ch340连接esp01s

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mob64ca1414c613 2024-12-17 08:46:58

文章标签 ch340连接esp01s 嵌入式数据下降沿上升沿 文章分类 架构后端开发

软件模拟SPI接口程序代码（4种模式）

SPI协议简介

SPI的通信原理很简单，一般主从方式工作，这种模式通常有一个主设备和一个或多个从设备，通常采用的是4根线，它们是MISO（数据输入，针对主机来说）、MOSI（数据输出，针对主机来说）、SCLK（时钟，主机产生）、CS/SS（片选，一般由主机发送或者直接使能，通常为低电平有效）

●SPI接口介绍

SCK：时钟信号，由主设备产生，所以主设备SCK信号为输出模式，从设备的SCK信号为输入模式。

CS：使能信号，由主设备控制从设备，，所以主设备CS信号为输出模式，从设备的CS信号为输入模式。

MOSI：主设备数据输出，从设备数据输入，所以主设备MOSI信号为输出模式，从设备的MOSI信号为输入模式。

MISO：主设备数据输入，从设备数据输出，所以主设备MISO信号为输入模式，从设备的MISO信号为输出模式。

●SPI接口连接图

ch340连接esp01s_下降沿

注意：MOSI和MISO不能交叉连接(可以把主从机理解为一个整体系统，MOSI为系统主机发送从机接收的数据线，MISO为主机接收从机发送的数据线)

●SPI数据传输方向

　SPI作为全双工的的串行通信协议，数据传输时高位在前，低位在后。主机和从机公用由主机产生的SCK信号，所以在每个时钟周期内主机和从机有1bit的数据交换(因为MOSI和MISO数据线上的数据都是在时钟的边沿处被采样)。如下图：

ch340连接esp01s_嵌入式_02

SPI协议规定数据采样是在SCK的上升沿或下降沿时刻(由SPI模式决定，下面会说到)，观察上图，在SCK的边沿处(上升沿或下降沿)，主机会在MISO数据线上采样(接收来从机的数据)，从机会在MOSI数据线上采样(接收来自主机的数据)，所以每个时钟周期中会有一bit的数据交换。

ch340连接esp01s_ch340连接esp01s_03

SPI传输模式

SPI总线传输一共有４种模式，这４种模式分别由时钟极性(CPOL)和时钟相位(CPHA)来定义。

ch340连接esp01s_上升沿_04

ch340连接esp01s_上升沿_05

CPOL：规定了SCK时钟信号空闲状态的电平

CPHA：规定了数据是在SCK时钟的上升沿还是下降沿被采样

----------- ------------------------------------

模式0：CPOL=0，CPHA =0 SCK空闲为低电平，数据在SCK的上升沿被采样(提取数据)

模式1：CPOL=0，CPHA =1 SCK空闲为低电平，数据在SCK的下降沿被采样(提取数据)

模式2：CPOL=1，CPHA =0 SCK空闲为高电平，数据在SCK的下降沿被采样(提取数据)

模式3：CPOL=1，CPHA =1 SCK空闲为高电平，数据在SCK的上升沿被采样(提取数据)

以模式0为例：SCK空闲为低电平，数据在SCK的上升沿被采样(提取数据)，在SCK的下降沿切换数据线的数据。

ch340连接esp01s_嵌入式_06

◐在时钟的第1个上升沿(游标1处)(采样点)

　　MOSI上数据为1，则在此边沿从机采样(提取)数据为1，采样点在MOSI数据线的中间。

　　MISO上数据为0，则在此边沿主机采样(提取)数据为0，采样点在MISO数据线的中间。

◐在时钟的第1个下降沿(游标2处)(切换点)

　　MOSI上数据由1切换为0，，数据在时钟下降沿时切换数据。

　　MISO上数据由0切换为1，，数据在时钟下降沿时切换数据。

◐在时钟的第2~8个上升沿(采样点)，主机在MISO上采样数据，从机在MOSI上采样数据。

◐在时钟的第2~8个下降沿(切换点)，主机在MISO上切换数据，从机在MOSI上切换数据

通过模拟SPI程序来加深理解

使用STM32L4R5ZI MCU进行的测试

初始化代码：

</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">    PA5     ------> SPI1_SCK</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="3"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">    PA6     ------> SPI1_MISO</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="4"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">    PA7     ------> SPI1_MOSI </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="5"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-comment">    */</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="6"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> SPI_SCK_PIN                     GPIO_PIN_5</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="7"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> SPI_SCK_GPIO_PORT               GPIOA</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="8"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> SPI_MOSI_PIN                    GPIO_PIN_7</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="9"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> SPI_MOSI_GPIO_PORT              GPIOA</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="10"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> SPI_MISO_PIN                    GPIO_PIN_6</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="11"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> SPI_MISO_GPIO_PORT              GPIOA</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="12"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> SPI_NSS_PIN                     GPIO_PIN_14</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="13"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> SPI_NSS_GPIO_PORT               GPIOD</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="14"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="15"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="16"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> SPI_SCK_GPIO_CLK_ENABLE()       __HAL_RCC_GPIOA_CLK_ENABLE()</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="17"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> SPI_MISO_GPIO_CLK_ENABLE()      __HAL_RCC_GPIOA_CLK_ENABLE()</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="18"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> SPI_MOSI_GPIO_CLK_ENABLE()      __HAL_RCC_GPIOA_CLK_ENABLE()</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="19"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> SPI_NSS_GPIO_CLK_ENABLE()       __HAL_RCC_GPIOD_CLK_ENABLE()</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="20"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="21"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> MOSI_H  HAL_GPIO_WritePin(SPI_MOSI_GPIO_PORT, SPI_MOSI_PIN, GPIO_PIN_SET)  </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="22"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> MOSI_L  HAL_GPIO_WritePin(SPI_MOSI_GPIO_PORT, SPI_MOSI_PIN, GPIO_PIN_RESET)  </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="23"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> SCK_H   HAL_GPIO_WritePin(SPI_SCK_GPIO_PORT, SPI_SCK_PIN, GPIO_PIN_SET)  </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="24"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> SCK_L   HAL_GPIO_WritePin(SPI_SCK_GPIO_PORT, SPI_SCK_PIN, GPIO_PIN_RESET)  </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="25"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> MISO    HAL_GPIO_ReadPin(SPI_MISO_GPIO_PORT, SPI_MISO_PIN) </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="26"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> NSS_H   HAL_GPIO_WritePin(SPI_NSS_GPIO_PORT, SPI_NSS_PIN, GPIO_PIN_SET)  </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="27"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-meta">#<span class="hljs-meta-keyword">define</span> NSS_L   HAL_GPIO_WritePin(SPI_NSS_GPIO_PORT, SPI_NSS_PIN, GPIO_PIN_RESET) </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="28"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">	·</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="29"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="30"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-function"><span class="hljs-keyword">void</span> <span class="hljs-title">SPI_Init</span><span class="hljs-params">(<span class="hljs-keyword">void</span>)</span></span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="31"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">{  </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="32"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">  <span class="hljs-comment">/*##-1- Enable peripherals and GPIO Clocks #########################*/</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="33"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">  <span class="hljs-comment">/* Enable GPIO TX/RX clock */</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="34"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">  SPI_SCK_GPIO_CLK_ENABLE();</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="35"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">  SPI_MISO_GPIO_CLK_ENABLE();</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="36"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">  SPI_MOSI_GPIO_CLK_ENABLE();</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="37"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">  SPI_NSS_GPIO_CLK_ENABLE();</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="38"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="39"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="40"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">  <span class="hljs-comment">/*##-2- Configure peripheral GPIO #######################*/</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="41"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">  <span class="hljs-comment">/* SPI SCK GPIO pin configuration  */</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="42"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">  GPIO_InitTypeDef GPIO_InitStruct;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="43"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">  </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="44"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">  GPIO_InitStruct.Pin       = SPI_SCK_PIN;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="45"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">  GPIO_InitStruct.Mode      = GPIO_MODE_OUTPUT_PP;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="46"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">  <span class="hljs-comment">//GPIO_InitStruct.Pull      = GPIO_PULLDOWN;</span></div></div></li><li><div ><div  data-line-number="47"></div></div><div ><div >  GPIO_InitStruct.Speed     = GPIO_SPEED_FREQ_VERY_HIGH;</div></div></li><li><div ><div  data-line-number="48"></div></div><div ><div >  HAL_GPIO_Init(SPI_SCK_GPIO_PORT, &GPIO_InitStruct);</div></div></li><li><div ><div  data-line-number="49"></div></div><div ><div >  HAL_GPIO_WritePin(SPI_SCK_GPIO_PORT, SPI_SCK_PIN, GPIO_PIN_SET);</div></div></li><li><div ><div  data-line-number="50"></div></div><div ><div > </div></div></li><li><div ><div  data-line-number="51"></div></div><div ><div >  <span >/* SPI MISO GPIO pin configuration  */</span></div></div></li><li><div ><div  data-line-number="52"></div></div><div ><div >  GPIO_InitStruct.Pin = SPI_MISO_PIN;</div></div></li><li><div ><div  data-line-number="53"></div></div><div ><div >  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;</div></div></li><li><div ><div  data-line-number="54"></div></div><div ><div >  HAL_GPIO_Init(SPI_MISO_GPIO_PORT, &GPIO_InitStruct);</div></div></li><li><div ><div  data-line-number="55"></div></div><div ><div > </div></div></li><li><div ><div  data-line-number="56"></div></div><div ><div >  <span >/* SPI MOSI GPIO pin configuration  */</span></div></div></li><li><div ><div  data-line-number="57"></div></div><div ><div >  GPIO_InitStruct.Pin = SPI_MOSI_PIN;</div></div></li><li><div ><div  data-line-number="58"></div></div><div ><div >  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;</div></div></li><li><div ><div  data-line-number="59"></div></div><div ><div >  HAL_GPIO_Init(SPI_MOSI_GPIO_PORT, &GPIO_InitStruct);</div></div></li><li><div ><div  data-line-number="60"></div></div><div ><div >  HAL_GPIO_WritePin(SPI_MOSI_GPIO_PORT, SPI_MOSI_PIN, GPIO_PIN_SET);</div></div></li><li><div ><div  data-line-number="61"></div></div><div ><div >  </div></div></li><li><div ><div  data-line-number="62"></div></div><div ><div >  GPIO_InitStruct.Pin = SPI_NSS_PIN;</div></div></li><li><div ><div  data-line-number="63"></div></div><div ><div >  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;</div></div></li><li><div ><div  data-line-number="64"></div></div><div ><div >  HAL_GPIO_Init(SPI_NSS_GPIO_PORT, &GPIO_InitStruct);</div></div></li><li><div ><div  data-line-number="65"></div></div><div ><div >  HAL_GPIO_WritePin(SPI_NSS_GPIO_PORT, SPI_NSS_PIN, GPIO_PIN_SET);</div></div></li><li><div ><div  data-line-number="66"></div></div><div ><div >  </div></div></li><li><div ><div  data-line-number="67"></div></div><div ><div >}</div></div></li></ol></code><div  data-title="复制" data-report-click="{"spm":"1001.2101.3001.4259"}" οnclick="hljs.copyCode(event)"></div></pre> 
<p style="margin-left:0cm;"><span style="color:#4d4d4d;">

模拟SPI4种工作模式：

转发自: