前言
TIM定時器(Timer):STM32的TIM定時器是一種功能強大的外設模塊,通過時基單元(包含預分頻器、計數器和自動重載寄存器)實現精準定時和計數功能。其核心原理是:內部時鐘(CK_INT)或外部時鐘經預分頻器分頻后驅動計數器,當計數器達到自動重載寄存器(ARR)設定的值時觸發更新事件,可產生中斷或DMA請求,并自動重置計數器重新開始計數。定時器分為高級定時器(TIM1/TIM8)、通用定時器(TIM2-5)和基本定時器(TIM6/TIM7),功能逐級遞減:高級定時器支持PWM生成、死區控制、剎車保護等復雜功能;通用定時器支持輸入捕獲、輸出比較及編碼器接口;基本定時器僅提供基礎定時中斷。通過配置預分頻值(PSC)和自動重載值(ARR),可靈活設置定時周期(T = (PSC+1)*(ARR+1)/時鐘頻率),并支持APB總線時鐘級聯擴展超長定時。此外,TIM還支持主從模式、外部時鐘輸入及硬件觸發DAC等高級應用,廣泛用于PWM控制、信號測量、定時任務調度等場景。
技術實現?
原理圖
無
接線圖
定時器定時中斷
代碼實現
main.c
#include "stm32f10x.h" // Device header
#include "Delay.h" //延時函數
#include "OLED.h"
#include "Timer.h"uint16_t Num = 0;int main(void)
{/*OLED初始化*/OLED_Init();/*定時器初始化*/Timer_Init();/*OLED顯示*/OLED_ShowString(1,1,"Num:"); //在第一行第一列開始顯示字符串OLED_ShowString(2,1,"Counter:"); //在第二行第一列開始顯示字符串while(1){OLED_ShowNum(1,5,Num,5); //顯示中斷計數變量NumOLED_ShowNum(2,9,TIM_GetCounter(TIM2),5); //顯示定時器當前計數器的值}
}
Timer.h?
#ifndef __TIMER_H__
#define __TIMER_H__#include "stm32f10x.h" // Device headervoid Timer_Init(void);#endif
Timer.c?
#include "Timer.h"extern uint16_t Num;
/**@brief 初始化通用定時器2*@param none *@retval none
**/
void Timer_Init(void)
{/*開啟高速總線APB1時鐘*/RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);/*選擇時鐘模式為內部時鐘,定時器時鐘頻率為72MHz*/TIM_InternalClockConfig(TIM2); //系統默認時鐘模式為內部時鐘模式,不調用該函數并不會影響時鐘模式配置為內部時鐘模式/*配置時基單元*/TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1; //選擇分頻模式為不分頻TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up; //選擇計數模式為向上計數/*預分頻值與自動重裝值計算計數器溢出頻率(計數器每秒記多少個數):CK_CNT_OV = 72MHz/(PSC + 1)/(ARR + 1)*/TIM_TimeBaseInitStruct.TIM_Period = 10000-1; //自動重裝值(當計數器到達該預設值會將重裝寄存器重新加載到計數寄存器中))TIM_TimeBaseInitStruct.TIM_Prescaler = 7200-1; //預分頻值TIM_TimeBaseInitStruct.TIM_RepetitionCounter= 0; //重復計數器,只有高級定時器才有,通用定時器用不到,直接賦值為0TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStruct);/***@note:該程序在復位后計數變量的值為1,說明復位后中斷函數在初始化后就立刻進入一次。* 原因是:因為預分頻器有個緩沖寄存器,我們寫的值只有在更新事件時才會起作用,* 為了使我們寫的值立刻起作用,在TIM_TimeBaseInt()函數末尾手動生成了一個更新事件,* 使預分頻器的值有效。但會使更新事件和更新中斷同時發生,更新中斷會置更新中斷標志位。* //Generate an update event to reload the Prescaler and the Repetition counter* //values immediately * TIMx->EGR = TIM_PSCReloadMode_Immediate; * TIM2_EGR寄存器中的UG位置一,重新初始化計數器,產生一個更新事件,然后會進入中斷
**//*清除更新中斷標志位*/TIM_ClearFlag(TIM2,TIM_FLAG_Update); //將更新標志位取反,取消更新事件/*使能中斷輸出控制*/TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE);/*配置NVIC*/NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); //NVIC優先級分組選擇分組2/*NVIC初始化*/NVIC_InitTypeDef NVIC_InitStruct;NVIC_InitStruct.NVIC_IRQChannel = TIM2_IRQn; //中斷通道選擇TIM2全局中斷NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE; //啟用NVIC通道NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 2;NVIC_InitStruct.NVIC_IRQChannelSubPriority = 1;NVIC_Init(&NVIC_InitStruct);/*啟動定時器*/TIM_Cmd(TIM2,ENABLE);
}/**@brief 通用定時器2中斷*@param none *@retval none
**/
void TIM2_IRQHandler(void)
{if(TIM_GetITStatus(TIM2,TIM_IT_Update) == SET) //獲取TIM中斷標志位{Num++;TIM_ClearITPendingBit(TIM2,TIM_IT_Update); //清除中斷標志位}
}
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_Front.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
TIMx?
? ? ? ? 通用定時器是一個通過可編程預分頻器驅動的16位自動裝載計數器構成,適用于多場合,包括測量輸入信號的脈沖長度(輸入捕獲)或產生輸出波形(輸出比較和PWM).每個定時器完全獨立,沒有互相共享任何資源,它們可以一起同步操作。
TIMx?主要功能
通用TIMx(TIM2,TIM3,TIM4和TIM5)定時器功能包括:
- 16位向上,向下,向上/向下自動裝載計數器
- 16位可編程(可實時修改)預分頻器,計數器時鐘頻率的分頻系數為1~65536之間的任意數值
- 4個獨立通道:
? ? ? ? --輸入捕獲
? ? ? ? --輸出比較
? ? ? ? --PWM生成(邊沿或中間對齊模式)
? ? ? ? --單脈沖模式輸出
- 使用外部信號控制定時器和定時器互連的同步電路
- 如下事件發生時產生中斷/DMA
? ? ? ? --更新:計數器向上溢出/向下溢出,計數器初始化(通過軟件或內部/外部觸發計數)
? ? ? ? --觸發事件(計數器啟動,停止,初始化或者由內部/外部觸發計數)
? ? ? ? --輸入捕獲
? ? ? ? --輸出比較
- 支持針對定位的增量(正交)編碼器和霍爾傳感器電路
- 觸發輸入作為外部時鐘或按中期的電流管理
定時器初始化
1.時鐘設置
/*開啟高速總線APB1時鐘*/RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);
TIM2屬于APB1外圍設備,應調用函數RCC_APB1PeriphClockCmd()這只APB1時鐘。
2.選擇計數器時鐘
????????計數器時鐘可由下列時鐘源提供:
????????● 內部時鐘(CK_INT)
????????● 外部時鐘模式1:外部輸入腳(TIx)
????????● 外部時鐘模式2:外部觸發輸入(ETR)
????????● 內部觸發輸入(ITRx):使用一個定時器作為另一個定時器的預分頻器,如可以配置一個定時
????????????????器Timer1而作為另一個定時器Timer2的預分頻器
/*選擇時鐘模式為內部時鐘,定時器時鐘頻率為72MHz*/TIM_InternalClockConfig(TIM2); //系統默認時鐘模式為內部時鐘模式,不調用該函數并不會影響時鐘模式配置為內部時鐘模式
調用TIM_InternalClockConfig()函數將TIM2定時器的時鐘配置為內部時鐘,此時時鐘頻率為72MHz
3.設置時基單元?
時基單元
可編程通用定時器的主要部分是一個16位計數器和與其相關的自動裝載寄存器,這個計數器可以向上計數,向下計數或者向上向下雙向計數。此計數器時鐘由預分頻器分頻得到。
時基單元包含:
- 計數器寄存器(TIMx_CNT)
- 預分頻器寄存器(TIMx_PSC)
- 自動裝載寄存器(TIMx_ARR)
/*配置時基單元*/TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1; //選擇分頻模式為不分頻TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up; //選擇計數模式為向上計數/*預分頻值與自動重裝值計算計數器溢出頻率(計數器每秒記多少個數):CK_CNT_OV = 72MHz/(PSC + 1)/(ARR + 1)*/TIM_TimeBaseInitStruct.TIM_Period = 10000-1; //自動重裝值(當計數器到達該預設值會將重裝寄存器重新加載到計數寄存器中))TIM_TimeBaseInitStruct.TIM_Prescaler = 7200-1; //預分頻值TIM_TimeBaseInitStruct.TIM_RepetitionCounter= 0; //重復計數器,只有高級定時器才有,通用定時器用不到,直接賦值為0TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStruct);
將分頻模式配置為不分頻模式,計數器的計數模式設置為向上計數。然后進行預分頻值和自動重裝值的的計算。計數器溢出頻率(定時器每秒觸發中斷的次數):CK_CNT_OV = 72MHz/(PSC + 1)/(ARR + 1),這是要求每秒計1個數(每秒觸發一次中斷),CK_CNT_OV值為1Hz,PSC(預分頻器的值)和ARR(自動重裝值)分別設置為7200和10000,即記一個數需要100us,計數值到達10000時說明定時器定時到達1S。
(51單片機是一個機器周期(12個時鐘周期)計一個數,而STM32是一個時鐘周期記一個數) ,通用計數器用不到重復計數器,只有高級計數器才會用到,此處直接賦值為0.
1. 51單片機的計數機制
(1) 機器周期與指令周期
- 時鐘周期:51單片機的晶振頻率(如12MHz)決定了時鐘周期(1/12 μs)。
- 機器周期:
- 51單片機采用馮諾依曼架構,每條指令的執行需要?12個時鐘周期(即1個機器周期)。
- 例如:若晶振為12MHz,則1個機器周期 =?1 μs(12個時鐘周期)。
- 定時器計數:
- 定時器(如Timer0)默認以機器周期為計數單位,即每過1個機器周期(1 μs)計數一次。
- 例如:設置定時器溢出值為1000時,溢出時間為?1000 × 1 μs = 1秒。
2. STM32的計數機制
(1) 指令周期與定時器時鐘
- 時鐘周期:STM32采用哈佛架構,每個指令執行僅需?1個時鐘周期(相比51的12周期效率更高)。
- 定時器計數時鐘(CK_CNT):
- 定時器的計數時鐘由**預分頻器(PSC)**分頻而來,分頻公式為:
CK_CNT=系統時鐘(如72MHz)/PSC+1
- 每個CK_CNT周期,計數器遞增1次(無需等待指令周期)。
- 例如:若PSC=71,則CK_CNT =?72?MHz72=1?MHz7272MHz?=1MHz,即每?1 μs?計數一次。
(2) 計數靈活性
- 直接基于時鐘分頻:
STM32的計數器直接由CK_CNT驅動,無需綁定到指令周期,因此可以實現任意分頻比(通過PSC和ARR的靈活配置)。- 高精度計數:
例如:若系統時鐘為72MHz,PSC=0(不分頻),則CK_CNT=72MHz,計數器每?13.89 ns?遞增一次,精度遠高于51單片機。
3. 關鍵對比
特性 51單片機 STM32 架構 馮諾依曼架構(程序與數據共享總線) 哈佛架構(程序與數據獨立總線) 指令周期 每條指令需12個時鐘周期(1機器周期) 每條指令僅需1個時鐘周期 定時器計數單位 機器周期(12時鐘周期) 可配置的時鐘分頻(CK_CNT) 計數靈活性 固定為機器周期的分頻(如12分頻) 可通過PSC和ARR實現任意分頻比 典型定時精度 1 μs(12MHz晶振時) 13.89 ns(72MHz系統時鐘,不分頻時)
4. 實際應用中的差異
(1) 定時1秒的配置
- 51單片機(12MHz晶振):
- 定時器溢出值 = 1秒 / 1 μs =?1000(無需分頻,直接使用機器周期)。
- STM32(72MHz系統時鐘):
- 需配置PSC和ARR:
- PSC = 71999 → 分頻系數=72000 → CK_CNT =?72?MHz72000=1?kHz7200072MHz?=1kHz
- ARR = 999 → 總計數周期 = 1000 →?1秒。
(2) PWM輸出
- 51單片機:
- PWM頻率受限于機器周期,難以實現高頻信號。
- STM32:
- 可通過PSC和ARR靈活配置PWM頻率,例如:
- PSC=0(CK_CNT=72MHz) → 高頻PWM(如1MHz)。
5. 總結
- 51單片機:定時器基于固定機器周期(12時鐘周期),計數靈活性較低,適合簡單定時任務。
- STM32:定時器直接基于可編程的時鐘分頻(CK_CNT),每個時鐘周期可計數一次,提供極高的靈活性和精度,適合復雜實時控制場景。
/*清除更新中斷標志位*/TIM_ClearFlag(TIM2,TIM_FLAG_Update); //將更新標志位取反,取消更新事件
?清除中斷更新中斷標志位,防止上電復位后立即進入中斷。
該程序在復位后計數變量的值為1,說明復位后中斷函數在初始化后就立刻進入一次。
?原因是:因為預分頻器有個緩沖寄存器,我們寫的值只有在更新事件時才會起作用,
?為了使我們寫的值立刻起作用,在TIM_TimeBaseInt()函數末尾手動生成了一個更新事件,
使預分頻器的值有效。但會使更新事件和更新中斷同時發生,更新中斷會置更新中斷標志位。
? *?? ??? ?//Generate an update event to reload the Prescaler and the Repetition counter
? *?? ??? ??? ?//values immediately?
? *?? ??? ?TIMx->EGR = TIM_PSCReloadMode_Immediate; ??
TIM2_EGR寄存器中的UG位置一,重新初始化計數器,產生一個更新事件,然后會進入中斷?
4.輸出中斷控制?
/*使能中斷輸出控制*/TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE);
選擇TIM2外設,啟用TIM更新中斷源。
5.配置NVIC?
/*配置NVIC*/NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); //NVIC優先級分組選擇分組2/*NVIC初始化*/NVIC_InitTypeDef NVIC_InitStruct;NVIC_InitStruct.NVIC_IRQChannel = TIM2_IRQn; //中斷通道選擇TIM2全局中斷NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE; //啟用NVIC通道NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 2;NVIC_InitStruct.NVIC_IRQChannelSubPriority = 1;NVIC_Init(&NVIC_InitStruct);
選擇NVIC優先級分組為NVIC_PriorityGroup_2,將TIM2全局中斷設置為中斷通道,搶占優先級設置為2,響應優先級設置為1(在合法范圍內靈活設置即可)
6.啟用定時器
/*啟動定時器*/TIM_Cmd(TIM2,ENABLE);
調用TIM_Cmd()函數啟用指定的TIMx外設。
定時器中斷
**@brief 通用定時器2中斷*@param none *@retval none
**/
void TIM2_IRQHandler(void)
{if(TIM_GetITStatus(TIM2,TIM_IT_Update) == SET) //獲取TIM中斷標志位{Num++;TIM_ClearITPendingBit(TIM2,TIM_IT_Update); //清除中斷標志位}
}
TIM2定時器中斷函數名在啟動文件中的定義為TIM2_IRQHandler,此處應嚴格按照啟動文件中的定義。TIM2 1s發生一次中斷,進入中斷函數后檢測TIM2中斷標志位,若中斷標志位被置1則執行中斷任務,計數變量加1,然后清除中斷標志位,避免ISR無限循環。
中斷發生需要滿足兩個條件:
- 中斷使能:對應中斷的使能位(如USART_CR1中的RXNEIE)被置1。
- 中斷標志位置位:硬件事件發生后,對應的中斷標志位(如USART_SR中的RXNE或ORE)被自動置1。
即使中斷使能已打開,只有當標志位被置位時,才會觸發中斷。因此,進入ISR后必須通過檢測標志位來確認具體是哪個事件觸發了中斷。
?數據顯示
OLED_ShowString(1,1,"Num:"); //在第一行第一列開始顯示字符串OLED_ShowString(2,1,"Counter:"); //在第二行第一列開始顯示字符串while(1){OLED_ShowNum(1,5,Num,5); //顯示中斷計數變量NumOLED_ShowNum(2,9,TIM_GetCounter(TIM2),5); //顯示定時器當前計數器的值}
在OLED第一行顯示計數變量Num的值,即x秒。第二行顯示計數器寄存器中的值即x*10us,該數據使用TIM_GetCounter函數獲取。