目錄
前言
技術實現?
原理圖
連線圖
代碼實現?
內容要點
PWM基本結構
開啟外設時鐘
配置GPIO端口
配置時基單元
?初始化輸出比較單元
輸出比較通道重映射?
輸入捕獲功能初始化
?計算捕獲PWM的頻率
實驗結果
問題記錄
前言
?IC(Input Capture)輸入捕獲,?輸入捕獲模式下,當通道輸入引腳出現指定電平跳變時,當前CNT的值將被鎖存到CCR中,可用于測量PWM波形的頻率、占空比、脈沖間隔、電平持續時間等參數,每個高級定時器和通用定時器都擁有4個輸入捕獲通道,可配置為PWMI模式,同時測量頻率和占空比,可配合主從觸發模式,實現硬件全自動測量。
技術實現?
原理圖
無
連線圖
代碼實現?
main.c
#include "stm32f10x.h" // Device header
#include "Delay.h" //延時函數
#include "OLED.h"
#include "PWM.h"
#include "IC.h"int main(void)
{OLED_Init();PWM_Init();IC_Init();/**@note也可以在PWM_Init中將結構體TIM_OCInitStruct成員TIM_Prescaler設置為720-1,** 將成員TIM_Pulse的值設置為50代替此處兩個函數調用**/PWM_SetCompler(720-1); //Freq = 72MHz / (PSC + 1) / 100PWM_SetComparel(50); //Duty = CCR / 100OLED_ShowString(1,1,"Freq:00000Hz");while(1){OLED_ShowNum(1,6,IC_GetFreq(),5);}
}
PWM.h?
#ifndef __PWM_H__
#define __PWM_H__#include "stm32f10x.h" // Device headervoid PWM_Init(void);
void PWM_SetComparel(uint16_t Compare);
void PWM_SetCompler(uint16_t Prescaler);#endif
PWM.c
#include "PWM.h"/*** @brief PWM初始化函數* @param None* @retval None* @note 輸出頻率為1kHz,占空比為50%,分辨率為1%的PWM波形
**/
void PWM_Init(void)
{/*開啟時鐘*/RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE); //開啟TIM2時鐘RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE); //開啟GPIOA時鐘
// RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE); //開啟AFIO時鐘
//
// /*
// 引腳重映射
// */
// GPIO_PinRemapConfig(GPIO_PartialRemap1_TIM2,ENABLE); //將TIM2的CH1從PA0重映射到PA15
// /*
// 解除引腳復用
// */
// GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable,ENABLE); //PA15引腳默認作為JTD1功能使用,此處解除AFIO的JTAG復用/*配置端口*/GPIO_InitTypeDef GPIO_InitStruct; //定義結構體GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0; //選擇PA0 //重映射到GPIO_Pin_15GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP; //復用推挽輸出,將引腳的控制權交給片上外設GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA,&GPIO_InitStruct);/*選擇TIM時鐘*/TIM_InternalClockConfig(TIM2);/*配置時基單元*/TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct; //定義一個TIM_TimeBaseInitTypeDef類型的結構體用于初始化時基單元TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1; //設置時鐘分頻模式為不分TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up; //計數方式設置為向上計數模式/*輸出的PWM波形的頻率為1kHz,分辨率為1%PWM頻率: Freq = CK_PSC / (PSC + 1) / (ARR + 1)PWM占空比: Duty = CCR / (ARR + 1)PWM分辨率: Reso = 1 / (ARR + 1)*/TIM_TimeBaseInitStruct.TIM_Period = 100-1; //ARR,自動加載重裝寄存器,要寫入自動重裝值TIM_TimeBaseInitStruct.TIM_Prescaler = 720-1; //PSC,預分頻器的分頻值TIM_TimeBaseInitStruct.TIM_RepetitionCounter = 0; //重復計數,只有高級定時器才會使用,通用定時器用不到TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStruct); //初始化時基單元/*初始化輸出比較單元*/TIM_OCInitTypeDef TIM_OCInitStruct; //定義一個TIM_OCInitTypeDef類型的結構體用以輸出比較單元初始化TIM_OCStructInit(&TIM_OCInitStruct); //給每個結構體成員賦初始值,防止因未使用到的結構體成員未初始化而導致程序出現錯誤TIM_OCInitStruct.TIM_OCMode = TIM_OCMode_PWM1; //選擇PWM模式1TIM_OCInitStruct.TIM_OCPolarity = TIM_OCPolarity_High; //OC1有效電平為高電平TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable; //輸出比較使能/*輸出PWM的波形占空比PWM占空比: Duty = CCR / (ARR + 1)*/TIM_OCInitStruct.TIM_Pulse = 0; //CCR,捕獲/比較器,本工程中有封裝的函數用于改變占空比,此處先設置為0TIM_OC1Init(TIM2,&TIM_OCInitStruct);TIM_Cmd(TIM2,ENABLE); //啟動TIM2
}/*** @brief 指定CCR寄存器的值改變PWM Duty* @param None* @retval None* @note None
**/
void PWM_SetComparel(uint16_t Compare)
{TIM_SetCompare1(TIM2,Compare);
}/*** @brief 修改PSC寄存器的值* @param None* @retval None* @note None
**/
void PWM_SetCompler(uint16_t Prescaler)
{TIM_PrescalerConfig(TIM2,Prescaler,TIM_PSCReloadMode_Immediate); //配置預分頻器的值
}
?IC.h
#ifndef __IC_H__
#define __IC_H__#include "stm32f10x.h" // Device headervoid IC_Init(void);
uint32_t IC_GetFreq(void);#endif
IC.c?
#include "IC.h"/*** @brief IC初始化* @param None* @retval None* @note 使用TIM3進行輸入捕獲
**/
void IC_Init(void)
{/*開啟時鐘*/RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE); //開啟TIM2時鐘RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE); //開啟GPIOA時鐘GPIO_InitTypeDef GPIO_InitStruct; //定義結構體GPIO_InitStruct.GPIO_Pin = GPIO_Pin_6; //選擇PA0 GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IPU; //選擇上拉輸入模式GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA,&GPIO_InitStruct);/*選擇TIM時鐘*/TIM_InternalClockConfig(TIM3);/*配置時基單元*/TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct; //定義一個TIM_TimeBaseInitTypeDef類型的結構體用于初始化時基單元TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1; //設置時鐘分頻模式為不分TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up; //計數方式設置為向上計數模式/*輸出的PWM波形的頻率為1kHz,分辨率為1%PWM頻率: Freq = CK_PSC / (PSC + 1) / (ARR + 1)PWM占空比: Duty = CCR / (ARR + 1)PWM分辨率: Reso = 1 / (ARR + 1)*/TIM_TimeBaseInitStruct.TIM_Period = 65536-1; //ARR,自動加載重裝寄存器,要寫入自動重裝值,將ARR的值設為最大值,防止溢出TIM_TimeBaseInitStruct.TIM_Prescaler = 72-1; //PSC,預分頻器的分頻值TIM_TimeBaseInitStruct.TIM_RepetitionCounter = 0; //重復計數,只有高級定時器才會使用,通用定時器用不到TIM_TimeBaseInit(TIM3,&TIM_TimeBaseInitStruct); //初始化時基單元/*初始化輸入捕獲單元*/TIM_ICInitTypeDef TIM_ICInitStruct; //定義結構體用于初始化輸入捕獲單元TIM_ICInitStruct.TIM_Channel = TIM_Channel_1; //選擇TIM3輸入捕獲通道1TIM_ICInitStruct.TIM_ICFilter = 0xF; //輸入濾波,濾除噪音,使信號更平滑,并不會改變輸入信號的頻率TIM_ICInitStruct.TIM_ICPolarity = TIM_ICPolarity_Rising; //選擇上升沿觸發 TIM_ICInitStruct.TIM_ICPrescaler = TIM_ICPSC_DIV1; //不分頻TIM_ICInitStruct.TIM_ICSelection = TIM_ICSelection_DirectTI;TIM_ICInit(TIM3,&TIM_ICInitStruct);/*觸發源選擇*/TIM_SelectInputTrigger(TIM3,TIM_TS_TI1FP1); //觸發源選擇濾波定時器輸入1/*選擇從模式*/TIM_SelectSlaveMode(TIM3,TIM_SlaveMode_Reset); //上升沿初始化計數器并觸發寄存器更新/*啟動定時器*/TIM_Cmd(TIM3,ENABLE);
}/*** @brief 計算頻率值* @param None* @retval 輸出PWM的頻率* @note 讀取CCR的值計算頻率值
**/
uint32_t IC_GetFreq(void)
{return 1000000/(TIM_GetCapture1(TIM3)+1); //加1使為了消除測量的誤差,使輸出的頻率值恰好為1000Hz
}
?OLED.h
#ifndef __OLED_H
#define __OLED_Hvoid OLED_Init(void);
void OLED_Clear(void);
void OLED_ShowChar(uint8_t Line, uint8_t Column, char Char);
void OLED_ShowString(uint8_t Line, uint8_t Column, char *String);
void OLED_ShowNum(uint8_t Line, uint8_t Column, uint32_t Number, uint8_t Length);
void OLED_ShowSignedNum(uint8_t Line, uint8_t Column, int32_t Number, uint8_t Length);
void OLED_ShowHexNum(uint8_t Line, uint8_t Column, uint32_t Number, uint8_t Length);
void OLED_ShowBinNum(uint8_t Line, uint8_t Column, uint32_t Number, uint8_t Length);#endif
?OLED.c
#include "stm32f10x.h"
#include "OLED_Font.h"/*引腳配置*/
#define OLED_W_SCL(x) GPIO_WriteBit(GPIOB, GPIO_Pin_8, (BitAction)(x)) //可更改引腳配置
#define OLED_W_SDA(x) GPIO_WriteBit(GPIOB, GPIO_Pin_9, (BitAction)(x)) //更改引腳時,改變參數GPIOx,GPIO_Pin_x/*引腳初始化*/
void OLED_I2C_Init(void)
{RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);GPIO_InitTypeDef GPIO_InitStructure;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD; //將引腳的輸出模式設置為開漏輸出GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;//更改引腳時,改變參數GPIOx,GPIO_Pin_xGPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;GPIO_Init(GPIOB, &GPIO_InitStructure);//更改引腳時,改變參數GPIOx,GPIO_Pin_xGPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;GPIO_Init(GPIOB, &GPIO_InitStructure);OLED_W_SCL(1);OLED_W_SDA(1);
}/*** @brief I2C開始* @param 無* @retval 無*/
void OLED_I2C_Start(void)
{OLED_W_SDA(1);OLED_W_SCL(1);OLED_W_SDA(0);OLED_W_SCL(0);
}/*** @brief I2C停止* @param 無* @retval 無*/
void OLED_I2C_Stop(void)
{OLED_W_SDA(0);OLED_W_SCL(1);OLED_W_SDA(1);
}/*** @brief I2C發送一個字節* @param Byte 要發送的一個字節* @retval 無*/
void OLED_I2C_SendByte(uint8_t Byte)
{uint8_t i;for (i = 0; i < 8; i++){OLED_W_SDA(!!(Byte & (0x80 >> i)));OLED_W_SCL(1);OLED_W_SCL(0);}OLED_W_SCL(1); //額外的一個時鐘,不處理應答信號OLED_W_SCL(0);
}/*** @brief OLED寫命令* @param Command 要寫入的命令* @retval 無*/
void OLED_WriteCommand(uint8_t Command)
{OLED_I2C_Start();OLED_I2C_SendByte(0x78); //從機地址OLED_I2C_SendByte(0x00); //寫命令OLED_I2C_SendByte(Command); OLED_I2C_Stop();
}/*** @brief OLED寫數據* @param Data 要寫入的數據* @retval 無*/
void OLED_WriteData(uint8_t Data)
{OLED_I2C_Start();OLED_I2C_SendByte(0x78); //從機地址OLED_I2C_SendByte(0x40); //寫數據OLED_I2C_SendByte(Data);OLED_I2C_Stop();
}/*** @brief OLED設置光標位置* @param Y 以左上角為原點,向下方向的坐標,范圍:0~7* @param X 以左上角為原點,向右方向的坐標,范圍:0~127* @retval 無*/
void OLED_SetCursor(uint8_t Y, uint8_t X)
{OLED_WriteCommand(0xB0 | Y); //設置Y位置OLED_WriteCommand(0x10 | ((X & 0xF0) >> 4)); //設置X位置高4位OLED_WriteCommand(0x00 | (X & 0x0F)); //設置X位置低4位
}/*** @brief OLED清屏* @param 無* @retval 無*/
void OLED_Clear(void)
{ uint8_t i, j;for (j = 0; j < 8; j++){OLED_SetCursor(j, 0);for(i = 0; i < 128; i++){OLED_WriteData(0x00);}}
}/*** @brief OLED顯示一個字符* @param Line 行位置,范圍:1~4* @param Column 列位置,范圍:1~16* @param Char 要顯示的一個字符,范圍:ASCII可見字符* @retval 無*/
void OLED_ShowChar(uint8_t Line, uint8_t Column, char Char)
{ uint8_t i;OLED_SetCursor((Line - 1) * 2, (Column - 1) * 8); //設置光標位置在上半部分for (i = 0; i < 8; i++){OLED_WriteData(OLED_F8x16[Char - ' '][i]); //顯示上半部分內容}OLED_SetCursor((Line - 1) * 2 + 1, (Column - 1) * 8); //設置光標位置在下半部分for (i = 0; i < 8; i++){OLED_WriteData(OLED_F8x16[Char - ' '][i + 8]); //顯示下半部分內容}
}/*** @brief OLED顯示字符串* @param Line 起始行位置,范圍:1~4* @param Column 起始列位置,范圍:1~16* @param String 要顯示的字符串,范圍:ASCII可見字符* @retval 無*/
void OLED_ShowString(uint8_t Line, uint8_t Column, char *String)
{uint8_t i;for (i = 0; String[i] != '\0'; i++){OLED_ShowChar(Line, Column + i, String[i]);}
}/*** @brief OLED次方函數* @retval 返回值等于X的Y次方*/
uint32_t OLED_Pow(uint32_t X, uint32_t Y)
{uint32_t Result = 1;while (Y--){Result *= X;}return Result;
}/*** @brief OLED顯示數字(十進制,正數)* @param Line 起始行位置,范圍:1~4* @param Column 起始列位置,范圍:1~16* @param Number 要顯示的數字,范圍:0~4294967295* @param Length 要顯示數字的長度,范圍:1~10* @retval 無*/
void OLED_ShowNum(uint8_t Line, uint8_t Column, uint32_t Number, uint8_t Length)
{uint8_t i;for (i = 0; i < Length; i++) {OLED_ShowChar(Line, Column + i, Number / OLED_Pow(10, Length - i - 1) % 10 + '0');}
}/*** @brief OLED顯示數字(十進制,帶符號數)* @param Line 起始行位置,范圍:1~4* @param Column 起始列位置,范圍:1~16* @param Number 要顯示的數字,范圍:-2147483648~2147483647* @param Length 要顯示數字的長度,范圍:1~10* @retval 無*/
void OLED_ShowSignedNum(uint8_t Line, uint8_t Column, int32_t Number, uint8_t Length)
{uint8_t i;uint32_t Number1;if (Number >= 0){OLED_ShowChar(Line, Column, '+');Number1 = Number;}else{OLED_ShowChar(Line, Column, '-');Number1 = -Number;}for (i = 0; i < Length; i++) {OLED_ShowChar(Line, Column + i + 1, Number1 / OLED_Pow(10, Length - i - 1) % 10 + '0');}
}/*** @brief OLED顯示數字(十六進制,正數)* @param Line 起始行位置,范圍:1~4* @param Column 起始列位置,范圍:1~16* @param Number 要顯示的數字,范圍:0~0xFFFFFFFF* @param Length 要顯示數字的長度,范圍:1~8* @retval 無*/
void OLED_ShowHexNum(uint8_t Line, uint8_t Column, uint32_t Number, uint8_t Length)
{uint8_t i, SingleNumber;for (i = 0; i < Length; i++) {SingleNumber = Number / OLED_Pow(16, Length - i - 1) % 16;if (SingleNumber < 10){OLED_ShowChar(Line, Column + i, SingleNumber + '0');}else{OLED_ShowChar(Line, Column + i, SingleNumber - 10 + 'A');}}
}/*** @brief OLED顯示數字(二進制,正數)* @param Line 起始行位置,范圍:1~4* @param Column 起始列位置,范圍:1~16* @param Number 要顯示的數字,范圍:0~1111 1111 1111 1111* @param Length 要顯示數字的長度,范圍:1~16* @retval 無*/
void OLED_ShowBinNum(uint8_t Line, uint8_t Column, uint32_t Number, uint8_t Length)
{uint8_t i;for (i = 0; i < Length; i++) {OLED_ShowChar(Line, Column + i, Number / OLED_Pow(2, Length - i - 1) % 2 + '0');}
}/*** @brief OLED初始化* @param 無* @retval 無*/
void OLED_Init(void)
{uint32_t i, j;for (i = 0; i < 1000; i++) //上電延時{for (j = 0; j < 1000; j++);}OLED_I2C_Init(); //端口初始化OLED_WriteCommand(0xAE); //關閉顯示OLED_WriteCommand(0xD5); //設置顯示時鐘分頻比/振蕩器頻率OLED_WriteCommand(0x80);OLED_WriteCommand(0xA8); //設置多路復用率OLED_WriteCommand(0x3F);OLED_WriteCommand(0xD3); //設置顯示偏移OLED_WriteCommand(0x00);OLED_WriteCommand(0x40); //設置顯示開始行OLED_WriteCommand(0xA1); //設置左右方向,0xA1正常 0xA0左右反置OLED_WriteCommand(0xC8); //設置上下方向,0xC8正常 0xC0上下反置OLED_WriteCommand(0xDA); //設置COM引腳硬件配置OLED_WriteCommand(0x12);OLED_WriteCommand(0x81); //設置對比度控制OLED_WriteCommand(0xCF);OLED_WriteCommand(0xD9); //設置預充電周期OLED_WriteCommand(0xF1);OLED_WriteCommand(0xDB); //設置VCOMH取消選擇級別OLED_WriteCommand(0x30);OLED_WriteCommand(0xA4); //設置整個顯示打開/關閉OLED_WriteCommand(0xA6); //設置正常/倒轉顯示OLED_WriteCommand(0x8D); //設置充電泵OLED_WriteCommand(0x14);OLED_WriteCommand(0xAF); //開啟顯示OLED_Clear(); //OLED清屏
}
?OLED_Font.h
#ifndef __OLED_FONT_H
#define __OLED_FONT_H/*OLED字模庫,寬8像素,高16像素*/
const uint8_t OLED_F8x16[][16]=
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,// 00x00,0x00,0x00,0xF8,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x33,0x30,0x00,0x00,0x00,//! 10x00,0x10,0x0C,0x06,0x10,0x0C,0x06,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//" 20x40,0xC0,0x78,0x40,0xC0,0x78,0x40,0x00,0x04,0x3F,0x04,0x04,0x3F,0x04,0x04,0x00,//# 30x00,0x70,0x88,0xFC,0x08,0x30,0x00,0x00,0x00,0x18,0x20,0xFF,0x21,0x1E,0x00,0x00,//$ 40xF0,0x08,0xF0,0x00,0xE0,0x18,0x00,0x00,0x00,0x21,0x1C,0x03,0x1E,0x21,0x1E,0x00,//% 50x00,0xF0,0x08,0x88,0x70,0x00,0x00,0x00,0x1E,0x21,0x23,0x24,0x19,0x27,0x21,0x10,//& 60x10,0x16,0x0E,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//' 70x00,0x00,0x00,0xE0,0x18,0x04,0x02,0x00,0x00,0x00,0x00,0x07,0x18,0x20,0x40,0x00,//( 80x00,0x02,0x04,0x18,0xE0,0x00,0x00,0x00,0x00,0x40,0x20,0x18,0x07,0x00,0x00,0x00,//) 90x40,0x40,0x80,0xF0,0x80,0x40,0x40,0x00,0x02,0x02,0x01,0x0F,0x01,0x02,0x02,0x00,//* 100x00,0x00,0x00,0xF0,0x00,0x00,0x00,0x00,0x01,0x01,0x01,0x1F,0x01,0x01,0x01,0x00,//+ 110x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x80,0xB0,0x70,0x00,0x00,0x00,0x00,0x00,//, 120x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x01,0x01,0x01,0x01,0x01,0x01,//- 130x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x30,0x30,0x00,0x00,0x00,0x00,0x00,//. 140x00,0x00,0x00,0x00,0x80,0x60,0x18,0x04,0x00,0x60,0x18,0x06,0x01,0x00,0x00,0x00,/// 150x00,0xE0,0x10,0x08,0x08,0x10,0xE0,0x00,0x00,0x0F,0x10,0x20,0x20,0x10,0x0F,0x00,//0 160x00,0x10,0x10,0xF8,0x00,0x00,0x00,0x00,0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00,//1 170x00,0x70,0x08,0x08,0x08,0x88,0x70,0x00,0x00,0x30,0x28,0x24,0x22,0x21,0x30,0x00,//2 180x00,0x30,0x08,0x88,0x88,0x48,0x30,0x00,0x00,0x18,0x20,0x20,0x20,0x11,0x0E,0x00,//3 190x00,0x00,0xC0,0x20,0x10,0xF8,0x00,0x00,0x00,0x07,0x04,0x24,0x24,0x3F,0x24,0x00,//4 200x00,0xF8,0x08,0x88,0x88,0x08,0x08,0x00,0x00,0x19,0x21,0x20,0x20,0x11,0x0E,0x00,//5 210x00,0xE0,0x10,0x88,0x88,0x18,0x00,0x00,0x00,0x0F,0x11,0x20,0x20,0x11,0x0E,0x00,//6 220x00,0x38,0x08,0x08,0xC8,0x38,0x08,0x00,0x00,0x00,0x00,0x3F,0x00,0x00,0x00,0x00,//7 230x00,0x70,0x88,0x08,0x08,0x88,0x70,0x00,0x00,0x1C,0x22,0x21,0x21,0x22,0x1C,0x00,//8 240x00,0xE0,0x10,0x08,0x08,0x10,0xE0,0x00,0x00,0x00,0x31,0x22,0x22,0x11,0x0F,0x00,//9 250x00,0x00,0x00,0xC0,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x30,0x30,0x00,0x00,0x00,//: 260x00,0x00,0x00,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x80,0x60,0x00,0x00,0x00,0x00,//; 270x00,0x00,0x80,0x40,0x20,0x10,0x08,0x00,0x00,0x01,0x02,0x04,0x08,0x10,0x20,0x00,//< 280x40,0x40,0x40,0x40,0x40,0x40,0x40,0x00,0x04,0x04,0x04,0x04,0x04,0x04,0x04,0x00,//= 290x00,0x08,0x10,0x20,0x40,0x80,0x00,0x00,0x00,0x20,0x10,0x08,0x04,0x02,0x01,0x00,//> 300x00,0x70,0x48,0x08,0x08,0x08,0xF0,0x00,0x00,0x00,0x00,0x30,0x36,0x01,0x00,0x00,//? 310xC0,0x30,0xC8,0x28,0xE8,0x10,0xE0,0x00,0x07,0x18,0x27,0x24,0x23,0x14,0x0B,0x00,//@ 320x00,0x00,0xC0,0x38,0xE0,0x00,0x00,0x00,0x20,0x3C,0x23,0x02,0x02,0x27,0x38,0x20,//A 330x08,0xF8,0x88,0x88,0x88,0x70,0x00,0x00,0x20,0x3F,0x20,0x20,0x20,0x11,0x0E,0x00,//B 340xC0,0x30,0x08,0x08,0x08,0x08,0x38,0x00,0x07,0x18,0x20,0x20,0x20,0x10,0x08,0x00,//C 350x08,0xF8,0x08,0x08,0x08,0x10,0xE0,0x00,0x20,0x3F,0x20,0x20,0x20,0x10,0x0F,0x00,//D 360x08,0xF8,0x88,0x88,0xE8,0x08,0x10,0x00,0x20,0x3F,0x20,0x20,0x23,0x20,0x18,0x00,//E 370x08,0xF8,0x88,0x88,0xE8,0x08,0x10,0x00,0x20,0x3F,0x20,0x00,0x03,0x00,0x00,0x00,//F 380xC0,0x30,0x08,0x08,0x08,0x38,0x00,0x00,0x07,0x18,0x20,0x20,0x22,0x1E,0x02,0x00,//G 390x08,0xF8,0x08,0x00,0x00,0x08,0xF8,0x08,0x20,0x3F,0x21,0x01,0x01,0x21,0x3F,0x20,//H 400x00,0x08,0x08,0xF8,0x08,0x08,0x00,0x00,0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00,//I 410x00,0x00,0x08,0x08,0xF8,0x08,0x08,0x00,0xC0,0x80,0x80,0x80,0x7F,0x00,0x00,0x00,//J 420x08,0xF8,0x88,0xC0,0x28,0x18,0x08,0x00,0x20,0x3F,0x20,0x01,0x26,0x38,0x20,0x00,//K 430x08,0xF8,0x08,0x00,0x00,0x00,0x00,0x00,0x20,0x3F,0x20,0x20,0x20,0x20,0x30,0x00,//L 440x08,0xF8,0xF8,0x00,0xF8,0xF8,0x08,0x00,0x20,0x3F,0x00,0x3F,0x00,0x3F,0x20,0x00,//M 450x08,0xF8,0x30,0xC0,0x00,0x08,0xF8,0x08,0x20,0x3F,0x20,0x00,0x07,0x18,0x3F,0x00,//N 460xE0,0x10,0x08,0x08,0x08,0x10,0xE0,0x00,0x0F,0x10,0x20,0x20,0x20,0x10,0x0F,0x00,//O 470x08,0xF8,0x08,0x08,0x08,0x08,0xF0,0x00,0x20,0x3F,0x21,0x01,0x01,0x01,0x00,0x00,//P 480xE0,0x10,0x08,0x08,0x08,0x10,0xE0,0x00,0x0F,0x18,0x24,0x24,0x38,0x50,0x4F,0x00,//Q 490x08,0xF8,0x88,0x88,0x88,0x88,0x70,0x00,0x20,0x3F,0x20,0x00,0x03,0x0C,0x30,0x20,//R 500x00,0x70,0x88,0x08,0x08,0x08,0x38,0x00,0x00,0x38,0x20,0x21,0x21,0x22,0x1C,0x00,//S 510x18,0x08,0x08,0xF8,0x08,0x08,0x18,0x00,0x00,0x00,0x20,0x3F,0x20,0x00,0x00,0x00,//T 520x08,0xF8,0x08,0x00,0x00,0x08,0xF8,0x08,0x00,0x1F,0x20,0x20,0x20,0x20,0x1F,0x00,//U 530x08,0x78,0x88,0x00,0x00,0xC8,0x38,0x08,0x00,0x00,0x07,0x38,0x0E,0x01,0x00,0x00,//V 540xF8,0x08,0x00,0xF8,0x00,0x08,0xF8,0x00,0x03,0x3C,0x07,0x00,0x07,0x3C,0x03,0x00,//W 550x08,0x18,0x68,0x80,0x80,0x68,0x18,0x08,0x20,0x30,0x2C,0x03,0x03,0x2C,0x30,0x20,//X 560x08,0x38,0xC8,0x00,0xC8,0x38,0x08,0x00,0x00,0x00,0x20,0x3F,0x20,0x00,0x00,0x00,//Y 570x10,0x08,0x08,0x08,0xC8,0x38,0x08,0x00,0x20,0x38,0x26,0x21,0x20,0x20,0x18,0x00,//Z 580x00,0x00,0x00,0xFE,0x02,0x02,0x02,0x00,0x00,0x00,0x00,0x7F,0x40,0x40,0x40,0x00,//[ 590x00,0x0C,0x30,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x06,0x38,0xC0,0x00,//\ 600x00,0x02,0x02,0x02,0xFE,0x00,0x00,0x00,0x00,0x40,0x40,0x40,0x7F,0x00,0x00,0x00,//] 610x00,0x00,0x04,0x02,0x02,0x02,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//^ 620x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,//_ 630x00,0x02,0x02,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//` 640x00,0x00,0x80,0x80,0x80,0x80,0x00,0x00,0x00,0x19,0x24,0x22,0x22,0x22,0x3F,0x20,//a 650x08,0xF8,0x00,0x80,0x80,0x00,0x00,0x00,0x00,0x3F,0x11,0x20,0x20,0x11,0x0E,0x00,//b 660x00,0x00,0x00,0x80,0x80,0x80,0x00,0x00,0x00,0x0E,0x11,0x20,0x20,0x20,0x11,0x00,//c 670x00,0x00,0x00,0x80,0x80,0x88,0xF8,0x00,0x00,0x0E,0x11,0x20,0x20,0x10,0x3F,0x20,//d 680x00,0x00,0x80,0x80,0x80,0x80,0x00,0x00,0x00,0x1F,0x22,0x22,0x22,0x22,0x13,0x00,//e 690x00,0x80,0x80,0xF0,0x88,0x88,0x88,0x18,0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00,//f 700x00,0x00,0x80,0x80,0x80,0x80,0x80,0x00,0x00,0x6B,0x94,0x94,0x94,0x93,0x60,0x00,//g 710x08,0xF8,0x00,0x80,0x80,0x80,0x00,0x00,0x20,0x3F,0x21,0x00,0x00,0x20,0x3F,0x20,//h 720x00,0x80,0x98,0x98,0x00,0x00,0x00,0x00,0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00,//i 730x00,0x00,0x00,0x80,0x98,0x98,0x00,0x00,0x00,0xC0,0x80,0x80,0x80,0x7F,0x00,0x00,//j 740x08,0xF8,0x00,0x00,0x80,0x80,0x80,0x00,0x20,0x3F,0x24,0x02,0x2D,0x30,0x20,0x00,//k 750x00,0x08,0x08,0xF8,0x00,0x00,0x00,0x00,0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00,//l 760x80,0x80,0x80,0x80,0x80,0x80,0x80,0x00,0x20,0x3F,0x20,0x00,0x3F,0x20,0x00,0x3F,//m 770x80,0x80,0x00,0x80,0x80,0x80,0x00,0x00,0x20,0x3F,0x21,0x00,0x00,0x20,0x3F,0x20,//n 780x00,0x00,0x80,0x80,0x80,0x80,0x00,0x00,0x00,0x1F,0x20,0x20,0x20,0x20,0x1F,0x00,//o 790x80,0x80,0x00,0x80,0x80,0x00,0x00,0x00,0x80,0xFF,0xA1,0x20,0x20,0x11,0x0E,0x00,//p 800x00,0x00,0x00,0x80,0x80,0x80,0x80,0x00,0x00,0x0E,0x11,0x20,0x20,0xA0,0xFF,0x80,//q 810x80,0x80,0x80,0x00,0x80,0x80,0x80,0x00,0x20,0x20,0x3F,0x21,0x20,0x00,0x01,0x00,//r 820x00,0x00,0x80,0x80,0x80,0x80,0x80,0x00,0x00,0x33,0x24,0x24,0x24,0x24,0x19,0x00,//s 830x00,0x80,0x80,0xE0,0x80,0x80,0x00,0x00,0x00,0x00,0x00,0x1F,0x20,0x20,0x00,0x00,//t 840x80,0x80,0x00,0x00,0x00,0x80,0x80,0x00,0x00,0x1F,0x20,0x20,0x20,0x10,0x3F,0x20,//u 850x80,0x80,0x80,0x00,0x00,0x80,0x80,0x80,0x00,0x01,0x0E,0x30,0x08,0x06,0x01,0x00,//v 860x80,0x80,0x00,0x80,0x00,0x80,0x80,0x80,0x0F,0x30,0x0C,0x03,0x0C,0x30,0x0F,0x00,//w 870x00,0x80,0x80,0x00,0x80,0x80,0x80,0x00,0x00,0x20,0x31,0x2E,0x0E,0x31,0x20,0x00,//x 880x80,0x80,0x80,0x00,0x00,0x80,0x80,0x80,0x80,0x81,0x8E,0x70,0x18,0x06,0x01,0x00,//y 890x00,0x80,0x80,0x80,0x80,0x80,0x80,0x00,0x00,0x21,0x30,0x2C,0x22,0x21,0x30,0x00,//z 900x00,0x00,0x00,0x00,0x80,0x7C,0x02,0x02,0x00,0x00,0x00,0x00,0x00,0x3F,0x40,0x40,//{ 910x00,0x00,0x00,0x00,0xFF,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFF,0x00,0x00,0x00,//| 920x00,0x02,0x02,0x7C,0x80,0x00,0x00,0x00,0x00,0x40,0x40,0x3F,0x00,0x00,0x00,0x00,//} 930x00,0x06,0x01,0x01,0x02,0x02,0x04,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//~ 94
};#endif
內容要點
PWM基本結構
開啟外設時鐘
/*開啟時鐘*/RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE); //開啟TIM2時鐘
本實驗使用TIM2輸出調制PWM波來驅動LED呼吸燈,TIM2屬于APB1外設,調用RCC_APB1PeriphClockCmd()函數來開啟APB1外設時鐘。
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE); //開啟GPIOA時鐘
根據STM32引腳的定義,PA0的默認復用功能為TIM2的輸出比較通道之一TIM2_CH1,GPIOA隸屬于APB2外設,調用RCC_APB2PeriphClockCmd()函數開啟APB2外設時鐘。
配置GPIO端口
/*配置端口*/GPIO_InitTypeDef GPIO_InitStruct; //定義結構體GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0; //選擇PA0 //重映射到GPIO_Pin_15GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP; //復用推挽輸出,將引腳的控制權交給片上外設GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA,&GPIO_InitStruct);
GPIO初始化中,初始化結構體GPIO_InitStruct結構體成員,將GPIO引腳設置為PA0 Pin,將GPIO模式設置為復用推挽輸出,因為GPIO的主功能為PA0 IO口,這里使用其默認復用功能,故應將GPIO模式設置為復用推挽,使用普通的推挽輸出無法輸出PWM波形。
配置時基單元
/*選擇TIM時鐘*/TIM_InternalClockConfig(TIM2);
選擇TIM時鐘為內部時鐘
/*配置時基單元*/TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct; //定義一個TIM_TimeBaseInitTypeDef類型的結構體用于初始化時基單元TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1; //設置時鐘分頻模式為不分TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up; //計數方式設置為向上計數模式/*輸出的PWM波形的頻率為1kHz,分辨率為1%PWM頻率: Freq = CK_PSC / (PSC + 1) / (ARR + 1)PWM占空比: Duty = CCR / (ARR + 1)PWM分辨率: Reso = 1 / (ARR + 1)*/TIM_TimeBaseInitStruct.TIM_Period = 100-1; //ARR,自動加載重裝寄存器,要寫入自動重裝值TIM_TimeBaseInitStruct.TIM_Prescaler = 720-1; //PSC,預分頻器的分頻值TIM_TimeBaseInitStruct.TIM_RepetitionCounter = 0; //重復計數,只有高級定時器才會使用,通用定時器用不到TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStruct); //初始化時基單元
按照輸出PWM頻率為1kHz,分辨率為1%計算出ARR(自動重裝寄存器)和PSC(預分頻器)的值。
PWM頻率:? ? ? ? Freq = CK_PSC / (PSC + 1) / (ARR + 1)
PWM占空比:?? ?Duty = CCR / (ARR + 1)
PWM分辨率:?? ?Reso = 1 / (ARR + 1)?
?初始化輸出比較單元
/*初始化輸出比較單元*/TIM_OCInitTypeDef TIM_OCInitStruct; //定義一個TIM_OCInitTypeDef類型的結構體用以輸出比較單元初始化TIM_OCStructInit(&TIM_OCInitStruct); //給每個結構體成員賦初始值,防止因未使用到的結構體成員未初始化而導致程序出現錯誤TIM_OCInitStruct.TIM_OCMode = TIM_OCMode_PWM1; //選擇PWM模式1TIM_OCInitStruct.TIM_OCPolarity = TIM_OCPolarity_High; //OC1有效電平為高電平TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable; //輸出比較使能/*輸出PWM的波形占空比PWM占空比: Duty = CCR / (ARR + 1)*/TIM_OCInitStruct.TIM_Pulse = 0; //CCR,捕獲/比較器,本工程中有封裝的函數用于改變占空比,此處先設置為0TIM_OC1Init(TIM2,&TIM_OCInitStruct);
初始化輸出比較單元時,在初始化TIM輸出比較結構體之前調用TIM_OCStructInit()函數給結構體的每個成員初始化賦默認值,防止在實驗中未使用到輸出比較單元中的某些功能且未初始化這些功能對應的結構體成員時,發生意外錯誤。
將輸出比較單元的輸出模式設置為PWM模式1。
設置輸出極性為高電平有效,即PWM模式1下計數器的值小于CCR時為高電平,反之為低電平。
此處是通過設置捕獲比較使能寄存器TIMx_CCER位1CC1P設置輸入/捕獲1輸出極性
此處將CCR寄存器的值設置為0,實驗中使用封裝的函數?void PWM_SetComparel(uint16_t Compare)來調用TIM_SetCompare1()函數來改變CCR寄存器的值實現占空比的改變。
/*** @brief 指定CCR寄存器的值改變PWM Duty* @param None* @retval None* @note None
**/
void PWM_SetComparel(uint16_t Compare)
{TIM_SetCompare1(TIM2,Compare);
}
輸出比較通道重映射?
// RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE); //開啟AFIO時鐘
//
// /*
// 引腳重映射
// */
// GPIO_PinRemapConfig(GPIO_PartialRemap1_TIM2,ENABLE); //將TIM2的CH1從PA0重映射到PA15
// /*
// 解除引腳復用
// */
// GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable,ENABLE); //PA15引腳作為JTD1功能使用,此處解除AFIO的JTAG復用
在開啟TIM2和GPIOA時鐘后,開啟AFIO時鐘,調用GPIO_PinRemapConfig()將TIM2_CH1從PA0引腳重映射到PA15引腳。由于PA15默認為JTAG調試功能,調用GPIO_PinRemapConfig()函數解除引腳復用,PA15引腳作為JTD1功能使用,解除AFIO的JTAG復用。(如果不使用重映射功能,則忽略這部分)
輸入捕獲功能初始化
/*** @brief IC初始化* @param None* @retval None* @note 使用TIM3進行輸入捕獲
**/
void IC_Init(void)
{/*開啟時鐘*/RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE); //開啟TIM2時鐘RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE); //開啟GPIOA時鐘GPIO_InitTypeDef GPIO_InitStruct; //定義結構體GPIO_InitStruct.GPIO_Pin = GPIO_Pin_6; //選擇PA6 GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IPU; //選擇上拉輸入模式GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA,&GPIO_InitStruct);/*選擇TIM時鐘*/TIM_InternalClockConfig(TIM3);/*配置時基單元*/TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct; //定義一個TIM_TimeBaseInitTypeDef類型的結構體用于初始化時基單元TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1; //設置時鐘分頻模式為不分TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up; //計數方式設置為向上計數模式/*輸出的PWM波形的頻率為1kHz,分辨率為1%PWM頻率: Freq = CK_PSC / (PSC + 1) / (ARR + 1)PWM占空比: Duty = CCR / (ARR + 1)PWM分辨率: Reso = 1 / (ARR + 1)*/TIM_TimeBaseInitStruct.TIM_Period = 65536-1; //ARR,自動加載重裝寄存器,要寫入自動重裝值,將ARR的值設為最大值,防止溢出TIM_TimeBaseInitStruct.TIM_Prescaler = 72-1; //PSC,預分頻器的分頻值TIM_TimeBaseInitStruct.TIM_RepetitionCounter = 0; //重復計數,只有高級定時器才會使用,通用定時器用不到TIM_TimeBaseInit(TIM3,&TIM_TimeBaseInitStruct); //初始化時基單元/*初始化輸入捕獲單元*/TIM_ICInitTypeDef TIM_ICInitStruct; //定義結構體用于初始化輸入捕獲單元TIM_ICInitStruct.TIM_Channel = TIM_Channel_1; //選擇TIM3輸入捕獲通道1TIM_ICInitStruct.TIM_ICFilter = 0xF; //輸入濾波,濾除噪音,使信號更平滑,并不會改變輸入信號的頻率TIM_ICInitStruct.TIM_ICPolarity = TIM_ICPolarity_Rising; //選擇上升沿觸發 TIM_ICInitStruct.TIM_ICPrescaler = TIM_ICPSC_DIV1; //不分頻TIM_ICInitStruct.TIM_ICSelection = TIM_ICSelection_DirectTI;TIM_ICInit(TIM3,&TIM_ICInitStruct);/*觸發源選擇*/TIM_SelectInputTrigger(TIM3,TIM_TS_TI1FP1); //觸發源選擇濾波定時器輸入1/*選擇從模式*/TIM_SelectSlaveMode(TIM3,TIM_SlaveMode_Reset); //上升沿初始化計數器并觸發寄存器更新/*啟動定時器*/TIM_Cmd(TIM3,ENABLE);
}
?實驗中要實現輸入捕獲功能,需要用到兩個定時器,TIM2的CH1通道實現輸出比較功能,通過PA0引腳輸出PWM信號。通過PA6引腳輸入PWM信號,即TIM3的CH1通道實現輸入捕獲功能。
- 配置GPIO,選擇PA6引腳為上拉輸入模式
- 配置時基單元,將ARR的值設置為最大值65536,?防止溢出。
- 配置輸入捕獲單元,選擇TIM3輸入捕獲通道1,初始化輸入捕獲單元的TIM_ICInitTypeDef類型TIM_ICInitStruct結構體的成員TIM_ICFilter指定一個數值實現輸入濾波,濾除噪音,使信號更平滑(并不會改變輸入信號的頻率),邊沿檢測選擇上升沿觸發,分頻器配置為不分頻模式。
- 觸發源選擇,選擇濾波定時器輸入1
- 主模式已選擇為OC1(TIM2通道1的輸出比較功能)
- 從模式選擇為Reset模式,上升沿初始化計數器并觸發寄存器更新
- 啟動定時器
?計算捕獲PWM的頻率
/*** @brief 計算頻率值* @param None* @retval 輸出PWM的頻率* @note 讀取CCR的值計算頻率值
**/
uint32_t IC_GetFreq(void)
{return 1000000/(TIM_GetCapture1(TIM3)+1); //加1使為了消除測量的誤差,使輸出的頻率值恰好為1000Hz
}
?將該功能封裝,在函數中調用TIM_GetCapture1()函數讀取輸入捕獲通道1的值,使用測周法(𝑓𝑥=𝑓𝑐?/?𝑁),基準頻率為1kHz, N為捕獲通道1的值,將計算所得的頻率返回。
實驗結果
OLED顯示PWM的頻率
問題記錄
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