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标题: EFM8BB1测评---模拟I2C读取AT24C04 [打印本页]

作者: Cjy_JDxy 时间: 2019-12-2 19:38
标题: EFM8BB1测评---模拟I2C读取AT24C04
今晚捣鼓了一下模拟I2C读取AT24C04。
代码：
//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------
#include "SI_EFM8BB1_Register_Enums.h"             // SFR declarations
#include "InitDevice.h"

#define uchar unsigned char
#define uint unsigned int
//-----------------------------------------------------------------------------
// Pin Declarations
//-----------------------------------------------------------------------------

SI_SBIT(LED, SFR_P1, 4); // LED
SI_SBIT(S1, SFR_P0, 2);    // BTN0
SI_SBIT(SCL, SFR_P1, 6); // SCL
SI_SBIT(SDA, SFR_P0, 7);    // SDA
//-----------------------------------------------------------------------------
// Global Constants
//-----------------------------------------------------------------------------

#define SYSCLK    24500000/8       // Clock speed in Hz (default)

#define SW_PRESSED          0
#define SW_NOT_PRESSED    1

#define LED_ON             0
#define LED_OFF             1
//#define SCL_1             1
//#define SCL_0 0
//#define SDA_1 1
//#define SDA_0 0

unsigned char buffer[3];

void InitSCL(void)
{
P1MDOUT = P1MDOUT_B6__OPEN_DRAIN ;

}

void InitSDAInput(void)
{
//P1MDIN = P1MDIN_B6__BMASK | P1MDIN_B6__SHIFT | P1MDIN_B6__DIGITAL;
//P1MDIN = P1MDIN_B7__DIGITAL ;
//P1SKIP = P1SKIP_B7__SKIPPED ;
P0SKIP =  P0SKIP_B7__SKIPPED;
}

void InitSDAOutput(void)
{
P0MDOUT = P0MDOUT_B7__OPEN_DRAIN ;

}

void Delay(unsigned char us)  //5,7,9
{
  while(--us);
}

//-----------------------------------------------------------------------------------------
//????:Delayms()
//-----------------------------------------------------------------------------------------
void Delayms(unsigned int ims)
{
  unsigned int i,j;
for(i=0;i<ims;i++)
   for(j=0;j<65;j++) { Delay(1); }
}

void Start()

{
InitSDAOutput();
InitSCL();
SCL=1;
Delay(10);
SDA=1;
Delay(10);
SDA=0;
Delay(10);
SCL=0;
Delay(10);
}

void Stop()

{
InitSDAOutput();
InitSCL();
SDA=0;
Delay(10);
SCL=1;
Delay(10);
SDA=1;
Delay(10);
}

char ACK ()

{

char c;
InitSDAOutput();
InitSCL();
SDA=1;
Delay(10);
SCL=1;
Delay(10);
InitSDAInput();
Delay(10);
if(SDA)
c=1;
else
c=0;
Delay(10);
InitSDAOutput();
Delay(10);
SCL=0;
Delay(10);
return c;

}

void SendChar(unsigned char ch)

{

  unsigned char i;

  i=8;
InitSDAOutput();
InitSCL();
  do

  {
if(ch&0x80)
   SDA=1;
else
   SDA=0;
Delay(10);
SCL=1;
Delay(10);
SCL=0;
Delay(10);
ch<<=1;

  }while(--i!=0);

}
unsigned char RecChar()

{

  unsigned char i,j;

  i=8;
  j=0;
InitSCL();
InitSDAInput();
Delay(10);
  do

  {

SCL=1;
Delay(10);
j=(j<<1);
if(SDA)
   j=j|SDA;
Delay(10);
SCL=0;
Delay(10);
  }while(--i!=0);
InitSDAOutput();
  return j;

}

void WriteChar(unsigned int addr,unsigned char ch)

{

  unsigned char c;

  c=((*((unsigned char *)&addr))<<1)&0x02;

  Start();

  SendChar(0xa0|c);

  ACK();

  SendChar(addr);

  ACK();

  SendChar(ch);

  ACK();
  Stop();

  for(ch=0xff;ch!=0;ch--) ;

}

unsigned char ReadChar(unsigned int addr)

{

  unsigned char ch;

  ch=((*((unsigned char *)&addr))<<1)&0x02;

  Start();

  SendChar(0xa0|ch);

  ACK();

  SendChar(addr);

  ACK();

  Start();

  SendChar(0xa1|ch);

  ACK();

  ch=RecChar();

  Stop();

  return ch;

}

//-----------------------------------------------------------------------------
// SiLabs_Startup() Routine
// ----------------------------------------------------------------------------
// This function is called immediately after reset, before the initialization
// code is run in SILABS_STARTUP.A51 (which runs before main() ). This is a
// useful place to disable the watchdog timer, which is enable by default
// and may trigger before main() in some instances.
//-----------------------------------------------------------------------------
void SiLabs_Startup (void)
{
  // Disable the watchdog here
}

//-----------------------------------------------------------------------------
// main() Routine
// ----------------------------------------------------------------------------
// Note: the software watchdog timer is not disabled by default in this
// example, so a long-running program will reset periodically unless
// the timer is disabled or your program periodically writes to it.
//
// Review the "Watchdog Timer" section under the part family's datasheet
// for details. To find the datasheet, select your part in the
// Simplicity Launcher and click on "Data Sheet".
//-----------------------------------------------------------------------------
int main (void)
{
unsigned int i;
char flag=0;

enter_DefaultMode_from_RESET();
InitSCL();
InitSDAOutput();
buffer[0]=ReadChar(0);
Delay(100);          //??????
WriteChar(0,0x55);
Delayms(20);
WriteChar(1,0xaa);
Delayms(20);
WriteChar(2,0x25);
Delayms(20);
buffer[0]=ReadChar(1);
buffer[1]=ReadChar(2);
buffer[2]=ReadChar(0);
  while (1)
  {

  }                            // Spin forever
}

效果图：
[attach]1350432[/attach]

[attach]1350434[/attach]

作者: Yiqil 时间: 2022-3-18 09:40
InitSCL()和InitSDAOutput() 置为OPEN_DRAIN是为了拉高SCL和SDA吗？

作者: suguibin02 时间: 2022-12-1 13:06
楼主，愿意接个项目吗？也是EFM8单片机，联系VX: "GPS_CXWL"

作者: Cjy_JDxy 时间: 2023-1-12 23:50
接不了，没时间。

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