Question
timer output channel toggle mode
Hello,
I am using stm32f429zi for my project, I set timer 1 with 4 channels (channel 1 and 2 as input channel, and channel 3 is output channel). I would like to generate a pulse from channel 3 with low frequency and around 50% width to set a communication handshake signal to different control board. I set main frequency as 168MHz, so timer 1 APB2 is 168MHz. the setup is followed:
TIM_ClockConfigTypeDef sClockSourceConfig = {0};
TIM_MasterConfigTypeDef sMasterConfig = {0};
TIM_IC_InitTypeDef sConfigIC = {0};
TIM_OC_InitTypeDef sConfigOC = {0};
htim1.Instance = TIM1;
htim1.Init.Prescaler = 2099;
htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
htim1.Init.Period = 65535;
htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
htim1.Init.RepetitionCounter = 0;
htim1.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
if (HAL_TIM_Base_Init(&htim1) != HAL_OK)
{
Error_Handler();
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
if (HAL_TIM_ConfigClockSource(&htim1, &sClockSourceConfig) != HAL_OK)
{
Error_Handler();
}
if (HAL_TIM_IC_Init(&htim1) != HAL_OK)
{
Error_Handler();
}
if (HAL_TIM_OC_Init(&htim1) != HAL_OK)
{
Error_Handler();
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig) != HAL_OK)
{
Error_Handler();
}
sConfigIC.ICPolarity =TIM_INPUTCHANNELPOLARITY_RISING;
sConfigIC.ICSelection = TIM_ICSELECTION_DIRECTTI;
sConfigIC.ICPrescaler = TIM_ICPSC_DIV1;
sConfigIC.ICFilter = 0;
if (HAL_TIM_IC_ConfigChannel(&htim1, &sConfigIC, TIM_CHANNEL_1) != HAL_OK)
{
Error_Handler();
}
if (HAL_TIM_IC_ConfigChannel(&htim1, &sConfigIC, TIM_CHANNEL_4) != HAL_OK)
{
Error_Handler();
}
// sConfigIC.ICPolarity = TIM_INPUTCHANNELPOLARITY_FALLING;
// sConfigIC.ICSelection = TIM_ICSELECTION_INDIRECTTI;
// if (HAL_TIM_IC_ConfigChannel(&htim1, &sConfigIC, TIM_CHANNEL_2) != HAL_OK)
// {
// Error_Handler();
// }
sConfigOC.OCMode = TIM_OCMODE_TOGGLE;
sConfigOC.Pulse = 39999;
sConfigOC.OCPolarity =TIM_OCPOLARITY_LOW;// TIM_OCPOLARITY_LOW;
//sConfigOC.OCNPolarity = TIM_OCNPOLARITY_LOW;//TIM_OCNPOLARITY_HIGH;
sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
sConfigOC.OCIdleState = TIM_OCIDLESTATE_SET;
//sConfigOC.OCNIdleState = TIM_OCNIDLESTATE_RESET;
if (HAL_TIM_OC_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_3) != HAL_OK)
{
Error_Handler();
}
__HAL_TIM_MOE_ENABLE(&htim1);
HAL_TIM_MspPostInit(&htim1);However, after I start my program, I got the following result:
the pulse is not square pulse, the output voltage drops right away after comparator result trigger preset value and toggle output. Does anybody know how to fix this issue? Do I need use pulse output instead of toggle output mode.
thank you.
