運行主程序時如何在STM32f103xx上正確實現UART1中斷？

Question

我正在嘗試對我的 bluePill 進行編程以使 PB11 引腳上的 LED 閃爍，同時回顯通過串行端口 UART1 發送的內容。

據我所知，中斷允許我們運行我們想要的程序，並且在運行它時，如果任何標志觸發了中斷信號，程序控制將被轉移到在原始程序運行時運行中斷服務例程，我在這里是否正確?

所以，我試圖保持綠色 LED 閃爍，當我在串行端口上鍵入任何內容時，紅色 LED 閃爍，而綠色閃爍，藍色 LED 必須始終打開，除非正在發送數據。

問題 1：綠色 LED 從不閃爍！

問題 2：每當通過 Arduino 串行監視器發送字母或數字時，接收到的回聲始終是整個發送字母中的 2 個字母，而且回聲總是在同一行，我的意思是不在換行符上，所以輸入Hello並按 Enter 產生He和當在hi there並按 enter 時，它只會添加前兩個字母，例如Hehi ，為什么？

我的代碼是

/* ********************** Project Description ***********************
    STM32f103xx BluePill Board
    PB10 = Green LED
    PB11 = Blue LED (To be toggled)
    PB0 = Red LED (PWM OUTPUT Controlling the Brightness)
    PB9 = Push Button for toggling the state of the blue LED
    PA0 = Potentiomater Pin (Analog Input)
    USART1 Activated and Sends the Voltage of PA0 to the user1



*/


#include "stm32f1xx.h"  // Include the MCU header
#include <stdbool.h>    // Boolean Library header
#include <stdint.h>


// Prototypes:
void UART1_Init(void);              //Enable UART1 on PA9(Tx) & PA10(Rx).
void portsEnable(void);             //Enable Clock for desired MCU Ports.
void delay(uint32_t delay);         //Intuduce Delays.
void pinsConfig(void);              //Configure the used pins.


// Defines and Macros



int main(void)
{
  // Inintialization:
  portsEnable();
  pinsConfig();
  UART1_Init(); // Enable USART1 & interrupts @ 8Mhz clock Speed only @ 9600Bps

  while(1)
  {
    // ********  Blink The green LED ***********************
    GPIOB->BSRR = GPIO_BSRR_BS11;
    delay(100000);
    GPIOB->BSRR = GPIO_BSRR_BR11;
    delay(100000);

  } // End of while loop
} // End main() loop

// ************** Function Implimentation *****************************
void UART1_Init(void)                         // Initiallize USART1
{
  // Reset Setting (8bit, one stop bit, no parity)
  // Enable clock for UART1 First after already enabling the PortA clock
  RCC->APB2ENR |= RCC_APB2ENR_USART1EN;       // Enable Clock to the USART1 Module

  // Pin Configuration for the USART1 Peripheral where Tx(PA9) = AF Push-Pull and Rx = Input Floating
  
  // Setting Tx (PA9) Pin
  GPIOA->CRH |= ((1<<4) | (1<<5));      // Set PA9 to Output 50Mhz Mode
  GPIOA->CRH &= ~(1<<6);                // Configure it to be an AF push-pull
  GPIOA->CRH |= (1<<7);                 // Same as above^
  
  // Setting Rx (PA10) pin
  // Nothing to be set as the reset value makes it an input pin with floating configuration
  
  // Set the Baud-Rate
  USART1->BRR = 0x341;    //@ 8Mhz, USARTDIV = 8Mhz/(16*9600) = 52.083 -> 52=0x34 and 0.083 * 16 = 1.328 = 1 which is 0x1  

  // Enable Interrupts for the USART1 Module:
  // A peripheral can generates a flag at a certain event, this flag can trigger an interrupt signal but first the certain event interrupt must be enabled and the peripheral interrupt as well and the global interrupts.
  USART1->CR1 |= USART_CR1_TXEIE | USART_CR1_RXNEIE;    // Enable the Transmit Data Register Empty Interrupt register and data received interrupt

  // Enable the Tx, Rx, USART1 as a whole block
  USART1->CR1 |= (USART_CR1_RE | USART_CR1_TE | USART_CR1_UE);

  // Enable the USART1 Global interrupt on NVIC "Nested Vectored Interrupt controller" side. The NVIC is the interrupt processing unit in the MCU.
  NVIC_EnableIRQ(USART1_IRQn);  // This function's name can't be changed!
}
// This is a global interrupt service routine, any flag from the USART1 will lead to the same ISR, to distinguesh which is which we check the the flags and if one is set then this what caused the interrupt
void USART1_IRQHandler(void)                  // This function's name must be the same as it's defined in the main libraries
{
    // Check if we are here because we Received Data or simply the "RXNE flag is set".
    if(USART1->SR & USART_SR_RXNE)  // If Rx is Not Empty, or if we received Data, The USART1->SR register is going to change as it is controlled by the hardwart and we compare it to the value of the register USART_SR_RXNE which indicates a 1 at bit5
    {
      char temp = USART1->DR;  // Read the 8bit data received fron the data register into a char called temp
      USART1->DR = temp;       // Put the same data in the data register to be resent again, here the data registers are clled shadow registers they are not the same registers from the hardware prospective but from programming prospective we use the same registers
      
      while(!(USART1->SR & USART_SR_TC))
      {
        // Wait while the transmission completes and indicate the waiting process by flashing the RED led indicating data being sent.
        GPIOB->BSRR = GPIO_BSRR_BR10;      // When not ready to accept more data (e.g. while transmitting data process) turn of the Blue LED
        GPIOB->BSRR = GPIO_BSRR_BS1;
        delay(10000);
        GPIOB->BSRR = GPIO_BSRR_BR1;
      }

    } 

      // Check if we are here because the TXEIE is set "OR the Transmit complete" meaning we are ready to accept more data to transmit
      if(USART1->SR & USART_SR_TXE)
      {
        // Handle transmit complete here: (Blink an LED)
        GPIOB->BSRR = GPIO_BSRR_BS10;       // When Ready to accept more data
      }
      else
      {
        GPIOB->BSRR = GPIO_BSRR_BR10;      // When not ready to accept more data (e.g. while transmitting data process) 
      }
      
    
}

void portsEnable(void)                        /* Enable PortA and PortB */
{
  // Enable clock for Ports (A & B) on "APB2" Bus.
  RCC->APB2ENR |= RCC_APB2ENR_IOPAEN;       // Enable PortA Clock
  RCC->APB2ENR |= RCC_APB2ENR_IOPBEN;       // Enable PortB Clock
}

void pinsConfig(void)                         //Configure the used pins.
{  
  //Set pin "PB1" as output push-pull (Red LED)
  GPIOB->CRL |= ((1<<4) | (1<<5));          //Set Pin to Output 50Mhz max speed
  GPIOB->CRL &= ~((1<<6) | (1<<7));         //Configure Pin as Push-Pull


  //Set Pin "PB9" as Input Pulled-Up (Push Button Pin)
  GPIOB->CRH &= ~(1<<6);                   //Set PB9 to input "pullup|pulldown"
  GPIOB->CRH |= (1<<7);
  GPIOB->ODR |= (1<<9);                    //Set PB9 input pin as Pull-up pin.


  //Set pin "PB10" as output push-pull (Blue LED)
  GPIOB->CRH |= ((1<<9) | (1<<8));          //Set Pin to Output 50Mhz max speed
  GPIOB->CRH &= ~((1<<11) | (1<<10));       //Configure Pin as Push-Pull

  //Set pin "PB11" as output push-pull (Green LED)
  GPIOB->CRH |= ((1<<12) | (1<<13));        //Set Pin to Output 50Mhz max speed
  GPIOB->CRH &= ~((1<<14) | (1<<15));       //Configure Pin as Push-Pull


  //Set pin PA0 as Analog input
  GPIOA->CRL &= ~((1<<0) | (1<<1));          // Make sure the Mode registers are 00 for input
  GPIOA->CRL &= ~((1<<2) | (1<<3));          // Set the CNF registers to 00 for input analog
  
} // End PinsConfig()

void delay(uint32_t delay)                    /* Psudo-delay in Milliseconds */
{
    for(uint32_t i = 0; i <= delay; i++)
    {
      // Looping to delay!
    }
}

Answer 1

也許下面的鏈接對你有幫助： stm32 dead lock