历史上的今天
今天是：2025年03月13日（星期四）
2019年03月13日 | STM32 关于定时器相关问题的探讨
2019-03-13 来源：eefocus
STM32F4 PWM模块探讨
1.STM32定时器认识
1.1 基本定时器
基本定时器 TIM6 和 TIM7 包含一个 16 位自动重载计数器，该计数器由可编程预分频器驱动。此类定时器不仅可用作通用定时器以生成时基， 还可以专门用于驱动数模转换器 。(DAC)。
通用定时器特性
16 位自动重载递增计数器
16 位可编程预分频器，用于对计数器时钟频率进行分频（即运行时修改），分频系数
介于 1 和 65536 之间
用于触发 DAC 的同步电路
发生如下更新事件时会生成中断/DMA 请求：计数器上溢
1.2 通用定时器
1.2.1 TIM~TIM5
通用定时器包含一个 16 位或 32 位自动重载计数器，该计数器由可编程预分频器驱动。可用于多种用途，包括测量输入信号的脉冲宽度（输入捕获）或生成输出波形（输出比
较和 PWM）。使用定时器预分频器和 RCC 时钟控制器预分频器，可将脉冲宽度和波形周期从几微秒调制到几毫秒。这些定时器彼此完全独立，不共享任何资源。
TIM2~TIM5特性
16 位（TIM3 和 TIM4）或 32 位（TIM2 和 TIM5） 递增、递减和递增/递减自动重载计数器。
16位可编程预分频器，用于对计数器时钟频率进行分频（即运行时修改），分频系数介于 1 到 65536 之间。
多达 4 个独立通道，可用于：
输入捕获
输出比较
PWM 生成（边沿和中心对齐模式）
单脉冲模式输出
使用外部信号控制定时器且可实现多个定时器互连的同步电路。
发生如下事件时生成中断/DMA 请求：
更新：计数器上溢/下溢、计数器初始化（通过软件或内部/外部触发）
触发事件（计数器启动、停止、初始化或通过内部/外部触发计数）
输入捕获
输出比较
支持定位用增量（正交）编码器和霍尔传感器电路 、
外部时钟触发输入或逐周期电流管理
1.2.2 TIM9 ~ TIM14
IM9 到 TIM14 通用定时器包含一个 16 位自动重载计数器，该计数器由可编程预分频器驱动。它们可用于多种用途，包括测量输入信号的脉冲宽度（输入捕获），或者生成输出波形（输出比较、 PWM）。使用定时器预分频器和 RCC 时钟控制器预分频器，可将脉冲宽度和波形周期从几微秒调制到几毫秒。TIM9 到 TIM14 定时器彼此完全独立，不共享任何资源。
TIM9~TIM12 特性
16 位自动重载递增计数器（属于中等容量器件）
16 位可编程预分频器，用于对计数器时钟频率进行分频（即运行时修改），分频系数
多达 2 个独立通道，可用于：
输入捕获
输出比较 PWM 生成（边沿对齐模式）
单脉冲模式输出
使用外部信号控制定时器且可实现多个定时器互连的同步电路
发生如下事件时生成中断：
更新：计数器上溢、计数器初始化（通过软件或内部触发）
触发事件（计数器启动、停止、初始化或者由内部触发计数）
输入捕获
输出比较
1.3 高级定时器
高级控制定时器（TIM1 和 TIM8）包含一个 16 位自动重载计数器，该计数器由可编程预分频器驱动。此类定时器可用于各种用途，包括测量输入信号的脉冲宽度（输入捕获），或者生成输出波形（输出比较、 PWM 和带死区插入的互补 PWM）。使用定时器预分频器和 RCC 时钟控制器预分频器，可将脉冲宽度和波形周期从几微秒调制到几毫秒。高级控制定时器（TIM1 和 TIM8）和通用 (TIMx) 定时器彼此完全独立，不共享任何资源。
TIM1 和 TIM8特性：
16 位递增、递减、递增/递减自动重载计数器。
16 位可编程预分频器，用于对计数器时钟频率进行分频（即运行时修改），分频系数
介于 1 到 65536 之间。
多达 4 个独立通道，可用于：
输入捕获
输出比较
PWM 生成（边沿和中心对齐模式）
单脉冲模式输出
带可编程死区的互补输出。
使用外部信号控制定时器且可实现多个定时器互连的同步电路。
重复计数器，用于仅在给定数目的计数器周期后更新定时器寄存器。
用于将定时器的输出信号置于复位状态或已知状态的断路输入。
发生如下事件时生成中断/DMA 请求：
更新：计数器上溢/下溢、计数器初始化（通过软件或内部/外部触发）
触发事件（计数器启动、停止、初始化或通过内部/外部触发计数）
输入捕获
输出比较
断路输入
支持定位用增量（正交）编码器和霍尔传感器电路。
外部时钟触发输入或逐周期电流管理。
2.定时器相关配置参数
2.1初始化基本定时参数
/**
* @brief TIM Time Base Init structure definition
* @note This structure is used with all TIMx except for TIM6 and TIM7.
*/
typedef struct
{
uint16_t TIM_Prescaler; /*!< Specifies the prescaler value used to divide the TIM clock.
This parameter can be a number between 0x0000 and 0xFFFF */
uint16_t TIM_CounterMode; /*!< Specifies the counter mode.
This parameter can be a value of @ref TIM_Counter_Mode */
uint32_t TIM_Period; /*!< Specifies the period value to be loaded into the active
Auto-Reload Register at the next update event.
This parameter must be a number between 0x0000 and 0xFFFF. */
uint16_t TIM_ClockDivision; /*!< Specifies the clock division.
This parameter can be a value of @ref TIM_Clock_Division_CKD */
uint8_t TIM_RepetitionCounter; /*!< Specifies the repetition counter value. Each time the RCR downcounter
reaches zero, an update event is generated and counting restarts
from the RCR value (N).
This means in PWM mode that (N+1) corresponds to:
- the number of PWM periods in edge-aligned mode
- the number of half PWM period in center-aligned mode
This parameter must be a number between 0x00 and 0xFF.
@note This parameter is valid only for TIM1 and TIM8. */
} TIM_TimeBaseInitTypeDef;
2.2 输出比较参数
/**
* @brief TIM Output Compare Init structure definition
*/
typedef struct
{
uint16_t TIM_OCMode; /*!< Specifies the TIM mode.
This parameter can be a value of @ref TIM_Output_Compare_and_PWM_modes */
uint16_t TIM_OutputState; /*!< Specifies the TIM Output Compare state.
This parameter can be a value of @ref TIM_Output_Compare_State */
uint16_t TIM_OutputNState; /*!< Specifies the TIM complementary Output Compare state.
This parameter can be a value of @ref TIM_Output_Compare_N_State
@note This parameter is valid only for TIM1 and TIM8. */
uint32_t TIM_Pulse; /*!< Specifies the pulse value to be loaded into the Capture Compare Register.
This parameter can be a number between 0x0000 and 0xFFFF */
uint16_t TIM_OCPolarity; /*!< Specifies the output polarity.
This parameter can be a value of @ref TIM_Output_Compare_Polarity */
uint16_t TIM_OCNPolarity; /*!< Specifies the complementary output polarity.
This parameter can be a value of @ref TIM_Output_Compare_N_Polarity
@note This parameter is valid only for TIM1 and TIM8. */
uint16_t TIM_OCIdleState; /*!< Specifies the TIM Output Compare pin state during Idle state.
This parameter can be a value of @ref TIM_Output_Compare_Idle_State
@note This parameter is valid only for TIM1 and TIM8. */
uint16_t TIM_OCNIdleState; /*!< Specifies the TIM Output Compare pin state during Idle state.
This parameter can be a value of @ref TIM_Output_Compare_N_Idle_State
@note This parameter is valid only for TIM1 and TIM8. */
} TIM_OCInitTypeDef;
2.3 输入比较参数初始化
/**
* @brief TIM Input Capture Init structure definition
*/
typedef struct
{
uint16_t TIM_Channel; /*!< Specifies the TIM channel.
This parameter can be a value of @ref TIM_Channel */
uint16_t TIM_ICPolarity; /*!< Specifies the active edge of the input signal.
This parameter can be a value of @ref TIM_Input_Capture_Polarity */
uint16_t TIM_ICSelection; /*!< Specifies the input.
This parameter can be a value of @ref TIM_Input_Capture_Selection */
uint16_t TIM_ICPrescaler; /*!< Specifies the Input Capture Prescaler.
This parameter can be a value of @ref TIM_Input_Capture_Prescaler */
uint16_t TIM_ICFilter; /*!< Specifies the input capture filter.
This parameter can be a number between 0x0 and 0xF */
} TIM_ICInitTypeDef;
2.4 TIM1 and TIM8 高级定时器死区初始化
/**
* @brief BDTR structure definition
* @note This structure is used only with TIM1 and TIM8.
*/
typedef struct
{
uint16_t TIM_OSSRState; /*!< Specifies the Off-State selection used in Run mode.
This parameter can be a value of @ref TIM_OSSR_Off_State_Selection_for_Run_mode_state */
uint16_t TIM_OSSIState; /*!< Specifies the Off-State used in Idle state.
This parameter can be a value of @ref TIM_OSSI_Off_State_Selection_for_Idle_mode_state */
uint16_t TIM_LOCKLevel; /*!< Specifies the LOCK level parameters.
This parameter can be a value of @ref TIM_Lock_level */
uint16_t TIM_DeadTime; /*!< Specifies the delay time between the switching-off and the
switching-on of the outputs.
This parameter can be a number between 0x00 and 0xFF */
uint16_t TIM_Break; /*!< Specifies whether the TIM Break input is enabled or not.
This parameter can be a value of @ref TIM_Break_Input_enable_disable */
uint16_t TIM_BreakPolarity; /*!< Specifies the TIM Break Input pin polarity.
This parameter can be a value of @ref TIM_Break_Polarity */
uint16_t TIM_AutomaticOutput; /*!< Specifies whether the TIM Automatic Output feature is enabled or not.
This parameter can be a value of @ref TIM_AOE_Bit_Set_Reset */
} TIM_BDTRInitTypeDef;
2.5 相关库函数
/* Exported macro ------------------------------------------------------------*/
/* Exported functions --------------------------------------------------------*/
/* TimeBase management ********************************************************/
void TIM_DeInit(TIM_TypeDef* TIMx);
void TIM_TimeBaseInit(TIM_TypeDef* TIMx, TIM_TimeBaseInitTypeDef* TIM_TimeBaseInitStruct);
void TIM_TimeBaseStructInit(TIM_TimeBaseInitTypeDef* TIM_TimeBaseInitStruct);
void TIM_PrescalerConfig(TIM_TypeDef* TIMx, uint16_t Prescaler, uint16_t TIM_PSCReloadMode);
void TIM_CounterModeConfig(TIM_TypeDef* TIMx, uint16_t TIM_CounterMode);
void TIM_SetCounter(TIM_TypeDef* TIMx, uint32_t Counter);
void TIM_SetAutoreload(TIM_TypeDef* TIMx, uint32_t Autoreload);
uint32_t TIM_GetCounter(TIM_TypeDef* TIMx);
uint16_t TIM_GetPrescaler(TIM_TypeDef* TIMx);
void TIM_UpdateDisableConfig(TIM_TypeDef* TIMx, FunctionalState NewState);
void TIM_UpdateRequestConfig(TIM_TypeDef* TIMx, uint16_t TIM_UpdateSource);
void TIM_ARRPreloadConfig(TIM_TypeDef* TIMx, FunctionalState NewState);
void TIM_SelectOnePulseMode(TIM_TypeDef* TIMx, uint16_t TIM_OPMode);
void TIM_SetClockDivision(TIM_TypeDef* TIMx, uint16_t TIM_CKD);
void TIM_Cmd(TIM_TypeDef* TIMx, FunctionalState NewState);
/* Output Compare management **************************************************/
void TIM_OC1Init(TIM_TypeDef* TIMx, TIM_OCInitTypeDef* TIM_OCInitStruct);
void TIM_OC2Init(TIM_TypeDef* TIMx, TIM_OCInitTypeDef* TIM_OCInitStruct);
void TIM_OC3Init(TIM_TypeDef* TIMx, TIM_OCInitTypeDef* TIM_OCInitStruct);
void TIM_OC4Init(TIM_TypeDef* TIMx, TIM_OCInitTypeDef* TIM_OCInitStruct);
void TIM_OCStructInit(TIM_OCInitTypeDef* TIM_OCInitStruct);
void TIM_SelectOCxM(TIM_TypeDef* TIMx, uint16_t TIM_Channel, uint16_t TIM_OCMode);
void TIM_SetCompare1(TIM_TypeDef* TIMx, uint32_t Compare1);
void TIM_SetCompare2(TIM_TypeDef* TIMx, uint32_t Compare2);
void TIM_SetCompare3(TIM_TypeDef* TIMx, uint32_t Compare3);
void TIM_SetCompare4(TIM_TypeDef* TIMx, uint32_t Compare4);
void TIM_ForcedOC1Config(TIM_TypeDef* TIMx, uint16_t TIM_ForcedAction);
void TIM_ForcedOC2Config(TIM_TypeDef* TIMx, uint16_t TIM_ForcedAction);
void TIM_ForcedOC3Config(TIM_TypeDef* TIMx, uint16_t TIM_ForcedAction);
void TIM_ForcedOC4Config(TIM_TypeDef* TIMx, uint16_t TIM_ForcedAction);
void TIM_OC1PreloadConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPreload);
void TIM_OC2PreloadConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPreload);
void TIM_OC3PreloadConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPreload);
void TIM_OC4PreloadConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPreload);
void TIM_OC1FastConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCFast);
void TIM_OC2FastConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCFast);
void TIM_OC3FastConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCFast);
void TIM_OC4FastConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCFast);
void TIM_ClearOC1Ref(TIM_TypeDef* TIMx, uint16_t TIM_OCClear);
void TIM_ClearOC2Ref(TIM_TypeDef* TIMx, uint16_t TIM_OCClear);
void TIM_ClearOC3Ref(TIM_TypeDef* TIMx, uint16_t TIM_OCClear);
void TIM_ClearOC4Ref(TIM_TypeDef* TIMx, uint16_t TIM_OCClear);
void TIM_OC1PolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPolarity);
void TIM_OC1NPolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCNPolarity);
void TIM_OC2PolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPolarity);
void TIM_OC2NPolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCNPolarity);
void TIM_OC3PolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPolarity);
void TIM_OC3NPolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCNPolarity);
void TIM_OC4PolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPolarity);
void TIM_CCxCmd(TIM_TypeDef* TIMx, uint16_t TIM_Channel, uint16_t TIM_CCx);
void TIM_CCxNCmd(TIM_TypeDef* TIMx, uint16_t TIM_Channel, uint16_t TIM_CCxN);
/* Input Capture management ***************************************************/
void TIM_ICInit(TIM_TypeDef* TIMx, TIM_ICInitTypeDef* TIM_ICInitStruct);
void TIM_ICStructInit(TIM_ICInitTypeDef* TIM_ICInitStruct);
void TIM_PWMIConfig(TIM_TypeDef* TIMx, TIM_ICInitTypeDef* TIM_ICInitStruct);
uint32_t TIM_GetCapture1(TIM_TypeDef* TIMx);
uint32_t TIM_GetCapture2(TIM_TypeDef* TIMx);
uint32_t TIM_GetCapture3(TIM_TypeDef* TIMx);
uint32_t TIM_GetCapture4(TIM_TypeDef* TIMx);
void TIM_SetIC1Prescaler(TIM_TypeDef* TIMx, uint16_t TIM_ICPSC);
void TIM_SetIC2Prescaler(TIM_TypeDef* TIMx, uint16_t TIM_ICPSC);
void TIM_SetIC3Prescaler(TIM_TypeDef* TIMx, uint16_t TIM_ICPSC);
void TIM_SetIC4Prescaler(TIM_TypeDef* TIMx, uint16_t TIM_ICPSC);
/* Advanced-control timers (TIM1 and TIM8) specific features ******************/
void TIM_BDTRConfig(TIM_TypeDef* TIMx, TIM_BDTRInitTypeDef *TIM_BDTRInitStruct);
void TIM_BDTRStructInit(TIM_BDTRInitTypeDef* TIM_BDTRInitStruct);
void TIM_CtrlPWMOutputs(TIM_TypeDef* TIMx, FunctionalState NewState);
void TIM_SelectCOM(TIM_TypeDef* TIMx, FunctionalState NewState);
void TIM_CCPreloadControl(TIM_TypeDef* TIMx, FunctionalState NewState);
/* Interrupts, DMA and flags management ***************************************/
void TIM_ITConfig(TIM_TypeDef* TIMx, uint16_t TIM_IT, FunctionalState NewState);
void TIM_GenerateEvent(TIM_TypeDef* TIMx, uint16_t TIM_EventSource);
FlagStatus TIM_GetFlagStatus(TIM_TypeDef* TIMx, uint16_t TIM_FLAG);
void TIM_ClearFlag(TIM_TypeDef* TIMx, uint16_t TIM_FLAG);
ITStatus TIM_GetITStatus(TIM_TypeDef* TIMx, uint16_t TIM_IT);
void TIM_ClearITPendingBit(TIM_TypeDef* TIMx, uint16_t TIM_IT);
void TIM_DMAConfig(TIM_TypeDef* TIMx, uint16_t TIM_DMABase, uint16_t TIM_DMABurstLength);
void TIM_DMACmd(TIM_TypeDef* TIMx, uint16_t TIM_DMASource, FunctionalState NewState);
void TIM_SelectCCDMA(TIM_TypeDef* TIMx, FunctionalState NewState);
/* Clocks management **********************************************************/
void TIM_InternalClockConfig(TIM_TypeDef* TIMx);
void TIM_ITRxExternalClockConfig(TIM_TypeDef* TIMx, uint16_t TIM_InputTriggerSource);
void TIM_TIxExternalClockConfig(TIM_TypeDef* TIMx, uint16_t TIM_TIxExternalCLKSource,
uint16_t TIM_ICPolarity, uint16_t ICFilter);
void TIM_ETRClockMode1Config(TIM_TypeDef* TIMx, uint16_t TIM_ExtTRGPrescaler, uint16_t TIM_ExtTRGPolarity,
uint16_t ExtTRGFilter);
void TIM_ETRClockMode2Config(TIM_TypeDef* TIMx, uint16_t TIM_ExtTRGPrescaler,
uint16_t TIM_ExtTRGPolarity, uint16_t ExtTRGFilter);
/* Synchronization management *************************************************/
void TIM_SelectInputTrigger(TIM_TypeDef* TIMx, uint16_t TIM_InputTriggerSource);
void TIM_SelectOutputTrigger(TIM_TypeDef* TIMx, uint16_t TIM_TRGOSource);
void TIM_SelectSlaveMode(TIM_TypeDef* TIMx, uint16_t TIM_SlaveMode);
void TIM_SelectMasterSlaveMode(TIM_TypeDef* TIMx, uint16_t TIM_MasterSlaveMode);
void TIM_ETRConfig(TIM_TypeDef* TIMx, uint16_t TIM_ExtTRGPrescaler, uint16_t TIM_ExtTRGPolarity,
uint16_t ExtTRGFilter);
/* Specific interface management **********************************************/
void TIM_EncoderInterfaceConfig(TIM_TypeDef* TIMx, uint16_t TIM_EncoderMode,
uint16_t TIM_IC1Polarity, uint16_t TIM_IC2Polarity);
void TIM_SelectHallSensor(TIM_TypeDef* TIMx, FunctionalState NewState);
/* Specific remapping management **********************************************/
void TIM_RemapConfig(TIM_TypeDef* TIMx, uint16_t TIM_Remap);
3.相关要求及测试要点
3.1基本要求
对高级控制定时器进行正确的参数配置，使其输出4个不同占空比的PWM波形，输出占空比值显示在LCD上，并用示波器测量校验。
通道 1 2 3 4
占空比 12.5 25% 37.5% 50%
3.2发挥要求
PWM输出外接控制电路，在不同输出频率下调节占空比，驱动发光二极管控制其亮度，或者驱动直流电动机控制其转速。
输出SPWM信号，用示波器测量并显示。
3.3 硬件要求
外接按键控制电路
外接发光二极管
外接滤波电路，输出SPWM波
4.硬件设计
4.1LED驱动电路
利用单片机产生得PWM驱动电路直接驱动LED电路来验证，当输出PWM宽度变化时可以看到此时LED亮度变化，此时只需要将LED上拉就可以实现验证。当输入为低电平时，LED灯发光
4.2 SPWM滤波方案
利用高级定时器，我们能产生一系列PWM脉宽随时间变化的PWM波形，通过简单的RC滤波就可以将SPWM滤波成正弦波
5.软件设计过程
5.1 四路pwm输出配置
5.1.1 GPIO初始化
初始化引脚（PA6、PA7，PB0、PB1），这里拿出初始化PA6例子
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
GPIO_PinAFConfig(GPIOA,GPIO_PinSource6,GPIO_AF_TIM3);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOA,&GPIO_InitStructure);
5.1.2 定时器初始化配置
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_ARRPreloadConfig(TIM3,ENABLE);
TIM_TimeBaseStructure.TIM_Prescaler=psc;
TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_Period=arr;
TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1;
TIM_TimeBaseInit(TIM3,&TIM_TimeBaseStructure);
TIM_Cmd(TIM3, ENABLE);
5.1.3 pwm输出配置
这里同样拿出PA6引脚对应得配置过程
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_Pulse=0;
TIM_OC1Init(TIM3, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);
TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE);
TIM_CtrlPWMOutputs(TIM3,ENABLE);
5.2 占空比实现
TIM3_PWM_Init(arr-1,7-1);//tim3初始化
TIM_SetCompare1(TIM3,duty1);
TIM_SetCompare2(TIM3,duty2);
TIM_SetCompare3(TIM3,duty3);
TIM_SetCompare4(TIM3,duty4);
实验现象对比图
5.3 输出显示
显示代码：
OLED_ShowString(0,0,"Chann1:",16);
OLED_ShowFloatNum(56,0,(float)duty1/arr*100,7,16);
OLED_ShowString(112,0,"%",16);
OLED_ShowString(0,16,"Chann2:",16);
OLED_ShowFloatNum(56,16,(float)duty2/arr*100,7,16);
OLED_ShowString(112,16,"%",16);
OLED_ShowString(0,32,"Chann3:",16);
OLED_ShowFloatNum(56,32,(float)duty3/arr*100,7,16);
OLED_ShowString(112,32,"%",16);
OLED_ShowString(0,48,"Chann4:",16);
OLED_ShowFloatNum(56,48,(float)duty4/arr*100,7,16);
OLED_ShowString(112,48,"%",16);
实验现象图：
5.4 占空比调节
5.4.1按键设计模块
case 1: if(chmode == 1) chmode = 2;
else if(chmode == 2) chmode = 3;
else if(chmode == 3) chmode = 4;
else if(chmode == 4) chmode = 1;
key=0;break;
case 2: if(chmode == 1) duty1 += duty_index;
else if(chmode == 2) duty2 += duty_index;
else if(chmode == 3) duty3 += duty_index;
else if(chmode == 4) duty4 += duty_index;
key=0;break;
case 3: if(chmode == 1) duty1 -= duty_index;
else if(chmode == 2) duty2 -= duty_index;
else if(chmode == 3) duty3 -= duty_index;
else if(chmode == 4) duty4 -= duty_index;
key=0;break;//
case 4: if(duty_index == 1) duty_index = 2;
else if(duty_index == 2) duty_index = 4;
else if(duty_index == 4) duty_index = 5;
else if(duty_index == 5) duty_index = 6;
else if(duty_index == 6) duty_index = 10;
else if(duty_index == 10) duty_index = 40;
else if(duty_index == 40) duty_index = 1;
key=0;break;//
case 5: arr+=50;
key=0;break;//
case 6: arr-=50;
key=0;break;
5.4.2 显示模块
OLED_ShowString(0,0,"dutyIndex:",16);
OLED_ShowNum(80,0,duty_index,2,16);
OLED_ShowString(0,16,"Channel:",16);
OLED_ShowNum(64,16,chmode,1,16);
OLED_ShowString(0,32,"TIM1->ARR:",16);
OLED_ShowNum(80,32,arr,4,16);
实物现象对比图
通过按键1来切换不同的通道，按键2/3控制占空比的增减
5.5 spwm设计
对于高级定时器，可以添加死区
5.5.1 死区初始化
TIM_BDTRInitTypeDef TIM_BDTRInitStructure;
TIM_BDTRInitStructure.TIM_AutomaticOutput=TIM_AutomaticOutput_Enable;
TIM_BDTRInitStructure.TIM_Break= TIM_Break_Disable;
TIM_BDTRInitStructure.TIM_BreakPolarity=TIM_BreakPolarity_High;
TIM_BDTRInitStructure.TIM_DeadTime=dead;//¸øËÀÇøʱ¼ä
TIM_BDTRInitStructure.TIM_LOCKLevel=TIM_LOCKLevel_OFF;
TIM_BDTRInitStructure.TIM_OSSRState=TIM_OSSRState_Enable;
TIM_BDTRInitStructure.TIM_OSSIState=TIM_OSSIState_Enable;
TIM_BDTRConfig(TIM1,&TIM_BDTRInitStructure);
5.5.2 spwm波表选择
这里我们可以简单的用c语言代码生成对应点数值，生成SPWM波表
float sin_value[672]=
{0.500000,0.504207,0.508415,0.512621,0.516826,0.521030,0.525232,0.529431,
0.533629,0.537823,0.542014,0.546201,0.550384,0.554563,0.558737,0.562906,
0.567069,0.571227,0.575378,0.579522,0.583660,0.587791,0.591913,0.596028,
0.600134,0.604232,0.608320,0.612399,0.616469,0.620528,0.624576,0.628614,
0.632640,0.636655,0.640657,0.644648,0.648626,0.652590,0.656542,0.660480,
0.664403,0.668313,0.672208,0.676087,0.679951,0.683800,0.687632,0.691448,
0.695248,0.699030,0.702795,0.706542,0.710271,0.713982,0.717673,0.721346,
0.725000,0.728634,0.732248,0.735841,
... ... ...
0.304752,0.308552,0.312368,0.316200,0.320049,0.323913,0.327792,0.331687,
0.335597,0.339520,0.343458,0.347410,0.351374,0.355352,0.359343,0.363345,
0.367360,0.371386,0.375424,0.379472,0.383531,0.387601,0.391680,0.395768,
0.399866,0.403972,0.408087,0.412209,0.416340,0.420477,0.424622,0.428773,
0.432931,0.437094,0.441263,0.445437,0.449616,0.453799,0.457986,0.462177,
0.466371,0.470569,0.474768,0.478970,0.483174,0.487379,0.491585,0.495793};
5.5.3 spwm中断程序
void TIM1_UP_TIM10_IRQHandler(void)
{
if(TIM_GetITStatus(TIM1,TIM_IT_Update)==SET)
{
spwm_duty = 1000*sin_value[cnt++];
if(cnt == 672)
cnt = 0;
TIM_SetCompare1(TIM1,spwm_duty);
}
TIM_ClearITPendingBit(TIM1,TIM_IT_Update);
}
实验现象图
史海拾趣
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