蓝桥杯嵌入式—基础模块：USART2+RTC

一、模块
USART2+RTC

二、实现功能
在AccessPort软件中输入C，返回电压；
输入T，返回RTC时间。

三、代码
1.初始化函数
tx.c

#include "tx.h"

void Adc1_Init(void){
  ADC_InitTypeDef ADC_InitStructure;
  GPIO_InitTypeDef GPIO_InitStructure;

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1 | RCC_APB2Periph_GPIOB, ENABLE);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
  ADC_InitStructure.ADC_ScanConvMode = DISABLE;
  ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
  ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
  ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
  ADC_InitStructure.ADC_NbrOfChannel = 1;
  ADC_Init(ADC1, &ADC_InitStructure);
  ADC_DMACmd(ADC1, ENABLE);
  
  /* Enable ADC1 */
  ADC_Cmd(ADC1, ENABLE);

  /* Enable ADC1 reset calibration register */   
  ADC_ResetCalibration(ADC1);
  /* Check the end of ADC1 reset calibration register */
  while(ADC_GetResetCalibrationStatus(ADC1));

  /* Start ADC1 calibration */
  ADC_StartCalibration(ADC1);
  /* Check the end of ADC1 calibration */
  while(ADC_GetCalibrationStatus(ADC1));

}

u16 Get_adc(void){
  u16 temp;
  ADC_RegularChannelConfig(ADC1, ADC_Channel_8, 1, ADC_SampleTime_239Cycles5);
  ADC_SoftwareStartConvCmd(ADC1, ENABLE);
  while(ADC_GetFlagStatus(ADC1,ADC_FLAG_EOC)==0);
  temp=ADC_GetConversionValue(ADC1);
  ADC_SoftwareStartConvCmd(ADC1, DISABLE);
  return temp;
}

void Usart2_Init(void){
  USART_InitTypeDef USART_InitStructure;
  GPIO_InitTypeDef GPIO_InitStructure;
  NVIC_InitTypeDef NVIC_InitStructure;

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); 
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE); 

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);

  USART_InitStructure.USART_BaudRate = 9600;
  USART_InitStructure.USART_WordLength = USART_WordLength_8b;
  USART_InitStructure.USART_StopBits = USART_StopBits_1;
  USART_InitStructure.USART_Parity = USART_Parity_No;
  USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
  USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
  
  /* Configure USARTy */
  USART_Init(USART2, &USART_InitStructure);
  USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);
  USART_Cmd(USART2, ENABLE);
}

void Send_string(u8 *str){
   u8 i=0;
   while(str[i]!=0){
   	 USART_SendData(USART2,str[i]);
	 while(USART_GetFlagStatus(USART2,USART_FLAG_TXE)==0);
	 i++;
   }	 
}

void RTC_Init(u8 HH,u8 MM,u8 SS){
  NVIC_InitTypeDef NVIC_InitStructure;
  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);

  /* Enable the RTC Interrupt */
  NVIC_InitStructure.NVIC_IRQChannel = RTC_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR | RCC_APB1Periph_BKP, ENABLE);

  /* Allow access to BKP Domain */
  PWR_BackupAccessCmd(ENABLE);

  /* Reset Backup Domain */
  BKP_DeInit();

  /* Enable the LSI OSC */
  RCC_LSICmd(ENABLE);
  /* Wait till LSI is ready */
  while (RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET)
  {}
  /* Select the RTC Clock Source */
  RCC_RTCCLKConfig(RCC_RTCCLKSource_LSI);

  /* Enable RTC Clock */
  RCC_RTCCLKCmd(ENABLE);

  /* Wait for RTC registers synchronization */
  RTC_WaitForSynchro();

  /* Wait until last write operation on RTC registers has finished */
  RTC_WaitForLastTask();

  /* Enable the RTC Second */
  RTC_ITConfig(RTC_IT_SEC, ENABLE);

  /* Wait until last write operation on RTC registers has finished */
  RTC_WaitForLastTask();

  /* Set RTC prescaler: set RTC period to 1sec */
  RTC_SetPrescaler(40000-1);

  /* Wait until last write operation on RTC registers has finished */
  RTC_WaitForLastTask();

  RTC_SetCounter(3600*HH+60*MM+SS);
  RTC_WaitForLastTask();

}

tx.h

/*
  程序说明: CT117E嵌入式竞赛板LCD驱动程序
  软件环境: Keil uVision 4.10 
  硬件环境: CT117E嵌入式竞赛板
  日    期: 2011-8-9
*/
/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __TX_H
#define __TX_H

/* Includes ------------------------------------------------------------------*/
#include "stm32f10x.h"

void Adc1_Init(void);
u16 Get_adc(void);
void Usart2_Init(void);
void Send_string(u8 *str);
void RTC_Init(u8 HH,u8 MM,u8 SS);



#endif /* __TX_H */

/******************* (C) COPYRIGHT 2008 STMicroelectronics *****END OF FILE****/

2.中断函数
stm32f10x_it.c中

extern u8 RXD_flag;
extern u8 RXD_buf[20];
u16 RXD_count=0;
void USART2_IRQHandler(void)
{
  u16 temp;
  if(USART_GetITStatus(USART2, USART_IT_RXNE) != RESET)
  {
    USART_ClearITPendingBit(USART2, USART_IT_RXNE);
    temp = USART_ReceiveData(USART2);
    if(temp=='\n'){
      RXD_flag=1;
	  RXD_count=0;
      USART_ITConfig(USART2, USART_IT_RXNE, DISABLE);
    }
	else
	  RXD_buf[RXD_count++]=temp; 
  }
}

extern u16 time;
extern u8 hour,min,sec;

void RTC_IRQHandler(void)
{
  if (RTC_GetITStatus(RTC_IT_SEC) != RESET)
  {	    
    RTC_ClearITPendingBit(RTC_FLAG_SEC);  
	time=RTC_GetCounter();
	if(time==23*3600+59*60+59)
	  RTC_SetCounter(0);
	hour=time/3600;
	min=time%3600/60;
	sec=time%3600%60;
  }
}

3.主函数
main.c

#include "stm32f10x.h"
#include "lcd.h"
#include "tx.h"
#include "stdio.h"
#include "i2c.h"

u32 TimingDelay = 0;

u8 str[20];
float adc_value;
u8 temp;
u8 i;

u8 RXD_flag=0;
u8 RXD_buf[20];

u16 time;
u8 hour,min,sec;
void Usart2_action(void);
void Delay_Ms(u32 nTime);

//Main Body
int main(void)
{
	SysTick_Config(SystemCoreClock/1000);

	Delay_Ms(200);
	
	STM3210B_LCD_Init();
	LCD_Clear(Blue);
	LCD_SetBackColor(Blue);
	LCD_SetTextColor(White);
	
	Adc1_Init();
	Usart2_Init();
	RTC_Init(12,50,50);

	while(1){
	   KEY_Driver();
	   adc_value=Get_adc()*3.3/4096;
	   sprintf((char*)str,"  ADC : %.2fV      ",adc_value);
	   LCD_DisplayStringLine(Line2,str);

	   sprintf((char*)str,"  Time:%d-%d-%d",hour,min,sec);
	   LCD_DisplayStringLine(Line6,str);

	   if(RXD_flag){
	   	  RXD_flag=0;
		  Usart2_action();
	   }

	}
}

void Usart2_action(void){
  if(RXD_buf[0]=='C'){
  	sprintf((char*)str,"ADC : %.2fV\r\n",adc_value);
	Send_string(str);
  
  }
  else if(RXD_buf[0]=='T'){
    sprintf((char*)str,"Time:%.2d-%.2d-%.2d\r\n",hour,min,sec);
	Send_string(str);
  }
  for(i=0;i<20;i++)
    RXD_buf[i]=0;
  USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);
}

void Delay_Ms(u32 nTime)
{
	TimingDelay = nTime;
	while(TimingDelay != 0);	
}