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chienthanbka
Joined: 19 Mar 2016
Posts: 2
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| [SPI] Can't sent data from slave to master |
 Posted: Sat Mar 19, 2016 6:31 am |
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| Quote: | I want to test SPI communication using 2 pics 16f887, I want to send a byte to SLAVE, then send back a byte from slave to master.
- The data from master is successfully generated out (I'm not sure the slave received successfully or not)
- But the data from slave I tried to send back is not generated.
=> I attached the image of protus and the waveform on oscillator for your convenience of checking
Please help me by give me your idea and correct my program.
Thank you all in advance!
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[img] http://postimg.org/image/ygeugn4vd/ [/img]
| Code: |
#include <16f887.h>
#include <stdio.h>
#fuses INTRC_IO, NOWDT, PUT ,BROWNOUT, NOLVP
#use delay(clock=8000000)
#use rs232(baud=9600,xmit=PIN_C6,rcv=PIN_C7,stream=TERMINAL)
#define SPI_MODE_0_0 (SPI_L_TO_H | SPI_XMIT_L_TO_H) //SPI Mode 0
#define SPI_MODE_0_1 (SPI_L_TO_H) //SPI Mode 1
#define SPI_MODE_1_0 (SPI_H_TO_L) //SPI Mode 2
#define SPI_MODE_1_1 (SPI_H_TO_L | SPI_XMIT_L_TO_H) //SPI Mode 3
//#define CS PIN_C2
//#define DI PIN_C4
//#define DOUT PIN_C5
//#define CLK PIN_C3
void main ()
{
int8 data;
setup_spi(SPI_MASTER | SPI_MODE_0_0 | SPI_CLK_DIV_64);
set_tris_c(0b00010000);
output_bit(pin_c2,1); //pin c2 is the master pin connect to slave SS
data = 0xaa;
while (1){
output_bit(pin_c2,0);
// delay_us(10);
spi_write(data);
// delay_us(80);
output_bit(pin_c2,1);
delay_us(80); //give time for slave interrupt, usually >60
while(!spi_data_is_in());
output_bit(pin_c2,0);
spi_read(0);
output_bit(pin_c2,1);
delay_ms(100);
}
}
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| Code: |
#include <16f887.h>
#include <stdio.h>
#fuses INTRC_IO, NOWDT, PUT ,BROWNOUT, NOLVP
#use delay(clock=8000000)
#use rs232(baud=9600,xmit=PIN_C6,rcv=PIN_C7,stream=TERMINAL)
#define SPI_MODE_0_0 (SPI_L_TO_H | SPI_XMIT_L_TO_H) //SPI Mode 0
#define SPI_MODE_0_1 (SPI_L_TO_H) //SPI Mode 1
#define SPI_MODE_1_0 (SPI_H_TO_L) //SPI Mode 2
#define SPI_MODE_1_1 (SPI_H_TO_L | SPI_XMIT_L_TO_H) //SPI Mode 3
int data;
#int_ssp
void spi(void)
{
disable_interrupts(INT_SSP);
data = spi_read(0);//Vua nhan vua truyen.
// while(!spi_data_is_in())
spi_write(data);
enable_interrupts(INT_SSP);
}
void main ()
{
//SETUP_ADC_PORTS(NO_ANALOGS);
setup_spi(SPI_SLAVE | SPI_MODE_0_0);
clear_interrupt(INT_SSP);
enable_interrupts(INT_SSP);
enable_interrupts(GLOBAL);
output_high(pin_a5); //pin a5 is slave SS
while (1){
}
}
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asmboy
Joined: 20 Nov 2007
Posts: 2128
Location: albany ny
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| Posted: Sat Mar 19, 2016 7:01 am |
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when you have tried this in HARDWARE - why not come again?
the proteus isis "schematic" is woefully INCOMPLETE and would not work if it WAS hardware. the code you posted is irrelevant ( and it is flawed anyway)
but you ought to read this first:
http://www.ccsinfo.com/forum/viewtopic.php?t=47549
for proteus - try another forum where people are more apt to help with homework. |
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chienthanbka
Joined: 19 Mar 2016
Posts: 2
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| Posted: Sat Mar 19, 2016 7:31 am |
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Hi Asmboy,
First, thank you very much for your time.
| Quote: |
when you have tried this in HARDWARE - why not come again?
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I did not process on HARDWARE yet, just a simulation on PROTUS, did you see any problem in my code ? if not, then I will start checking protus issue or apply on hardware.
| Quote: |
the proteus isis "schematic" is woefully INCOMPLETE and would not work if it WAS hardware
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Would you please point out my woeful points ? sorry, i'm just a beginner, it will be very help for me later times.
| Quote: |
the code you posted is irrelevant ( and it is flawed anyway)
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I'm not so clear your idea, what is the irrelevance? what is your mean with "flawed anyway" ?
Thanks |
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asmboy
Joined: 20 Nov 2007
Posts: 2128
Location: albany ny
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| Posted: Sat Mar 19, 2016 8:23 am |
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1- your schematic has no power connections -woefully incomplete - no decoupling caps
2-proteus simulation is WORTHLESS and no serious programmer uses it for anything.
3-#use rs232 is missing ERRORS
4-set_tris is only for use with #use fastio
5- slave code has useless enable/disable commands -
6- SPI setup looks defective for both
7- the "oscilloscope" picture isn't worth the pixels it takes to show it.
you can't tell what is wrong when using proteus - that is the big problem... over and out |
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Mike Walne
Joined: 19 Feb 2004
Posts: 1785
Location: Boston Spa UK
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| Posted: Sat Mar 19, 2016 9:13 am |
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What you're being told is, if you ever get you're code to work in Proteus/ISIS, it's highly unlikely to work on real hardware.
There will be loads of faults (both hardware and software) and you'll have to start debugging from scratch all over again.
You're therefore better off starting with real hardware from the outset.
None of the regulars here will bother wasting their time on Proteus/ISIS.
They are usually more than willing to help you from the beginning.
We were all novices once and appreciated guidance from mentors.
Mike |
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asmboy
Joined: 20 Nov 2007
Posts: 2128
Location: albany ny
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| Posted: Sat Mar 19, 2016 10:27 am |
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what Mike is saying is this:
Take the trouble to "Build IT! And we will come "
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Ttelmah
Joined: 11 Mar 2010
Posts: 19338
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| Posted: Sat Mar 19, 2016 3:01 pm |
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As comments though, SS, is an input on the slave. It is defined in the hardware. You should not be outputting on it in the slave. The master _software_ pin, needs to connect to the slave _hardware_ pin. Then there needs to be time between sending a byte, and trying to read back. Understand INT_SSP occurs when the byte _finishes_ receipt. The master can't clock it back until after the slave has loaded it, so there has to be perhaps 20uSec delay after sending before trying to receive.
The point about Proteus, is you can get the whole project 'working' on this, and then when you switch to hardware find it doesn't work. Conversely you can have 'real' hardware projects that refuse to work in Proteus. So time trying to develop code in Proteus is basically wasted.
We see so many people not realising this, that the first line on seeing the word 'Proteus', is 'go away'..... |
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