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I2C Problem in pic24FJ128GA010

 
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Prada



Joined: 22 Dec 2011
Posts: 3

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I2C Problem in pic24FJ128GA010
PostPosted: Thu Dec 22, 2011 5:54 am     Reply with quote

Hi

I am currently developing a semaphore system, based on pic24fj128ga010, everything is fine except the I2C communications:
The sda & scl pins are always high...

The code is attached, if anyone know the cause I was grateful:)
Code:

#include <24FJ128GA010.h>

#FUSES NOWDT //No Watch Dog Timer
#FUSES NOJTAG //JTAG disabled
#FUSES NOPROTECT //Code not protected from reading
#FUSES NOWRT //Program memory not write protected
#FUSES NODEBUG //No Debug mode for ICD
//#FUSES ICSP1 //ICD uses PGC1/PGD1 pins
#FUSES WINDIS //Watch Dog Timer in non-Window mode
#FUSES NOIESO //Internal External Switch Over mode disabled
#FUSES PR //Primary Oscillator
#FUSES NOCKSFSM //Clock Switching is disabled, fail Safe clock monitor is disabled
#FUSES NOOSCIO //OSC2 is clock output
#FUSES HS //External clock with CLKOUT

//#use fast_io(A)
#use fast_io(E)
#use fast_io(C)

#use delay(clock=32000000)
#use i2c(Master,sda=PIN_A3,scl=PIN_A2)
#include <max7312.c>

(......)

max7312.c
Code:

#ifndef MAX7312_DATA
#define MAX7312_DATA  PIN_A3
#define MAX7312_CLK   PIN_A2
#endif

#use i2c(Master,sda=PIN_A3,scl=PIN_A2)

//prototypes
int8 max7312_read(int8 device, int8 address);  //reads 7312 control register
void max7312_write(int8 device, int8 address, int8 data);   //writes 7312 control register

(......)

Thank you for listening and if you know the solution ;)
temtronic



Joined: 01 Jul 2010
Posts: 9226
Location: Greensville,Ontario

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PostPosted: Thu Dec 22, 2011 7:01 am     Reply with quote

Do you have the correct pullup resistors on the I2C lines for your speed,PCB layout,etc.?

Have you tried another I2C device(say an RTC like the DS1307 )?

Only code snippets are shown, we'll need to see a small,compileable program that fails to offer more help.
Prada



Joined: 22 Dec 2011
Posts: 3

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I2C problem pic24fj128ga010
PostPosted: Thu Dec 22, 2011 7:57 am     Reply with quote

Thanks for the reply,
I have use 4.7k pullup resistors.
I've done the scan with the oscilloscope, and there is no clock or data.
following is a small program to compile.

Code:

//Main.c

#include <24FJ128GA010.h>

#FUSES NOWDT //No Watch Dog Timer
#FUSES NOJTAG //JTAG disabled
#FUSES NOPROTECT //Code not protected from reading
#FUSES NOWRT //Program memory not write protected
#FUSES NODEBUG //No Debug mode for ICD
//#FUSES ICSP1 //ICD uses PGC1/PGD1 pins
#FUSES WINDIS //Watch Dog Timer in non-Window mode
#FUSES NOIESO //Internal External Switch Over mode disabled
#FUSES PR //Primary Oscillator
#FUSES NOCKSFSM //Clock Switching is disabled, fail Safe clock monitor is disabled
#FUSES NOOSCIO //OSC2 is clock output
#FUSES HS //External clock with CLKOUT
//#use fast_io(A)
#use fast_io(E)
#use fast_io(C)
#use delay(clock=32000000)
//#use i2c(MASTER, sda=PIN_G3, scl=PIN_G2, Fast, Force_sw)
#word AD1PCFG=0xffff
#use i2c(Master,sda=PIN_A3,scl=PIN_A2)
#include <max7312.c>

int1 RADAR1,RADAR2,PEAO;


void main(void) {

delay_ms(1000);
   
while(1){
   output_high(PIN_A4);
   delay_ms(1000);
}

   delay_ms(1000);
   delay_ms(1000);

   max7312_init_output(0x46) ;
   delay_ms(500);
   delay_ms(1000);
   delay_ms(1000);

   delay_ms(1000);

   PEAO=0;
   RADAR1=0;
   RADAR2=0;
   
    while(true)
    {
     max7312_write(0x46,0x02,0b01001100); //1ª fase
     max7312_write(0x44,0x02,0b00000010);
     
     max7312_write(0x46,0x02,0b01001010);//2ª fase
     max7312_write(0x44,0x02,0b00000010);
     
     max7312_write(0x46,0x02,0b10100001); //3ª fase
     max7312_write(0x44,0x02,0b00000001);
     
     max7312_write(0x46,0x02,0b10010001); //4ª fase
     max7312_write(0x44,0x02,0b00000001);
    }

}


Code:

//max7312.c

#ifndef MAX7312_DATA
#define MAX7312_DATA  PIN_A3
#define MAX7312_CLK   PIN_A2
#endif

#use i2c(Master,sda=PIN_A3,scl=PIN_A2)

//prototypes

int8 max7312_read(int8 device, int8 address);  //reads 7312 control register
void max7312_write(int8 device, int8 address, int8 data);   //writes 7312 control register

void max7312_init_output(int8 device) { //Alterei esta função
   output_float(MAX7312_CLK);
   output_float(MAX7312_DATA);

   max7312_write(device,0x06,0x00);  //configura porto 1 como saída

   max7312_write(device,0x02,0x00); //Coloca o porto 1 como saída(Mudar para 0x00 onde está o 0xFF)
}

void max7312_init_input(int8 device) { //Alterei esta função
   output_float(MAX7312_CLK);
   output_float(MAX7312_DATA);

   max7312_write(device,0x06,0x11);  //configura porto 1 como entrada
}


int8 max7312_read(int8 device, int8 commandByte) {
   BYTE data;

   i2c_start();
   i2c_write(device);       //endereço do escravo
   i2c_write(commandByte);  //commando de entrada
   i2c_start();
   i2c_write(commandByte | 1);//escreve endereço com read=1
   data=i2c_read(0);         //sem ack pq vai parar a seguir
   i2c_stop();
   return(data);
}

void max7312_write(int8 device, int8 address, int8 data) {
   i2c_start();
   i2c_write(device);
   i2c_write(address);
   i2c_write(data);
   i2c_stop();
}
FvM



Joined: 27 Aug 2008
Posts: 2337
Location: Germany

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PostPosted: Thu Dec 22, 2011 5:09 pm     Reply with quote

The shown code executes 2 lines continuously, but no I2C actions.

Code:
while(1){
   output_high(PIN_A4);
   delay_ms(1000);
}
Prada



Joined: 22 Dec 2011
Posts: 3

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I2C problem pic24fj128ga010
PostPosted: Fri Dec 23, 2011 3:53 am     Reply with quote

It works Very Happy

I was so focused on the I2C set, which I did not notice this error in the program Shocked
Thanks for the help Razz
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