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65 lines
1.7 KiB
65 lines
1.7 KiB
#include <Arduino.h>
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static TIM_HandleTypeDef s_TimerInstance = {0};
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typedef void (*timer_callback_t)(void);
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timer_callback_t timer_callback = NULL;
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#define ATOMIC(X) noInterrupts(); X; interrupts();
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// forward declaration of ISR
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void uclockISR();
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void timer_attachInterrupt(TIM_TypeDef *tim, uint32_t microseconds, timer_callback_t callback)
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{
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// Enable timer clock
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if (tim == TIM2) __HAL_RCC_TIM2_CLK_ENABLE();
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else if (tim == TIM3) __HAL_RCC_TIM3_CLK_ENABLE();
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else if (tim == TIM4) __HAL_RCC_TIM4_CLK_ENABLE();
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// Calculate the prescaler value
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uint32_t prescaler = (SystemCoreClock / 1000000UL) - 1;
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// Calculate the period value
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uint32_t period = (microseconds * 2UL) - 1UL;
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// Set up the timer instance
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s_TimerInstance.Instance = tim;
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s_TimerInstance.Init.Prescaler = prescaler;
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s_TimerInstance.Init.CounterMode = TIM_COUNTERMODE_UP;
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s_TimerInstance.Init.Period = period;
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s_TimerInstance.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
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// Configure the timer instance
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HAL_TIM_Base_Init(&s_TimerInstance);
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HAL_TIM_Base_Start_IT(&s_TimerInstance);
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// Save the callback function
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timer_callback = callback;
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}
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void TIM2_IRQHandler()
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{
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// Call the callback function
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timer_callback();
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// Clear the interrupt flag
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__HAL_TIM_CLEAR_FLAG(&s_TimerInstance, TIM_FLAG_UPDATE);
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}
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void initTimer(uint32_t us_interval)
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{
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// Set up the timer to call the callback function every us_interval microseconds
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timer_attachInterrupt(TIM2, us_interval, uclockISR);
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}
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void setTimer(uint32_t us_interval)
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{
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// Calculate the period value
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uint32_t period = (us_interval * 2UL) - 1UL;
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// Update the timer instance with the new period value
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s_TimerInstance.Init.Period = period;
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HAL_TIM_Base_Init(&s_TimerInstance);
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}
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