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pcm_shahid
Joined: 11 Oct 2018 Posts: 2
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SPI Problem |
Posted: Tue Feb 05, 2019 3:38 pm |
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I send data to slave and slave is received perfect, but when slave is send
back same data master is not received data. Please help seniors.
Master Code................
Code: |
#include <16F887.h>
#device ADC=10
#use delay(internal=4000000)
#FUSES NOWDT //No Watch Dog Timer
#FUSES PROTECT //Code protected from reads
#FUSES NOBROWNOUT //No brownout reset
#FUSES BORV21 //Brownout reset at 2.1V
#FUSES WRT_1000 //Program Memory Write Protected from 0 to 0x0FFF
//#include <STRING.H>
// #include <STDLIB.H>
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
//#use rs232(baud=9600, xmit=PIN_c6, rcv=PIN_c7,parity=N,bits=8 )
//#use rs232(baud=9600, xmit=PIN_a7, rcv=PIN_a6,parity=N,bits=8 )
#use fast_io(a)
#use fast_io(b)
#use fast_io(c)
#use fast_io(d)
#use fast_io(e)
#byte porta=0x05
#byte portb=0x06
#byte portc=0x07
#byte portd=0x08
#define LCD_RS_PIN PIN_d0
#define LCD_RW_PIN PIN_d1
#define LCD_ENABLE_PIN PIN_d2
//#define use_portd_lcd TRUE
#include <lcd.c>
#define cs pin_c2
#define up pin_A1
#define dn pin_A2
//#define SS PIN_B3
#use spi(FORCE_SW, BITS=8, stream=SPI_STREAM)
#use spi(master,ENABLE=pin_c2,spi1,mode=0,bits=8,stream=SPI_Max31856)
#define spi_xfer_31856(x) spi_xfer(SPI_Max31856, x,8)
int8 address,data;
int8 value_up=0x04,value_dn=0x09;
//===============================
void write_spi(int8 address)
{
// address=spi_xfer_31856(address);
// data=spi_xfer_31856(data);
data=spi_xfer_31856(address);
//spi_xfer_31856(data);
delay_ms(2);
printf("\faddress=%X data=%X\r\n",address ,data );
}
//=============================
//==============================
void main()
{
set_tris_a(0xff); output_a(0x00);
set_tris_b(0x02); output_b(0x00);
set_tris_c(0x10); output_c(0x00);
set_tris_d(0x00); output_d(0x00);
set_tris_e(0xff); output_e(0x00);
spi_xfer_31856(0x00);
lcd_init();
printf(lcd_putc,"\fSPI TEST MASTER2 ");
//enable_interrupts(INT_SSP);
enable_interrupts(GLOBAL);
while (TRUE)
{
if(!input(up)){write_spi(0x01);}
if(!input(dn)){write_spi(0x02);}
}
}
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SLAVE Code.................
Code: |
#include <16F887.h>
#device ADC=10
#use delay(internal=4000000)
#FUSES NOWDT //No Watch Dog Timer
#FUSES PROTECT //Code protected from reads
#FUSES NOBROWNOUT //No brownout reset
#FUSES BORV21 //Brownout reset at 2.1V
#FUSES WRT_1000 //Program Memory Write Protected from 0 to 0x0FFF
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
//#use rs232(baud=9600, xmit=PIN_c6, rcv=PIN_c7,parity=N,bits=8 )
//#use rs232(baud=9600, xmit=PIN_a7, rcv=PIN_a6,parity=N,bits=8 )
#use fast_io(a)
#use fast_io(b)
#use fast_io(c)
#use fast_io(d)
#use fast_io(e)
#byte porta=0x05
#byte portb=0x06
#byte portc=0x07
#byte portd=0x08
#define LCD_RS_PIN PIN_B0
#define LCD_RW_PIN PIN_B1
#define LCD_ENABLE_PIN PIN_B2
#define use_portb_lcd TRUE
#include <lcd.c>
#define cs pin_c2
#use spi(FORCE_SW, BITS=8, stream=SPI_STREAM)
#use spi(slave, spi1,mode=0,bits=8,stream=SPI_1)
#define spi_xfer_31856(x) spi_xfer(SPI_1, x,8)
//===============================
byte read_spi(int8 data)
{
int8 data_in;
data_in=spi_xfer_31856(data_in);
//if( data_in==0x09)spi_xfer_31856( 0x55);
//if( data_in==0x04)spi_xfer_31856( 0x46);
//spi_xfer_31856( data_in);
/*
SPI_XFER_9356(0x18);
SPI_XFER_9356(address);
data=SPI_XFER_9356(0);
*/
return(data_in);
}
//==============================
void main()
{
set_tris_a(0x7f); output_a(0x00);
set_tris_b(0x02); output_b(0x00);
set_tris_c(0x1c); output_c(0x00);
set_tris_d(0x00); output_d(0x00);
set_tris_e(0xff); output_e(0x00);
lcd_init();
printf(lcd_putc,"\fSPI TEST SLAVE2 ");
int8 address,data;
while (TRUE)
{
if(!input(cs)){
address = read_spi(spi_data_is_in());
data = read_spi(spi_data_is_in());
if(address==0x01 ){spi_xfer_31856( 0x04);output_high(pin_d0);output_low(pin_d1);}
if(address==0x02 ){spi_xfer_31856( 0x09);output_high(pin_d1);output_low(pin_d0);}
lcd_gotoxy(1,2);
printf(lcd_putc,"adres=%X data=%x ",address,data);
data=0;
}
}
} |
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Mike Walne
Joined: 19 Feb 2004 Posts: 1785 Location: Boston Spa UK
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Posted: Tue Feb 05, 2019 4:24 pm |
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Simplify your code to make it easier to read.
Get rid of anything which is not used, remove all the commented out lines.
Provide comments on what is supposed to happen.
Don't make us work it out, we've all got better things to do.
Mike |
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Ttelmah
Joined: 11 Mar 2010 Posts: 19496
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Posted: Wed Feb 06, 2019 12:35 am |
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These lines:
address = read_spi(spi_data_is_in());
are complete nonsense.
You are trying to clock 'back' to the master, the TRUE/FALSE value
returned by the test 'spi_data_is_in'. Why?.
Then you read a value from the SPI, when you send an address.
You have to understand that SPI always responds one byte 'behind'.
THe sequence would need to be to send the adddress, then pause
(to allow time for the slave to load the reply), then clock out a 'dummy'
byte which returns the reply from the slave. The slave can only
respond.
So:
Master sends byte
Slave receives this and loads reply
Master sends another byte and received the byte from the slave. |
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