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[PIC] Two PIC 18f4620 1 as master.2nd is slave I2C problem

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ubuntuman

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Two PIC 18f4620 , 1 as master.2nd is slave I2C problem

The complete Master code . HS oscillator mode .4MHZ
Code:
const long int crystalOscillator =4000000;
unsigned short int temp=0;
//#####################################################################################
void I2C_Master_Init(const unsigned long int c)
{
 SSPCON1 = 0b00101000;
 SSPCON2 = 0;
 SSPADD = (crystalOscillator/(4*c))-1;
 SSPSTAT = 0b11000000;
 TRISC.B3 = 1; //Setting as input as given in datasheet
 TRISC.B4 = 1; //Setting as input as given in datasheet
}

void I2C_Master_Wait()
{
 while ((SSPSTAT & 0x04) || (SSPCON2 & 0x1F));
}

void I2C_Master_Start()
{
 I2C_Master_Wait();
 SSPCON2.SEN = 1;
}

void I2C_Master_RepeatedStart()
{
 I2C_Master_Wait();
 SSPCON2.RSEN = 1;
}

void I2C_Master_Stop()
{
 I2C_Master_Wait();
 SSPCON2.PEN = 1;
}

void I2C_Master_Write(unsigned short int d)
{
 I2C_Master_Wait();
 SSPBUF = d;
}

unsigned short int I2C_Master_Read(unsigned short int a)
{
 unsigned short int temp;
 I2C_Master_Wait();
 SSPCON2.RCEN = 1;
 I2C_Master_Wait();
 temp = SSPBUF;
 I2C_Master_Wait();
 if(a==1){SSPCON2.ACKDT=1;}
 else{SSPCON2.ACKDT=0;}
 SSPCON2.ACKEN = 1;
 return temp;
}

void main()
{
 I2C_Master_Init(100000); //Initialize I2C Master with 100KHz clock
 //I2C1_Init(50000);
 OSCTUNE.PLLEN=0;
 Delay_ms(500);
 TRISB=0;
 PORTB=0;
 while(1)
 {

 I2C_Master_Start();
 I2C_Master_Write(0xAA); //Write data
 //I2C_Master_Write(0x00);
 I2C_Master_Stop();
 
 Delay_ms(5000);
 }
}

The complete Slave code . HS oscillator mode .4MHZ
Code:
//##############################################################################
unsigned short int  zed=0;
volatile unsigned short int  new =0 ,dataRead=0 , dataWrite=0;
unsigned char dataReadCh[7] , dataWriteCh[7];
//##############################################################################
void interrupt()
{
 if(PIR1.SSPIF == 1)
 {
  SSPCON1.CKP = 0;
  new=1;
  zed = SSPBUF;
  PIR1.SSPIF = 0;
  SSPCON1.CKP = 1;
  if ((SSPCON1.SSPOV) || (SSPCON1.WCOL))
  {
   zed = SSPBUF; // Read the previous value to clear the buffer
   SSPCON1.SSPOV = 0; // Clear the overflow flag
   SSPCON1.WCOL = 0; // Clear the collision bit
   SSPCON1.CKP = 1;
  }
  if(!SSPSTAT.D_A && !SSPSTAT.R_W)
  {
   while(!SSPSTAT.BF){};
   while(SSPSTAT.BF){dataRead = SSPBUF;}
   SSPCON1.CKP = 1;
  }
  else if(SSPSTAT.D_A && SSPSTAT.R_W)
  {
   while(SSPSTAT.BF){zed = SSPBUF;}
   SSPBUF = dataWrite ;
   SSPCON1.CKP = 1;
   while(SSPSTAT.BF){};
  }
  PIR1.SSPIF = 0;
 }
}
//##############################################################################
void I2C_Slave_Init(unsigned short int address)
{
 SSPSTAT = 0b11000000;
 SSPADD = address;
 SSPCON1 = 0b00110110;
 SSPCON2 = 0b00000001;
 //TRISC.B3 = 1; //Setting as input as given in datasheet
 //TRISC.B4 = 1; //Setting as input as given in datasheet
 TRISC=0b00011000;
 LATC= 0b00011000;
 INTCON = 0b00000000;
 INTCON.PEIE = 1;
 INTCON.GIE = 1;
 PIE1.SSPIE = 1;
 PIR1.SSPIF = 0;
 while(SSPSTAT.BF){zed = SSPBUF;SSPCON1.SSPOV = 0;SSPCON1.WCOL = 0;}
}
//##############################################################################

void main() 
{
  OSCTUNE.PLLEN=0;
  ADCON1=0b00001111;
  TRISA.B0 = 0; //PORTD as output
  PORTA.B0=0;
  I2C_Slave_Init(0xAA); //Initialize as a I2C Slave with address 0x30
  while(1)
  {
   if(new==1)
     {
      PORTA.B0=1;
      new=0;
     }
   }
}

The problem is each time I send 0xAA from the master to the slave after putting 0xAA to slave SSPADD, I get NOTACK signal. I don't know where is the thing who doesn't work.


Here you are, screenShot for the WaveForm i get 2VGF4Gk.png
 
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barry

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Re: Two PIC 18f4620 , 1 as master.2nd is slave I2C problem

just looking at this briefly, I'm confused by the statement:

SSPADD = (crystalOscillator/(4*c))-1;

That sure doesn't match the address declared in the slave module which is 0xaa,(but commented as 0x30.)
 

ubuntuman

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Re: Two PIC 18f4620 , 1 as master.2nd is slave I2C problem

just looking at this briefly, I'm confused by the statement:

SSPADD = (crystalOscillator/(4*c))-1;

That sure doesn't match the address declared in the slave module which is 0xaa,(but commented as 0x30.)

In master mode SSPADD of the master pic is filled not with address of the slave . It is filled with a value that is used in Baud rate counter to generate the clock pulses of the system over SCL pin
 

barry

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Re: Two PIC 18f4620 , 1 as master.2nd is slave I2C problem

Ah, my mistake. Have you looked at signals with an oscilloscope? That might help a lot. Or use the debugger.
 

ubuntuman

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Re: Two PIC 18f4620 , 1 as master.2nd is slave I2C problem

Ah, my mistake. Have you looked at signals with an oscilloscope? That might help a lot. Or use the debugger.

Could u please check the attaches in the main thread post above
 
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barry

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Re: Two PIC 18f4620 , 1 as master.2nd is slave I2C problem

Could u please check the attaches in the main thread post above

AHA! Your problem is that 0xAA is an invalid address. I2C addresses are 7 bit, you've got an 8-bit address.
 

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