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Nopnop
Joined: 10 Aug 2007
Posts: 7
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| I2C FORCE_HW problems |
 Posted: Fri Aug 10, 2007 3:30 pm |
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Hi, I am French, sorry for my English.
If I have understood the I2C parameter FORCE_HW manage the I2C bus automatically.
When I execute this code I must add a delay_ms(5) after I2C_stop() for my data is written in EEPROM 24FC1025.
Can you tell me if the delay_ms(5) after I2C_stop is obligatory.
Thanks for your answers.
vAdresse=0x0000;
While(true)
{
i2c_start();
i2c_write(0xa0); // Contrôle
i2c_write(vAdresse>>8); // Adresse
i2c_write(vAdresse); // Adresse
i2c_write(vData>>8); // Data poids faible
i2c_write(vData); // Data poids fort
i2c_stop();
} |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Aug 10, 2007 3:36 pm |
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Download the eeprom data sheet.
http://ww1.microchip.com/downloads/en/DeviceDoc/21941B.pdf
Look at the Write Cycle Time (Param No. 17 on page 3). It's 5 ms.
The CCS driver uses "Ack Polling". This may allow the wait for
the write operation to be shorter than 5 ms. Why not use the
CCS driver ? Here's the file location:
| Quote: | | c:\Program Files\PICC\Drivers\241025.c |
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Nopnop
Joined: 10 Aug 2007
Posts: 7
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| Posted: Tue Sep 04, 2007 2:47 pm |
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Hi, PCM Programmer thanks for the solution of EEPROM.
Now I have a problem between two PIC 18F452.
When I send the address and data I don’t have the good result.
I have 00 00
And 01 90
And 90 90
Normally I should have
00 00
90 01
90 02
90 03
.. ..
If anyone have an ideas
Master code
| Code: |
#include <18F452.h>
#fuses NOWDT,WDT128,HS, NOPROTECT, NOOSCSEN, BROWNOUT, BORV20, NOPUT, STVREN, NODEBUG, NOLVP, NOWRT, NOWRTD, NOWRTB, NOWRTC, NOCPD, NOCPB, NOEBTR, NOEBTRB
#use delay(clock=20000000)
#use i2c(MASTER, SCL=PIN_C3, SDA=PIN_C4, FAST=400000, FORCE_HW)
int data;
void main()
{
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_wdt(WDT_OFF);
enable_interrupts(GLOBAL);
set_tris_A(0b00010000); // Paramétrage du port A
set_tris_B(0b00110000); // Paramétrage du port B
set_tris_C(0b10011001); // Paramétrage du port C
set_tris_D(0b00000000); // Paramétrage du port D
set_tris_E(0b00000000);
data=0x01;
delay_ms(2000);
while(true)
{
i2c_start();
i2c_write(0x90); // Adresse
i2c_write(data++); // Data
i2c_stop();
delay_ms(100);
}
}
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Slave code
| Code: |
#include <18F452.h>
#fuses NOWDT,WDT128,HS, NOPROTECT, NOOSCSEN, BROWNOUT, BORV20, PUT, STVREN, NODEBUG, NOLVP, NOWRT, NOWRTD, NOWRTB, NOWRTC, NOCPD, NOCPB, NOEBTR, NOEBTRB
#use delay(clock=20000000)
#use i2c(SLAVE, ADDRESS=0x90, SCL=PIN_C3, SDA=PIN_C4, FAST=400000, FORCE_HW)
#use fast_io(A)
#use fast_io(B)
#use fast_io(C)
#use fast_io(D)
#use fast_io(E)
#include <LCD_nopnop.C>
int valeur1;
int valeur2;
#INT_SSP
void SSP_INT()
{
byte incoming,state;
state=i2c_isr_state();
if(state<0x80)
{
incoming=i2c_read(1);
if(state == 1) //First received byte is address
{
valeur1=incoming;
}
if(state == 2) //Second received byte is data
{
valeur2=incoming;
}
}
if (state>=0x80)
{
i2c_write(0x45);
}
}
void main()
{
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_wdt(WDT_OFF);
enable_interrupts(GLOBAL);
enable_interrupts(INT_SSP);
clear_interrupt(INT_SSP);
output_A(0);
output_B(0);
output_C(0);
output_E(0);
set_tris_A(0b00000001);
set_tris_B(0b10111111);
set_tris_C(0b10111011);
set_tris_E(0b00000100);
lcd_init(); // Init ecran LCD
valeur1=0;
valeur2=0;
while(true)
{
lcd_gotoxy(1,2);
printf(LCD_PUTC,"%x",valeur1);
lcd_gotoxy(4,2);
printf(LCD_PUTC,"%x",valeur2);
}
} |
_________________
made by www.nopnop.fr |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Sep 04, 2007 3:29 pm |
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Don't try to run the slave at 400 KHz. Change the i2c Master clock
speed to 100 KHz. |
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Nopnop
Joined: 10 Aug 2007
Posts: 7
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| Posted: Wed Sep 05, 2007 2:09 pm |
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Hi I have tried your advice with SLOW or FAST=100000.
The result is
00 00
01 00
02 00
03 00
…..
It is better but I don’t know why the data is first and address second. Normally it is the opposite.
_________________
made by www.nopnop.fr |
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Ttelmah
Guest
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| Posted: Wed Sep 05, 2007 2:23 pm |
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The address arrives when state==0. You are not printing this. Valeur2, remains '0', from when the chip woke up. You need:
| Code: |
if(state<0x80)
{
incoming=i2c_read(1);
if(state == 0) //First received byte is address
{
valeur1=incoming;
}
if(state == 1) //Second received byte is data - '1' = first data
{ //byte received.
valeur2=incoming;
}
}
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Nopnop
Joined: 10 Aug 2007
Posts: 7
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| Posted: Thu Sep 06, 2007 2:17 pm |
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Hi,
Thanks for your help
I have tried your solution but the result is
01 01
02 02
03 03
04 04
…….
Do you know why address does not appear perhaps the FORCE_HW parameter?
_________________
made by www.nopnop.fr |
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