STM32单片机PWM输出一直是高电平,怎么解决?

ID:42292 · 发表于 2023-9-2 15:18

1、单片机：STM32L031G6U6
2、使用IO:PA6 TIM22 CH1 PA7 TIM22 CH2
3、时钟配置：1.048M
TIM22配置频率：晶振频率1.048Mhz  预分频系数为 0，自动重装载值为 99，定时器溢出频率，即PWM的周期，就是 1.048MHz/(0+1)/(99+1) = 10.048kHz
4、问题：不能输出PWM波形，示波器测试的

使能时输出高电平，不使能时输出低电平
HAL_TIM_PWM_Start(&htim22,TIM_CHANNEL_1);  //开启PWM输出
HAL_TIM_PWM_Start(&htim22,TIM_CHANNEL_2);  //开启PWM输出

TIM22初始化的代码

static void MX_TIM22_Init(void)
{
/* USER CODE BEGIN TIM22_Init 0 */
__HAL_RCC_TIM22_CLK_ENABLE();
/* USER CODE END TIM22_Init 0 */
__HAL_RCC_TIM22_CLK_ENABLE();
TIM_ClockConfigTypeDef sClockSourceConfig = {0};
TIM_MasterConfigTypeDef sMasterConfig = {0};
TIM_OC_InitTypeDef sConfigOC = {0};
/* USER CODE BEGIN TIM22_Init 1 */
/* USER CODE END TIM22_Init 1 */
htim22.Instance = TIM22;
htim22.Init.Prescaler = 0;//晶振频率1.048Mhz 预分频系数为 0，自动重装载值为 99，定时器溢出频率，即PWM的周期，就是 1.048MHz/(0+1)/(99+1) = 10.048kHz
htim22.Init.CounterMode = TIM_COUNTERMODE_UP;
htim22.Init.Period = 99;
htim22.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
htim22.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;//自动重装载
if (HAL_TIM_Base_Init(&htim22) != HAL_OK)
{
Error_Handler();
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
if (HAL_TIM_ConfigClockSource(&htim22, &sClockSourceConfig) != HAL_OK)
{
Error_Handler();
}
if (HAL_TIM_PWM_Init(&htim22) != HAL_OK)
{
Error_Handler();
}
if (HAL_TIM_OnePulse_Init(&htim22, TIM_OPMODE_SINGLE) != HAL_OK)
{
Error_Handler();
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim22, &sMasterConfig) != HAL_OK)
{
Error_Handler();
}
sConfigOC.OCMode = TIM_OCMODE_PWM1;// PWM模式1
sConfigOC.Pulse = 60;//初始化占空比
sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;//当定时器计数值小于CCR1_Val时为高电平*/
sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
if (HAL_TIM_PWM_ConfigChannel(&htim22, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
{
Error_Handler();
}
if (HAL_TIM_PWM_ConfigChannel(&htim22, &sConfigOC, TIM_CHANNEL_2) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN TIM22_Init 2 */
/* USER CODE END TIM22_Init 2 */
__HAL_RCC_GPIOA_CLK_ENABLE();
/**TIM22 GPIO Configuration
PA6 ------> TIM22_CH1
PA7 ------> TIM22_CH2
*/
GPIO_InitTypeDef GPIO_InitStruct = {0};
GPIO_InitStruct.Pin = GPIO_PIN_6|GPIO_PIN_7;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF5_TIM22;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
HAL_TIM_PWM_Start(&htim22,TIM_CHANNEL_1); //开启PWM输出
//HAL_TIM_PWM_Start(&htim22,TIM_CHANNEL_2); //开启PWM输出
__HAL_TIM_SET_COMPARE(&htim22,TIM_CHANNEL_1,50); //设置默认的占空比值
//__HAL_TIM_SET_COMPARE(&htim22,TIM_CHANNEL_2,50); //设置默认的占空比值
}

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主函数调用初始化

int main(void)
{
static U8 LedTimer;
U8 temp;
HAL_Init();
SystemClock_Config();
MX_ADC_Init();
MX_GPIO_Init();
MX_TIM2_Init();
MX_TIM21_Init();
MX_TIM22_Init();

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主循环中持续输出：

while (1)
{
__HAL_TIM_SET_COMPARE(&htim22,TIM_CHANNEL_1,50); //设置默认的占空比值
led_blink();

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