Using STM32F429ZIT6 - Nucleo
Here's what I observe on PE9. Counter Mode is upcounting, PWM Mode 2
At first, I thought there had conflicts in the parameters (OCMode, OCPolarity and OCIdleState) of MX_TIM1_Init() function
static void MX_TIM1_Init(void)
{
/* USER CODE BEGIN TIM1_Init 0 */
/* USER CODE END TIM1_Init 0 */
TIM_ClockConfigTypeDef sClockSourceConfig = {0};
TIM_SlaveConfigTypeDef sSlaveConfig = {0};
TIM_MasterConfigTypeDef sMasterConfig = {0};
TIM_OC_InitTypeDef sConfigOC = {0};
TIM_BreakDeadTimeConfigTypeDef sBreakDeadTimeConfig = {0};
/* USER CODE BEGIN TIM1_Init 1 */
/* USER CODE END TIM1_Init 1 */
htim1.Instance = TIM1;
htim1.Init.Prescaler = 0;
htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
htim1.Init.Period = 451;
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_PWM_Init(&htim1) != HAL_OK)
{
Error_Handler();
}
if (HAL_TIM_OnePulse_Init(&htim1, TIM_OPMODE_SINGLE) != HAL_OK)
{
Error_Handler();
}
sSlaveConfig.SlaveMode = TIM_SLAVEMODE_TRIGGER;
sSlaveConfig.InputTrigger = TIM_TS_ITR1;
if (HAL_TIM_SlaveConfigSynchro(&htim1, &sSlaveConfig) != HAL_OK)
{
Error_Handler();
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig) != HAL_OK)
{
Error_Handler();
}
sConfigOC.OCMode = TIM_OCMODE_PWM2;
sConfigOC.Pulse = 1;
sConfigOC.OCPolarity = TIM_OCPOLARITY_LOW;
sConfigOC.OCNPolarity = TIM_OCNPOLARITY_LOW;
sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
sConfigOC.OCIdleState = TIM_OCIDLESTATE_SET;
sConfigOC.OCNIdleState = TIM_OCIDLESTATE_SET;
if (HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
{
Error_Handler();
}
sBreakDeadTimeConfig.OffStateRunMode = TIM_OSSR_DISABLE;
sBreakDeadTimeConfig.OffStateIDLEMode = TIM_OSSI_DISABLE;
sBreakDeadTimeConfig.LockLevel = TIM_LOCKLEVEL_OFF;
sBreakDeadTimeConfig.DeadTime = 0;
sBreakDeadTimeConfig.BreakState = TIM_BREAK_DISABLE;
sBreakDeadTimeConfig.BreakPolarity = TIM_BREAKPOLARITY_HIGH;
sBreakDeadTimeConfig.AutomaticOutput = TIM_AUTOMATICOUTPUT_DISABLE;
if (HAL_TIMEx_ConfigBreakDeadTime(&htim1, &sBreakDeadTimeConfig) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN TIM1_Init 2 */
// sConfigOC.OCMode = TIM_OCMODE_PWM1; //Actice High trigger pulse
// sConfigOC.OCMode = TIM_OCMODE_PWM2; //Actice Low trigger pulse
//TIM1 Clock input is 180 MHz, period = 5.555 ns
//TIM1_CCR1 = 1 (sConfigOC.Pulse = 1;)
//TIM1_ARR = 451 (htim1.Init.Period = 451;)
//Delay to generate pulse = 1 * 5.555 ns = 5.555ns
//Pulse width = (451-1)*5.555ns = 2.5 us
/* USER CODE END TIM1_Init 2 */
HAL_TIM_MspPostInit(&htim1);
}But after checking documentation, I think thoses are fine!?
Not sure what is causing the issue, any Ideas ?
If you need whole main.c, don't hesitate to ask.
This was observed on STM32F429ZIT6 - Nucleo board which should be a "known good" board.
My oscilloscope has sampling probe on a wire going in D6 (PE9) and reference probe on GND Pin 5 of CN10. I dont think its improper ground.
Do you mean electromagnetic interference ? I dont see any source around me that could generate this frequency.
I poked 3V3 line on CN8 Pin 7 and 5V line CN8 Pin 9 and here's what I observed ;
3V3 CN8 Pin 7
5V CN8 Pin 9 
Maybe I damaged the on board regulator or filtering capacitor on power lines with an ESD ?
I poked U5V on R12 that is the 5V source coming from my USB port
and I observed the same ripples. It looks like that is root cause and the solution would be to have a cleaner (less ripples) power source.
