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Gon Guest
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Problems with I2C!!! HELP |
Posted: Wed Dec 19, 2007 3:24 am |
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Hi! I have some problems with the bus I2C! I've a PIC16F876A for the master and a PIC18F4520 for the SLAVE. Please, anyone can help me and tell me what on my code y wrong?
I tried everything but it's imposible! help please
This is my code:
***************MASTER*****************************
Code:
#include <16F876A>
#device adc=8
#use delay(clock=4000000)
#FUSES NOWDT //No Watch Dog Timer
#FUSES HS //Crystal osc <= 4mhz
#FUSES NOPUT //No Power Up Timer
#FUSES NOPROTECT //Code not protected from reading
#FUSES NODEBUG //No Debug mode for ICD
#FUSES NOBROWNOUT //No brownout reset
#FUSES NOLVP //No low voltage prgming, B3(PIC16) or B5(PIC18) used for I/O
#FUSES NOCPD //No EE protection
#FUSES NOWRT //Program memory not write protected
#use i2c(Master,sda=PIN_C4,scl=PIN_C3)
#include "C:\Documents and Settings\bizintek01\Mis documentos\I2C\Master\master.h"
#byte port_a=5
#byte port_b=6
#byte port_c=7
#byte port_d=8
#byte port_e=9
//#org 0x1F00, 0x1FFF void loader16F876A(void) {}
static int a,b,c=25,d=15,e,f;
void main()
{
set_tris_a(0x00);
set_tris_b(0x00);
set_tris_c(0x00);
while(1)
{
i2c_start();
i2c_write(0xc0); //direccion de slave
a=i2c_read(0x00); //leo buffer
b=i2c_read(0x01);
i2c_stop();
}
}
***************SLAVE*********************************
Code:
#include <18F4520>
#device adc=8
#FUSES NOWDT //No Watch Dog Timer
#FUSES WDT128 //Watch Dog Timer uses 1:128 Postscale
#FUSES HS //Crystal osc <= 4mhz
#FUSES NOPROTECT //Code not protected from reading
#FUSES BROWNOUT //Reset when brownout detected
#FUSES BORV25 //Brownout reset at 2.5V
#FUSES NOPUT //No Power Up Timer
#FUSES NOCPD //No EE protection
#FUSES STVREN //Stack full/underflow will cause reset
#FUSES DEBUG //No Debug mode for ICD
#FUSES NOLVP //Low Voltage Programming on B3(PIC16) or B5(PIC18)
#FUSES NOWRT //Program memory not write protected
#FUSES NOWRTD //Data EEPROM not write protected
#FUSES IESO //Internal External Switch Over mode enabled
#FUSES FCMEN //Fail-safe clock monitor enabled
#FUSES PBADEN //PORTB pins are configured as analog input channels on RESET
#FUSES NOWRTC //configuration not registers write protected
#FUSES NOWRTB //Boot block not write protected
#FUSES NOEBTR //Memory not protected from table reads
#FUSES NOEBTRB //Boot block not protected from table reads
#FUSES NOCPB //No Boot Block code protection
#FUSES LPT1OSC //Timer1 configured for low-power operation
#FUSES MCLR //Master Clear pin enabled
#FUSES NOXINST //Extended set extension and Indexed Addressing mode disabled (Legacy mode)
#use delay(clock=20000000)
#use i2c(Slave,sda=PIN_C4,scl=PIN_C3,address=0xc0)
BYTE address, buffer[0x10];
#INT_SSP
void ssp_interupt ()
{
BYTE incoming, state;
state = i2c_isr_state();
if(state < 0x80) //Master is sending data
{
incoming = i2c_read();
if(state == 1) //First received byte is address
address = incoming;
if(state == 2) //Second received byte is data
buffer[address] = incoming;
}
if(state == 0x80) //Master is requesting data
{
i2c_write(buffer[address]);
}
}
int i;
void main()
{
setup_adc_ports(NO_ANALOGS|VSS_VDD);
setup_adc(ADC_OFF|ADC_TAD_MUL_0);
setup_psp(PSP_DISABLED);
setup_wdt(WDT_OFF);
setup_timer_0(RTCC_INTERNAL);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_timer_3(T3_DISABLED|T3_DIV_BY_1);
setup_comparator(NC_NC_NC_NC);
setup_vref(FALSE);
setup_oscillator(False);
// TODO: USER CODE!!
set_tris_a(0);
set_tris_b(0);
address = 0x00;
for (i=0;i<0x10;i++)
buffer[i] = 0x00;
enable_interrupts(INT_SSP);
enable_interrupts(GLOBAL);
while (TRUE)
{
buffer[0x00]=0;
buffer[0x01]=1; //doy valores al buffer para luego poder leerlos
}
}
Thank you |
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rnielsen
Joined: 23 Sep 2003 Posts: 852 Location: Utah
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Posted: Wed Dec 19, 2007 9:46 am |
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Quote: | ***************MASTER*****************************
#FUSES NOPUT //No Power Up Timer Change to PUT - good thing to have
set_tris_a(0x00); <--- these are not needed and require fast_io
set_tris_b(0x00); <---
set_tris_c(0x00); <---
i2c_start(); // try placing delays between each command at first
delay_us(50);
i2c_write(0xc0); //direccion de slave
delay_us(50);
a=i2c_read(0x00); //leo buffer <--- this statement tells the slave that play time is over, the zero tells it the Master is finished
delay_us(50);
b=i2c_read(0x01); <---this one should have 0x00 in it
delay_us(50);
i2c_stop();
// place a delay here, in your while() loop, of around 500ms to 1 second. You're looping rather fast. Give the slave some time to breath while you figure things out.
***************SLAVE*********************************
#FUSES NOPUT //No Power Up Timer <--- use PUT here too
#FUSES PBADEN // <--- use NOPBADEN if you're not using the ADC
set_tris_a(0); <--- not needed
set_tris_b(0); <---
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I wasn't very thorough but these are what stood out for now.
Ronald
Last edited by rnielsen on Wed Dec 19, 2007 11:51 am; edited 1 time in total |
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PCM programmer
Joined: 06 Sep 2003 Posts: 21708
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