Hi Guys,
STM32F103C8Tx, STM32CubeMx 4.26.1 with latest stm32f1 library.
I'm using the channel 1 of the timer3 to generate pwm to drive a LED, but after the timer is initialized, the gpio of the channel outputs low level which makes the LED brightened.
After the gpio working under PWM mode, there is no way to set the level of it, I have to turn on the pwm and set the CCR to maximum value to turn off the led.
I wonder is there any way to make the gpio ouput high level once the pwm initialized rather than modify my pcb?
Here is the initialization of the timer3 which was generated by the stm32cubemx.
void MX_TIM3_Init(void)
{
TIM_ClockConfigTypeDef sClockSourceConfig;
TIM_MasterConfigTypeDef sMasterConfig;
TIM_OC_InitTypeDef sConfigOC;
htim3.Instance = TIM3;
htim3.Init.Prescaler = 2812;
htim3.Init.CounterMode = TIM_COUNTERMODE_UP;
htim3.Init.Period = 255;
htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
htim3.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
if (HAL_TIM_Base_Init(&htim3) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
if (HAL_TIM_ConfigClockSource(&htim3, &sClockSourceConfig) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
if (HAL_TIM_PWM_Init(&htim3) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim3, &sMasterConfig) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
sConfigOC.OCMode = TIM_OCMODE_PWM1;
sConfigOC.Pulse = 0;
sConfigOC.OCPolarity = TIM_OCPOLARITY_LOW;
sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
if (HAL_TIM_PWM_ConfigChannel(&htim3, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
if (HAL_TIM_PWM_ConfigChannel(&htim3, &sConfigOC, TIM_CHANNEL_2) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
if (HAL_TIM_PWM_ConfigChannel(&htim3, &sConfigOC, TIM_CHANNEL_3) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
HAL_TIM_MspPostInit(&htim3);
}
After the method HAL_TIM_MspPostInit(&htim3) executed the LED was turned on immediately.
Here is the source code of the method HAL_TIM_MspPostInit(&htim3)
void HAL_TIM_MspPostInit(TIM_HandleTypeDef* timHandle)
{
GPIO_InitTypeDef GPIO_InitStruct;
if(timHandle->Instance==TIM3)
{
/* USER CODE BEGIN TIM3_MspPostInit 0 */
/* USER CODE END TIM3_MspPostInit 0 */
/**TIM3 GPIO Configuration
PA6 ------> TIM3_CH1
PA7 ------> TIM3_CH2
PB0 ------> TIM3_CH3
*/
GPIO_InitStruct.Pin = PWM_B_Pin|PWM_G_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
GPIO_InitStruct.Pin = PWM_R_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
HAL_GPIO_Init(PWM_R_GPIO_Port, &GPIO_InitStruct);
/* USER CODE BEGIN TIM3_MspPostInit 1 */
/* USER CODE END TIM3_MspPostInit 1 */
}
}
Thanks a lot!
