藍橋杯嵌入式—基礎模塊：ADC+AT24C02

一、模塊
ADC+AT24C02

二、實現功能
1.在LCD上顯示電壓
2.將電壓的100倍存入AT24C02，並讀出，並顯示在LCD上。

三、代碼
1.初始化
tx.h

#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;
}

tx.h

/*
  程序說明: CT117E嵌入式競賽板LCD驅動程序
  軟件環境: Keil uVision 4.10 
  硬件環境: CT117E嵌入式競賽板
  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);



#endif /* __TX_H */

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

2.I2C
i2c.c

void i2c_write(u16 add,u8 data){
  I2CStart();
  I2CSendByte(0xa0);
  I2CWaitAck();
  I2CSendByte(add);
  I2CWaitAck();
  I2CSendByte(data);
  I2CWaitAck();
  I2CStop();
}

u8 i2c_read(u16 add){
  u8 temp;
  I2CStart();
  I2CSendByte(0xa0);
  I2CWaitAck();
  I2CSendByte(add);
  I2CWaitAck();

  I2CStart();
  I2CSendByte(0xa1);
  I2CWaitAck();
  temp=I2CReceiveByte();
  I2CSendAck();
  I2CStop();
  return temp;
}

3.主函數
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;

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);
	
	
	i2c_init();
	Adc1_Init();
	
	while(1){
	   adc_value=Get_adc()*3.3/4096;
	   sprintf((char*)str,"  ADC : %.2fV      ",adc_value);
	   LCD_DisplayStringLine(Line2,str);

	  
	   i2c_write(0x00,adc_value*100); Delay_Ms(5);
	   temp=i2c_read(0x00);Delay_Ms(5);

	   sprintf((char*)str,"  Temp : %dV     ",temp);
	   LCD_DisplayStringLine(Line4,str);

	}
}

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

四、總結
有一點值得注意，存入AT24C02在讀出的數據在255以上就不對應了。原因在於I2C讀取時的數據爲8位，最大爲255，而超過255的數值，就重新從0開始了，即在這裏，255+1=0。