.h"

void HC595_Pin_Init(void)
{
	 GPIO_InitTypeDef GPIO_InitStructure;

	// Turn on the clock 
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);
	//  Change the mapping of the specified pin  GPIO_Remap_SWJ_Disable SWJ  Completely disabled （JTAG+SW-DP）
	GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable , ENABLE);
	//  Change the mapping of the specified pin  GPIO_Remap_SWJ_JTAGDisable ,JTAG-DP  Ban  + SW-DP  Can make 
	GPIO_PinRemapConfig(GPIO_Remap_SWJ_Disable, ENABLE);

	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12 | GPIO_Pin_13 | GPIO_Pin_14;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA,&GPIO_InitStructure);
	
	GPIO_ResetBits(GPIOA, GPIO_Pin_12 | GPIO_Pin_13 | GPIO_Pin_14);
}


void HC595_Send_Data(u8 data)
{
	u8 i = 0;
	
	for (i = 0; i < 8; i++)
	{
		if (data & 0x80)        // Transmit the high bit first , Judge whether the eighth is 1
			SER = 1;    // If the eighth place is 1, Then with  595 DS The connected pin outputs a high level 
		else                    // Otherwise, the output is low 
			SER = 0;

		SRCLK = 0;
		delay_us(20);
		SRCLK = 1;
		data <<= 1;
	}
}

void HC595_Send_Byte(u8 dat1,u8 dat2,u8 dat3,u8 dat4)
{
	SRCLK = 1;
	RCLK = 1;
	
	HC595_Send_Data(dat1);
	HC595_Send_Data(dat2);
	HC595_Send_Data(dat3);
	HC595_Send_Data(dat4);

	RCLK = 0;
	delay_us(2);
	RCLK = 1;
	delay_us(2);
	RCLK = 0;
	
}

notes ：

        STM32F103C8T6 Master control PA13 and PA14 Default is not GPIO Mouth mode , It needs to be configured as GPIO Mouth mode  

  Links to related materials , You need to download it yourself , thank you ！

         link ：https://pan.baidu.com/s/1Tl-AHndfCAuOs3ykptsV2A 
         Extraction code ：q7ks