实现功能:单片机以一定的采样频率(如2Khz)进行采样,例如每分钟(60s)只采前30s,后30s休眠(定时休眠唤醒),等到下一分钟再自动wakeup,如此循环30分钟。30分钟之后,单片机进入休眠stop模式。用串口中断的方式将休眠的单片机唤醒。
实现方法:
1、定时休眠唤醒code
HAL_Delay(2000);//进行采样的时间
HAL_RTCEx_DeactivateWakeUpTimer(&RTCHandle);
HAL_RTCEx_SetWakeUpTimer_IT(&RTCHandle, 2, RTC_WAKEUPCLOCK_RTCCLK_DIV16);
HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFI);//调用库函数进入STOP模式
SystemClockConfig_STOP();//停机模式后唤醒,恢复时钟源
count1++;
while(count1==1)//循环的次数
{
Rx_Init();
count1=0;
flag3=0;
__HAL_RTC_ALARM_DISABLE_IT(&RTCHandle, RTC_IT_ALRA);
__HAL_RTC_ALARM_CLEAR_FLAG(&RTCHandle, RTC_IT_ALRA);
HAL_TIM_Base_Stop(&TimHandle); //定时器停止
HAL_RTCEx_DeactivateWakeUpTimer(&RTCHandle);
HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFI);//调用库函数进入STOP模式
}
计算方法:例如休眠4s
/* RTC Wakeup Interrupt Generation:
Wakeup Time Base = (RTC_WAKEUPCLOCK_RTCCLK_DIV /(LSE or LSI))
Wakeup Time = Wakeup Time Base * WakeUpCounter
= (RTC_WAKEUPCLOCK_RTCCLK_DIV /(LSE or LSI)) * WakeUpCounter
==> WakeUpCounter = Wakeup Time / Wakeup Time BaseTo configure the wake up timer to 4s the WakeUpCounter is set to 0x1FFF:
RTC_WAKEUPCLOCK_RTCCLK_DIV = RTCCLK_Div16 = 16
Wakeup Time Base = 16 /(~39.000KHz) = ~0,410 ms
Wakeup Time = ~4s = 0,410ms * WakeUpCounter
==> WakeUpCounter = ~4s/0,410ms = 9750 = 0x2616 */
HAL_RTCEx_SetWakeUpTimer_IT(&RTCHandle, 0x2616, RTC_WAKEUPCLOCK_RTCCLK_DIV16);
局限性:用内部时钟LSI,大小固定导致Wakeup Time Base 被限制。 Wakeup Time(最大)=0.41ms*65535(0xffff)=26.869s,可能达不到休眠时间要求。
另一种方法:改HAL_RTCEx_SetWakeUpTimer_IT(&RTCHandle, 2, RTC_WAKEUPCLOCK_CK_SPRE_16BITS);
这里RTC_WAKEUPCLOCK_CK_SPRE_16BITS是设置CR寄存器中的低三位,唤醒时钟选择,这里选择1hz,2表示工作2S后进入唤醒中断,这个数随便改,改成多少就是休眠多少时间。
2、串口中断唤醒
唤醒机制:在MCU进入STOP状态后,不能直接通过UART等外设唤醒,在MCU进入STOP前将RX脚设为EXTI模式,并使能对应的中断。唤醒后重新初始化串口、配置时钟。(这里贴两份代码,一份是我参考的百战天虫的code,另一份我自己的)
扫描二维码关注公众号,回复:
3763527 查看本文章
![](/qrcode.jpg)
by:百战天虫
void Rx_Init()
{
GPIO_InitTypeDef GPIO_InitStruct;
__HAL_RCC_GPIOA_CLK_ENABLE();
// 配置UART1的Rx引脚为EXIT模式
GPIO_InitStruct.Pin = USARTx_RX_PIN;
GPIO_InitStruct.Mode = GPIO_MODE_IT_FALLING; // 特别注意这里要使用中断模式
GPIO_InitStruct.Pull = GPIO_PULLUP;
HAL_GPIO_Init(USARTx_TX_GPIO_PORT, &GPIO_InitStruct);
HAL_NVIC_SetPriority(EXTI4_15_IRQn, 2, 0);
HAL_NVIC_EnableIRQ(EXTI4_15_IRQn);
}
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
if(GPIO_Pin==USARTx_RX_PIN)
{
// HAL_NVIC_EnableIRQ(SysTick_IRQn);
SystemClockConfig_STOP();//停机模式后唤醒,恢复时钟源
HAL_Init();
SystemClock_Config();
SystemPower_Config();
HAL_SPI_DeInit(&hspi1);
HAL_GPIO_DeInit(GPIOA,GPIO_PIN_10);//串口重新初始化时HAL_UART_Init()函数会判断if(huart->State == HAL_UART_STATE_RESET),此时才会执行HAL_UART_MspInit(huart),配置串口IO口,这句话必须有!
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
SPI_GPIO_Init();
UartHandle.Instance = USARTx;
UartHandle.Init.BaudRate = uart_baud;
UartHandle.Init.WordLength = UART_WORDLENGTH_8B;
UartHandle.Init.StopBits = UART_STOPBITS_1;
UartHandle.Init.Parity = UART_PARITY_NONE;
UartHandle.Init.HwFlowCtl = UART_HWCONTROL_NONE;
UartHandle.Init.Mode = UART_MODE_TX_RX;
GPIO_InitTypeDef GPIO_InitStruct;
/*##-1- Enable peripherals and GPIO Clocks #################################*/
/* Enable GPIO TX/RX clock */
USARTx_TX_GPIO_CLK_ENABLE();
USARTx_RX_GPIO_CLK_ENABLE();
/* Enable USART2 clock */
USARTx_CLK_ENABLE();
/*##-2- Configure peripheral GPIO ##########################################*/
/* UART TX GPIO pin configuration */
GPIO_InitStruct.Pin = USARTx_TX_PIN;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH ;
GPIO_InitStruct.Alternate = USARTx_TX_AF;
HAL_GPIO_Init(USARTx_TX_GPIO_PORT, &GPIO_InitStruct);
/* UART RX GPIO pin configuration */
GPIO_InitStruct.Pin = USARTx_RX_PIN;
GPIO_InitStruct.Alternate = USARTx_RX_AF;
HAL_GPIO_Init(USARTx_RX_GPIO_PORT, &GPIO_InitStruct);
HAL_NVIC_DisableIRQ(EXTI4_15_IRQn);
__HAL_GPIO_EXTI_CLEAR_IT(USARTx_RX_PIN);
HAL_NVIC_SetPriority(USARTx_IRQn, 4, 0);
HAL_NVIC_EnableIRQ(USARTx_IRQn);
}
}
结束!
最后贴上硬石的按键唤醒,很有参考价值!