STM32如何使用定时器做分频器？

lindaoyou · 发表于 2020-5-26 08:48:55

想使用STM32F4的定时器做一个2分频的分频器:要求从某个定时器的通道1引脚输入一个特定的频率（100KHz）,从该定时器的通道4引脚输出50KHz的频率。该如何实现。从网上看了一下代码配置使用无法成功实现（以下会贴出有误代码）。还有就是有人建议使用STM32CubeMX配置，但是配置后使用的是HAL库，不会用。而且我下载的STM32CubeMX无法生成工程代码。以下程序配置有哪里不对，请大神指点

void TIM8_PWM_Init(u32 arr,u32 psc)
{
//此部分需手动修改IO口设置
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM8,ENABLE);    //TIM8时钟使能
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE); //使能PORTC时钟

GPIO_PinAFConfig(GPIOC,GPIO_PinSource9,GPIO_AF_TIM8); //GPIOC9复用为定时器8

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 ; /*CH1 */
GPIO_Init(GPIOC, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;    //推挽复用输出
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;       //上拉
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; /* CH4 */
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOC, &GPIO_InitStructure);

TIM_DeInit(TIM8);
TIM_TimeBaseStructure.TIM_Period = 2-1; //-计数是从0开始的，所以减1 TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM8, &TIM_TimeBaseStructure);
TIM_TIxExternalClockConfig(TIM8,TIM_TIxExternalCLK1Source_TI1ED,
TIM_ICPolarity_Rising,0);
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 2-1; //-计数是从0开始的，所以减1
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
/* Output Compare Toggle Mode configuration: Channel4 */
TIM_OC4Init(TIM8, &TIM_OCInitStructure);
TIM_OC4PreloadConfig(TIM8, TIM_OCPreload_Disable);
TIM_SetCounter(TIM8, 0);
TIM_ARRPreloadConfig(TIM8, ENABLE);
TIM_Cmd(TIM8, ENABLE);
TIM_CtrlPWMOutputs(TIM8, ENABLE);
}