hii sir ,as per youre suggestion i implement my code.
#include "stm32l4xx_hal.h"
// Global variables
volatile uint32_t t1 = 0, t2 = 0; // Captured timer values
volatile float duty_c = 0; // Calculated duty cycle
volatile uint32_t timeout_flag = 0; // Timeout flag
uint32_t timeout_threshold_ms = 500; // Timeout threshold in milliseconds
TIM_HandleTypeDef htim2; // Timer 2 handle
// Function prototypes
void SystemClock_Config(void);
void Error_Handler(void);
void TIM2_Init(void);
void handle_signal_loss(void);
int main(void) {
HAL_Init();
SystemClock_Config();
// Initialize Timer 2 for input capture
TIM2_Init();
// Start input capture for both channels
HAL_TIM_IC_Start_IT(&htim2, TIM_CHANNEL_1); // Rising edge
HAL_TIM_IC_Start_IT(&htim2, TIM_CHANNEL_2); // Falling edge
while (1) {
if (timeout_flag) {
timeout_flag = 0; // Reset the flag
handle_signal_loss();
}
// Main application logic
}
}
// Timer 2 initialization
void TIM2_Init(void) {
__HAL_RCC_TIM2_CLK_ENABLE();
TIM_IC_InitTypeDef sConfigIC;
htim2.Instance = TIM2;
htim2.Init.Prescaler = 79; // Timer clock = 1 MHz (assuming 80 MHz system clock)
htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
htim2.Init.Period = 0xFFFF; // Maximum count value
htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
HAL_TIM_IC_Init(&htim2);
// Configure Channel 1 for rising edge detection
sConfigIC.ICPolarity = TIM_ICPOLARITY_RISING;
sConfigIC.ICSelection = TIM_ICSELECTION_DIRECTTI;
sConfigIC.ICPrescaler = TIM_ICPSC_DIV1;
sConfigIC.ICFilter = 0;
HAL_TIM_IC_ConfigChannel(&htim2, &sConfigIC, TIM_CHANNEL_1);
// Configure Channel 2 for falling edge detection
sConfigIC.ICPolarity = TIM_ICPOLARITY_FALLING;
HAL_TIM_IC_ConfigChannel(&htim2, &sConfigIC, TIM_CHANNEL_2);
}
// Input capture callback
void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim) {
static uint32_t last_edge_time = 0;
if (htim->Instance == TIM2) {
if (htim->Channel == HAL_TIM_ACTIVE_CHANNEL_1) {
// Rising edge captured: Period start
t1 = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_1);
if (t1 != 0) {
t2 = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_2); // Falling edge captured
duty_c = ((float)t2 / t1) * 100.0; // Calculate duty cycle
// Reset the timeout mechanism
__HAL_TIM_SET_COUNTER(&htim2, 0);
timeout_flag = 0;
last_edge_time = HAL_GetTick(); // Update last active time
}
}
}
}
// Timer overflow callback (timeout detection)
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim) {
if (htim->Instance == TIM2) {
// Check for timeout condition
if ((HAL_GetTick() - last_edge_time) > timeout_threshold_ms) {
timeout_flag = 1; // Set the timeout flag
}
}
}
// Handle signal loss
void handle_signal_loss(void) {
printf("Signal lost! Timeout occurred.\n");
// Handle signal loss condition here (e.g., reset variables, trigger an error state)
duty_c = 0;
}
// System clock configuration (implement as needed for your MCU)
void SystemClock_Config(void) {
// Configure system clock here (use CubeMX for guidance)
}
// Error handler
void Error_Handler(void) {
while (1) {
// Stay here for debugging
}
}
sir but still it not work.as per my knowledge for the measurement of duty cycle we totally relies on capture callback function ,and this function only trigger when edge is detected in input. For 0 and 100% duty cycle there are no edges therefore this function never activated and measure the duty cycle. I guess when we gives 0% or 100% duty cycle mcu go in hang mode therefore it is not able to measure 0% or 100% duty cycle. suggest any other solution sir.
Thankyou.
