stm32单片机个人学习笔记16(SPI通信协议)
前言
本篇文章属于stm32单片机(以下简称单片机)的学习笔记,来源于B站教学视频。下面是这位up主的视频链接。本文为个人学习笔记,只能做参考,细节方面建议观看视频,肯定受益匪浅。
STM32入门教程-2023版 细致讲解 中文字幕_哔哩哔哩_bilibili
一、SPI通信
1.硬件电路规定
2.移位示意图
3.软件时序规定
4.实际通信时序
区别于I2C是对寄存器进行操作,SPI通信的从机会定义一个指令集,起始条件后,主机给从机发一个指令完成相应任务即可
第一个字节为写指令0x02,第二三四个字节为地址,地址高位先行,第五个字节是写入的数据
第一个字节为写指令0x02,第二三四个字节为地址,第五个字节进行交换字节,主机发送一个0xFF或0x00把从机发送的数据交换回来
二、W25Q64
1.简介
2.硬件电路
3.W25Q64框图
把8MB的内存分为128个块(Block),每个块又分为16个扇(Sector),每个扇又分16页(Page) ,每页256B
4.Flash操作注意事项
5.具体细节详见W25Q64的参考手册
三、软件SPI读写W25Q64
1.MySPI.c
#include "stm32f10x.h" // Device header
void MySPI_W_SS(uint8_t BitValue)
{
GPIO_WriteBit(GPIOA, GPIO_Pin_4, (BitAction)BitValue);
}
void MySPI_W_SCK(uint8_t BitValue)
{
GPIO_WriteBit(GPIOA, GPIO_Pin_5, (BitAction)BitValue);
}
void MySPI_W_MOSI(uint8_t BitValue)
{
GPIO_WriteBit(GPIOA, GPIO_Pin_7, (BitAction)BitValue);
}
uint8_t MySPI_R_MISO(void)
{
return GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_6);
}
void MySPI_Init(void)
{
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_7;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
MySPI_W_SS(1);
MySPI_W_SCK(0);
}
void MySPI_Start(void)
{
MySPI_W_SS(0);
}
void MySPI_Stop(void)
{
MySPI_W_SS(1);
}
uint8_t MySPI_SwapByte(uint8_t ByteSend)
{
uint8_t i, ByteReceive = 0x00;
for (i = 0; i < 8;i++)
{
MySPI_W_MOSI(ByteSend & (0x80 >> i));
MySPI_W_SCK(1);
if (MySPI_R_MISO() == 1) {ByteReceive |= (0x80 >> i);}
MySPI_W_SCK(0);
}
return ByteReceive;
}
其中交换字节函数还可写为
uint8_t MySPI_SwapByte(uint8_t ByteSend) { uint8_t i; for (i = 0; i < 8;i++) { MySPI_W_MOSI(ByteSend & 0x80); ByteSend <<= 1; MySPI_W_SCK(1); if (MySPI_R_MISO() == 1) {ByteSend |= 0x01;} MySPI_W_SCK(0); } return ByteSend; }
这样效率更高,但会改变ByteSend的值
2.W25Q64.c
#include "stm32f10x.h" // Device header
#include "MySPI.h"
#include "W25Q64_Ins.h"
void W25Q64_Init(void)
{
MySPI_Init();
}
void W25Q64_ReadID(uint8_t *MID, uint16_t *DID)
{
MySPI_Start();
MySPI_SwapByte(W25Q64_JEDEC_ID);
*MID = MySPI_SwapByte(W25Q64_DUMMY_BYTE);
*DID = MySPI_SwapByte(W25Q64_DUMMY_BYTE);
*DID <<= 8;
*DID |= MySPI_SwapByte(W25Q64_DUMMY_BYTE);
MySPI_Stop();
}
void W25Q64_WriteEnable(void)
{
MySPI_Start();
MySPI_SwapByte(W25Q64_WRITE_ENABLE);
MySPI_Stop();
}
void W25Q64_WaitBusy(void)
{
uint32_t TimeOut = 100000;
MySPI_Start();
MySPI_SwapByte(W25Q64_READ_STATUS_REGISTER_1);
while((MySPI_SwapByte(W25Q64_DUMMY_BYTE) & 0x01) == 0x01)
{
TimeOut--;
if (TimeOut == 0)
{
break;
}
}
MySPI_Stop();
}
void W25Q64_PageProgram(uint32_t Address, uint8_t *DataArray, uint16_t Count)
{
uint16_t i;
W25Q64_WriteEnable();
MySPI_Start();
MySPI_SwapByte(W25Q64_PAGE_PROGRAM);
MySPI_SwapByte(Address >> 16);
MySPI_SwapByte(Address >> 8);
MySPI_SwapByte(Address);
for (i = 0;i < Count;i++)
{
MySPI_SwapByte(DataArray[i]);
}
MySPI_Stop();
W25Q64_WaitBusy();
}
void W25Q64_SectorErase(uint32_t Address)
{
W25Q64_WriteEnable();
MySPI_Start();
MySPI_SwapByte(W25Q64_SECTOR_ERASE_4KB);
MySPI_SwapByte(Address >> 16);
MySPI_SwapByte(Address >> 8);
MySPI_SwapByte(Address);
MySPI_Stop();
W25Q64_WaitBusy();
}
void W25Q64_ReadData(uint32_t Address, uint8_t *DataArray, uint32_t Count)
{
uint32_t i;
MySPI_Start();
MySPI_SwapByte(W25Q64_READ_DATA);
MySPI_SwapByte(Address >> 16);
MySPI_SwapByte(Address >> 8);
MySPI_SwapByte(Address);
for (i = 0;i < Count;i++)
{
DataArray[i] = MySPI_SwapByte(W25Q64_DUMMY_BYTE);
}
MySPI_Stop();
}
3.main.c
#include "stm32f10x.h" // Device header
#include "Delay.h"
#include "OLED.h"
#include "W25Q64.h"
uint8_t MID;
uint16_t DID;
uint8_t ArrayWrite[] = {0xB1, 0xB2, 0xB3, 0xB4};
uint8_t ArrayRead[4];
int main(void)
{
OLED_Init();
W25Q64_Init();
OLED_ShowString(1, 1, "MID: DID:");
OLED_ShowString(2, 1, "W:");
OLED_ShowString(3, 1, "R:");
W25Q64_ReadID(&MID, &DID);
OLED_ShowHexNum(1, 5, MID, 2);
OLED_ShowHexNum(1, 12, DID, 4);
W25Q64_SectorErase(0x000000);
W25Q64_PageProgram(0x000000, ArrayWrite, 4);
W25Q64_ReadData(0x000000, ArrayRead, 4);
OLED_ShowHexNum(2, 3, ArrayWrite[0], 2);
OLED_ShowHexNum(2, 6, ArrayWrite[1], 2);
OLED_ShowHexNum(2, 9, ArrayWrite[2], 2);
OLED_ShowHexNum(2, 12, ArrayWrite[3], 2);
OLED_ShowHexNum(3, 3, ArrayRead[0], 2);
OLED_ShowHexNum(3, 6, ArrayRead[1], 2);
OLED_ShowHexNum(3, 9, ArrayRead[2], 2);
OLED_ShowHexNum(3, 12, ArrayRead[3], 2);
while (1)
{
}
}
四、硬件SPI读写W25Q64
1.SPI通信外设
2.SPI框图
3.SPI基本结构
4.主模式全双工连续传输(较为复杂,性能好)
5.非连续传输(较为简单,性能差一点)
6.代码部分
只需更改MySPI.c部分的内容即可
配置好硬件SPI
#include "stm32f10x.h" // Device header
void MySPI_W_SS(uint8_t BitValue)
{
GPIO_WriteBit(GPIOA, GPIO_Pin_4, (BitAction)BitValue);
}
void MySPI_Init(void)
{
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_7;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
SPI_InitTypeDef SPI_InitStructure;
SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_128;
SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;
SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
SPI_InitStructure.SPI_CRCPolynomial = 7;
SPI_Init(SPI1, &SPI_InitStructure);
SPI_Cmd(SPI1, ENABLE);
MySPI_W_SS(1);
}
void MySPI_Start(void)
{
MySPI_W_SS(0);
}
void MySPI_Stop(void)
{
MySPI_W_SS(1);
}
uint8_t MySPI_SwapByte(uint8_t ByteSend)
{
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) != SET);
SPI_I2S_SendData(SPI1, ByteSend);
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) != SET);
return SPI_I2S_ReceiveData(SPI1);
}