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【原創】編程輸出可調的硬件PWM，頻率范圍1Hz-1MHz，占空比0-100%
uint32_t TIM4_PWM_FQ = 50; /* TIM4_CH1_PWM輸出 頻率設置值，1-1000000 */
uint32_t TIM4_PWM_FQ_Old = 0;
uint16_t TIM4_PWM_Pulse = 50; /* TIM4_CH1_PWM輸出 占空比設置值，0-100 */
uint16_t TIM4_PWM_Pulse_Old = 0;
uint32_t SystemCoreClock = 168000000;
/*
* 函數功能: 定時器4配置為硬件PWM模式(不開啟TIM4的定時及DMA傳輸中斷)
* TIM4_PWM_FQ: TIM4_CH1_PWM 頻率 1Hz至1000000Hz
* TIM4_PWM_Pulse: TIM4_CH1_PWM 占空比 0-100%
*/
void StdPeriph_TIM4_PWM_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
uint32_t temp32;
uint32_t uhTimerfrequency;
uint16_t uhTimerPeriod;
uint16_t uhTimerPulse;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
#ifdef USE_PB6_PWM
// TIM4_CH1_PWM: PB6
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
// GPIOB Configuration
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_DOWN;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_Init(GPIOB, &GPIO_InitStruct);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_TIM4);
#else
// TIM4_CH1_PWM: PD12
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);
// GPIOD Configuration
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_Init(GPIOD, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOD, GPIO_PinSource12, GPIO_AF_TIM4);
#endif
uhTimerfrequency = 200000; /* 初始化 200KHz */
temp32 = ((SystemCoreClock /2) / uhTimerfrequency);
if(temp32 > 65535) temp32 = 65535;
uhTimerPeriod = (uint16_t) temp32;
uhTimerPulse = uhTimerPeriod * 50 / 100; /* 占空比50% */
// Time base configuration
TIM_TimeBaseStructure.TIM_Period = uhTimerPeriod - 1; /* 0x0000 and 0xFFFF */
TIM_TimeBaseStructure.TIM_Prescaler = 0; /* 0x0000 and 0xFFFF */
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);
// PWM1 Mode configuration: Channel1
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = uhTimerPulse;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OC1Init(TIM4, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM4, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM4, ENABLE);
TIM_GenerateEvent(TIM4, TIM_EventSource_Update);
TIM_Cmd(TIM4, ENABLE);
}
/*
* 函數功能: 刷新TIM4_CH1_PWM輸出的頻率和占空比
* 修改TIM4_PWM_FQ的值，調節PWM頻率(1Hz至1MHz)
* 修改TIM4_PWM_Pulse的值，調節PWM的占空比(0-100)
*/
void StdPeriph_TIM4_PWM_Update(void)
{
uint32_t temp32;
uint32_t uhTimerfrequency;
uint16_t uhTimerPeriod;
uint16_t uhTimerPrescaler;
uint16_t uhTimerPulse;
if ((TIM4_PWM_FQ_Old != TIM4_PWM_FQ) || (TIM4_PWM_Pulse_Old != TIM4_PWM_Pulse)){
TIM4_PWM_FQ_Old = TIM4_PWM_FQ;
TIM4_PWM_Pulse_Old = TIM4_PWM_Pulse;
if(TIM4_PWM_FQ >= 4000){
uhTimerfrequency = TIM4_PWM_FQ; /* 定時器計時頻率和PWM頻率相等 */
uhTimerPrescaler = 1; /* 實際頻率TIM4_PWM_FQ較大時，TIM4設置分頻為1(不分頻) */
}else{
uhTimerfrequency = 4000; /* 實際頻率TIM4_PWM_FQ較小時，和4000Hz的頻率比較，看相差幾倍 */
uhTimerPrescaler = 4000 / TIM4_PWM_FQ; /* 實際頻率和4000相差的倍數作為TIM4的分頻設置值 */
uhTimerfrequency = uhTimerPrescaler * TIM4_PWM_FQ; /* TIM4分頻后，計時周期變長，需要將uhTimerfrequency倍頻 */
}
/* TIM4的周期要通過倍頻uhTimerfrequency來計算,uhTimerPeriod = 84MHz / uhTimerfrequency */
temp32 = ((SystemCoreClock /2) / uhTimerfrequency);
if(temp32 > 65535) temp32 = 65535;
uhTimerPeriod = (uint16_t) temp32;
if(TIM4_PWM_Pulse > 100) TIM4_PWM_Pulse = 100;
uhTimerPulse = uhTimerPeriod * TIM4_PWM_Pulse/ 100;
TIM4->ARR = uhTimerPeriod - 1;
TIM4->PSC = uhTimerPrescaler - 1;
TIM4->CCR1 = uhTimerPulse;
TIM4->EGR = TIM_PSCReloadMode_Update;
}
}
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