Count External Clock pulses
Hi Team,
Currently I am working with STM32U575ZiTx SOC and I am using Tim3 for counting external clock pulses,
Can you guide me with the code please.
Below is my requirement :
1. What is the maximum frequency of the incoming signal? (To ensure the timer can handle it without missing counts)
Answer : The frequency is measuring the spin rate of a physical system; a wind-turbine RPM or something similar.
I think we can very safely say the maximum edge rate will be less than 100 kHz (heh) and probably closer to a max of 3600.
2. Should the rolling counter value be transmitted as-is, or should it be reset after each transmission?
Answer : We confirmed with the end customer that the counter will roll over and is expected to reset on reboot.
Code Reference :
static void MX_TIM3_Init(void)
{
/* USER CODE BEGIN TIM3_Init 0 */
/* USER CODE END TIM3_Init 0 */
TIM_ClockConfigTypeDef sClockSourceConfig = {0};
TIM_MasterConfigTypeDef sMasterConfig = {0};
TIM_IC_InitTypeDef sConfigIC = {0};
/* USER CODE BEGIN TIM3_Init 1 */
/* USER CODE END TIM3_Init 1 */
htim3.Instance = TIM3;
htim3.Init.Prescaler = 0;
htim3.Init.CounterMode = TIM_COUNTERMODE_UP;
htim3.Init.Period = 4294967295;
htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV2;
htim3.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
if (HAL_TIM_Base_Init(&htim3) != HAL_OK)
{
Error_Handler();
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_ETRMODE2;
sClockSourceConfig.ClockPolarity = TIM_CLOCKPOLARITY_NONINVERTED;
sClockSourceConfig.ClockPrescaler = TIM_CLOCKPRESCALER_DIV1;
sClockSourceConfig.ClockFilter = 0;
if (HAL_TIM_ConfigClockSource(&htim3, &sClockSourceConfig) != HAL_OK)
{
Error_Handler();
}
if (HAL_TIM_IC_Init(&htim3) != HAL_OK)
{
Error_Handler();
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim3, &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(&htim3, &sConfigIC, TIM_CHANNEL_1) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN TIM3_Init 2 */
/* USER CODE END TIM3_Init 2 */
}
void Timer_Handling_Thread(void *argument)
{
char iridium_buffer[64] = {0};
HAL_TIM_Base_Start(&htim3);
while(1)
{
uint32_t count = __HAL_TIM_GET_COUNTER(&htim3);
snprintf(iridium_buffer, sizeof(iridium_buffer),"Pulse Count: %lu (dec), 0x%lX (hex)\r\n", count, count);
HAL_UART_Transmit(&huart2, (uint8_t *)iridium_buffer, strlen(iridium_buffer), HAL_MAX_DELAY);
}
}
Can you help me with respect to the configurations of CubeMX ? If possible please provide a suggestions on this post ?