[英]STM32 Blinking LEDs with a Timer
我正在嘗試使用計時器中斷以不同的頻率閃爍4個LED。
我想出了這段代碼
/*********** Includes ****************/
#include "stm32f4xx.h"
#include "stm32f4_discovery.h"
/*********** Defines *****************/
#define TIM3_CK_CNT 50000
/*********** Declarations *************/
/*------ Function prototypes ---------*/
void TimerConfiguration(void);
/* ----- Global variables ----------- */
volatile uint16_t CCR1_Val = 50000;
volatile uint16_t CCR2_Val = 40000;
volatile uint16_t CCR3_Val = 30000;
volatile uint16_t CCR4_Val = 20000;
/************ Main *********************/
int main(void)
{
// LED initialization
STM_EVAL_LEDInit(LED3); // Orange
STM_EVAL_LEDInit(LED4); // Green
STM_EVAL_LEDInit(LED5); // Red
STM_EVAL_LEDInit(LED6); // Blue
/* TIM3 Configuration */
TimerConfiguration();
while (1);
}
/*********** Functions *****************/
/**
* @brief Configure the TIM3 TIMER.
* @param None
* @retval None
*/
void TimerConfiguration(void)
{
uint16_t PrescalerValue = 0;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
/* TIM3 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 65535;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
/* Prescaler configuration */
PrescalerValue = (uint16_t) ((SystemCoreClock / 2) / TIM3_CK_CNT) - 1;
TIM_PrescalerConfig(TIM3, PrescalerValue, TIM_PSCReloadMode_Immediate);
/* Output Compare Timing Mode configuration: Channel1 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Timing;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR1_Val;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM3, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Disable);
/*Channel2 */
TIM_OCInitStructure.TIM_Pulse = CCR2_Val;
TIM_OC2Init(TIM3, &TIM_OCInitStructure);
/*Channel3 */
TIM_OCInitStructure.TIM_Pulse = CCR3_Val;
TIM_OC3Init(TIM3, &TIM_OCInitStructure);
/*Channel4 */
TIM_OCInitStructure.TIM_Pulse = CCR4_Val;
TIM_OC4Init(TIM3, &TIM_OCInitStructure);
/* Configure the TIM3 gloabal Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
/* TIM Interrupts enable */
TIM_ITConfig(TIM3, TIM_IT_CC1, ENABLE);
TIM_ITConfig(TIM3, TIM_IT_CC2, ENABLE);
TIM_ITConfig(TIM3, TIM_IT_CC3, ENABLE);
TIM_ITConfig(TIM3, TIM_IT_CC4, ENABLE);
/* TIM3 counter enable */
TIM_Cmd(TIM3, ENABLE);
}
int LedCount6 = 0;
int LedCount5 = 0;
int LedCount4 = 0;
int LedCount3 = 0;
/************ Interrupt Handlers *************/
/**
* @brief This function handles TIM3 global interrupt request.
* @param None
* @retval None
*/
void TIM3_IRQHandler(void)
{
uint16_t capture = 0;
LedCount6++;
LedCount5++;
LedCount4++;
LedCount3++;
if ((TIM_GetITStatus(TIM3, TIM_IT_CC2) != RESET) && (TIM_GetITStatus(TIM3, TIM_IT_CC1) != RESET) && (TIM_GetITStatus(TIM3, TIM_IT_CC3) != RESET) && (TIM_GetITStatus(TIM3, TIM_IT_CC4) != RESET))
{
TIM_ClearITPendingBit(TIM3, TIM_IT_CC1);
TIM_ClearITPendingBit(TIM3, TIM_IT_CC2);
TIM_ClearITPendingBit(TIM3, TIM_IT_CC3);
TIM_ClearITPendingBit(TIM3, TIM_IT_CC4);
int val6 = 100000;
int val5 = 70000;
int val4 = 60000;
int val3 = 50000;
if (LedCount6 >= val6 ) {
/* LED6 toggling */
STM_EVAL_LEDToggle(LED6);
LedCount6 = 0;
/* Update CH1 OCR */
capture = TIM_GetCapture1(TIM3);
TIM_SetCompare1(TIM3, capture + CCR1_Val);}
if (LedCount5 >= val5) {
/* LED5 toggling */
STM_EVAL_LEDToggle(LED5);
LedCount5 = 0;
/* Update CH2 OCR */
capture = TIM_GetCapture2(TIM3);
TIM_SetCompare2(TIM3, capture + CCR2_Val);}
if (LedCount4 >= val4) {
/* LED4 toggling */
STM_EVAL_LEDToggle(LED4);
LedCount4 = 0;
/* Update CH3 OCR */
capture = TIM_GetCapture3(TIM3);
TIM_SetCompare3(TIM3, capture + CCR3_Val);}
if (LedCount3 >= val3 ) {
/* LED3 toggling */
STM_EVAL_LEDToggle(LED3);
LedCount3 = 0;
/* Update CH4 OCR */
capture = TIM_GetCapture4(TIM3);
TIM_SetCompare4(TIM3, capture + CCR4_Val);}
}
}
現在,所有使4個LED閃爍的代碼都在中斷處理程序內(void TIM3_IRQHandler(void))。 4個LED閃爍,但同時全部閃爍,如何更改它們的頻率以使其完全不同?
更改TIM3_CK_CNT值將更改所有4的頻率,但是由於這是一個定義,因此我無法通過代碼來操縱它以更改每個led的頻率。
TIMER(TIM3)有4個通道,所有通道均可引起中斷,但所有通道的中斷處理程序都相同。
像這樣替換您的IRQ處理程序(根據需要更改LED切換開關):
void TIM3_IRQHandler(void)
{
uint16_t capture = 0;
if (TIM_GetITStatus(TIM3, TIM_IT_CC2) != RESET)
{
TIM_ClearITPendingBit(TIM3, TIM_IT_CC2);
/* LED6 toggling */
STM_EVAL_LEDToggle(LED6);
/* Update CH1 OCR */
capture = TIM_GetCapture1(TIM3);
TIM_SetCompare1(TIM3, capture + CCR1_Val);
}
else if (TIM_GetITStatus(TIM3, TIM_IT_CC1) != RESET)
{
TIM_ClearITPendingBit(TIM3, TIM_IT_CC1);
/* LED5 toggling */
STM_EVAL_LEDToggle(LED5);
/* Update CH2 OCR */
capture = TIM_GetCapture2(TIM3);
TIM_SetCompare2(TIM3, capture + CCR2_Val);
}
else if (TIM_GetITStatus(TIM3, TIM_IT_CC3) != RESET)
{
TIM_ClearITPendingBit(TIM3, TIM_IT_CC3);
/* LED4 toggling */
STM_EVAL_LEDToggle(LED4);
/* Update CH3 OCR */
capture = TIM_GetCapture3(TIM3);
TIM_SetCompare3(TIM3, capture + CCR3_Val);
}
else if (TIM_GetITStatus(TIM3, TIM_IT_CC4) != RESET)
{
TIM_ClearITPendingBit(TIM3, TIM_IT_CC4);
/* LED3 toggling */
STM_EVAL_LEDToggle(LED3);
/* Update CH4 OCR */
capture = TIM_GetCapture4(TIM3);
TIM_SetCompare4(TIM3, capture + CCR4_Val);
}
}
進行此更改后,LED將針對每個通道中斷進行切換。 即每個中斷只有一個LED閃爍。 為了以不同的頻率閃爍,您需要查看數據表,如何為不同的LED通道配置不同的頻率。
代碼太大,無法在此處放置。
這是我的解決方案: https : //www.diymat.co.uk/arm-blinking-led-driver/
任何數量的LED,任何頻率(關閉和打開時間可以不同),任何數量的閃爍(+連續)和序列結束時的回調。
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