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isikmurat06
Joined: 08 Jan 2011
Posts: 7
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| i2c --Master read from slave's analog input-- problem |
 Posted: Sun Jan 09, 2011 10:14 am |
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hi,
I have 3 pic16F877A. One of them is master and the others is slave.
The Slave pics read analog data from their own I/O.
The Master pic will read analog data from slave pics by i2c. And show it an LCD that is connected to the master pic.
I use 1k resistor to pull-up for SCL and SDA line
unfortunately, I even couldn't connect one slave to one master.
I don't know if there is any error with my codes or Proteus doesn't show anything. Please help...
MASTER CODE:
| Code: |
#include <16f877a.h>
#fuses HS,NOLVP,NOWDT,NOPROTECT
#use delay(clock=4000000)
#use I2C(FAST, SCL=PIN_C3, SDA=PIN_C4, FORCE_HW)
#define use_portb_lcd True
#include <lcd.c>
float data;
void main(void)
{
lcd_init();
set_tris_c(0xFF);
while(TRUE)
{
i2c_start();
delay_ms(2);
i2c_write(0xE0); //send the slave address
delay_ms(2);
i2c_write(0xE1); //send R/W bit for reading
delay_ms(2);
i2c_start(); //make the slave to send data
delay_ms(2);
data=i2c_read(); //Read the data
delay_ms(2);
i2c_stop();
printf(lcd_putc,"\f data=%f",data);
delay_ms(5000);
}
}
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SLAVE-1 CODE:
| Code: |
#include <16f877A.h>
#device adc=8
#fuses HS,NOLVP,NOWDT,NOPROTECT
#use delay(clock=4000000)
#use i2c(SLAVE, FAST, SCL=PIN_C3, SDA=PIN_C4, address=0xE0, FORCE_HW)
#use fast_io(c)
#use fast_io(d)
BYTE state;
int8 adc_result;
#INT_SSP //Interrupt for I2C activity
void sspinterupt()
{
disable_interrupts(INT_SSP);
state = i2c_isr_state();
if(state == 0x80) //master is requesting data
{
i2c_write (adc_result); //send requested data
}
}
void main(void)
{
setup_psp(PSP_DISABLED);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_CCP1(CCP_OFF);
setup_CCP2(CCP_OFF);
set_tris_c(0xFF);
enable_interrupts(INT_SSP);
enable_interrupts(GLOBAL);
setup_adc(adc_clock_div_32);
setup_adc_ports(all_analog);
while(TRUE)
{
set_adc_channel(0);
delay_us(10);
adc_result=read_adc();
delay_us(10);
enable_interrupts(INT_SSP);
}
} |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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isikmurat06
Joined: 08 Jan 2011
Posts: 7
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| Posted: Mon Jan 10, 2011 2:25 am |
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| I tried without any changes, but I couldn't make it work. So, I have made a little changes with your codes. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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isikmurat06
Joined: 08 Jan 2011
Posts: 7
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| Posted: Tue Jan 11, 2011 2:15 am |
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My proteus version is 7.6 sp2
CCS C version is 4.093 |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Jan 11, 2011 12:40 pm |
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I don't have Proteus, so I can't test it for you. I can't help you any more
on this problem. |
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matrix86
Joined: 15 Feb 2011
Posts: 2
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| Re: i2c --Master read from slave's analog input-- problem |
| Posted: Tue Feb 15, 2011 5:24 am |
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| isikmurat06 wrote: | hi,
I have 3 pic16F877A. One of them is master and the others is slave.
The Slave pics read analog data from their own I/O.
The Master pic will read analog data from slave pics by i2c. And show it an LCD that is connected to the master pic.
I use 1k resistor to pull-up for SCL and SDA line
unfortunately, I even couldn't connect one slave to one master.
I don't know if there is any error with my codes or Proteus doesn't show anything. Please help...
MASTER CODE:
| Code: |
#include <16f877a.h>
#fuses HS,NOLVP,NOWDT,NOPROTECT
#use delay(clock=4000000)
#use I2C(FAST, SCL=PIN_C3, SDA=PIN_C4, FORCE_HW)
#define use_portb_lcd True
#include <lcd.c>
float data;
void main(void)
{
lcd_init();
set_tris_c(0xFF);
while(TRUE)
{
i2c_start();
delay_ms(2);
i2c_write(0xE0); //send the slave address
delay_ms(2);
i2c_write(0xE1); //send R/W bit for reading
delay_ms(2);
i2c_start(); //make the slave to send data
delay_ms(2);
data=i2c_read(); //Read the data
delay_ms(2);
i2c_stop();
printf(lcd_putc,"\f data=%f",data);
delay_ms(5000);
}
}
|
SLAVE-1 CODE:
| Code: |
#include <16f877A.h>
#device adc=8
#fuses HS,NOLVP,NOWDT,NOPROTECT
#use delay(clock=4000000)
#use i2c(SLAVE, FAST, SCL=PIN_C3, SDA=PIN_C4, address=0xE0, FORCE_HW)
#use fast_io(c)
#use fast_io(d)
BYTE state;
int8 adc_result;
#INT_SSP //Interrupt for I2C activity
void sspinterupt()
{
disable_interrupts(INT_SSP);
state = i2c_isr_state();
if(state == 0x80) //master is requesting data
{
i2c_write (adc_result); //send requested data
}
}
void main(void)
{
setup_psp(PSP_DISABLED);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_CCP1(CCP_OFF);
setup_CCP2(CCP_OFF);
set_tris_c(0xFF);
enable_interrupts(INT_SSP);
enable_interrupts(GLOBAL);
setup_adc(adc_clock_div_32);
setup_adc_ports(all_analog);
while(TRUE)
{
set_adc_channel(0);
delay_us(10);
adc_result=read_adc();
delay_us(10);
enable_interrupts(INT_SSP);
}
} |
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you should write;
i2c_start();
i2c_write(0xe1);//master is requesting data from the slave
data=i2c_read(0);//to stop the reading from the slave NACK will be sent before stop
i2c_stop();
_________________
hayat cekilmeye deger |
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matrix86
Joined: 15 Feb 2011
Posts: 2
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| Re: i2c --Master read from slave's analog input-- problem |
| Posted: Tue Feb 15, 2011 5:30 am |
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My problem is to read data from 3 different slaves. When I request data from one slave it responds correctly and there is no problem but then when I want to request datas from other slaves one by one, they do not respond. I did not understand why.
_________________
hayat cekilmeye deger |
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