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Topic: SPI interface with other board_AVR_ESK1100 or among Arduino itself (Read 11743 times) previous topic - next topic

ranjeetray


I can't make out anything from the scope screen shots, there's obviously something happening though.

Tell you what I'll do, against my better judgement I'll try to write you some code for both ends based on what I think you want to do.

______
Rob


Thank You.

It will be really a great help for me.

Graynomad

Here's some code. I took the razor to what you had and removed everything not required to prove the concept. Hopefully I didn't go too far. The master could still be a lot smaller.

Master

Code: [Select]
//Master sending data
#include <SPI.h>// include the SPI library:
#define SS_PIN   10

int command_array[] = {0x04, 0x06, 0x08, 0x0A};
int returned_data[4];

void setup() {
 
  pinMode (SS_PIN, OUTPUT);// set the spi_data_pin as an output:

  Serial.begin(115200);
 
  SPI.begin();
  SPI.setDataMode(SPI_MODE2);
  SPI.setClockDivider(SPI_CLOCK_DIV64) ;
  SPI.setBitOrder(LSBFIRST);

}

void loop() {
   
    digitalWrite(SS_PIN,LOW);
    SPI.transfer(command_array[0]);       // send command
    delay(1);                             // give the slave some time
    returned_data[0] = SPI.transfer(0);   // get response
    digitalWrite(SS_PIN,HIGH);

    digitalWrite(SS_PIN,LOW);
    delay(1);
    SPI.transfer(command_array[1]);
    returned_data[1] = SPI.transfer(0);
    digitalWrite(SS_PIN,HIGH);

    digitalWrite(SS_PIN,LOW);
    delay(1);
    SPI.transfer(command_array[2]);
    returned_data[2] = SPI.transfer(0);
    digitalWrite(SS_PIN,HIGH);

    digitalWrite(SS_PIN,LOW);
    delay(1);
    SPI.transfer(command_array[3]);
    returned_data[3] = SPI.transfer(0);
    digitalWrite(SS_PIN,HIGH);

    Serial.print (returned_data[0]);
    Serial.print (',');
    Serial.print (returned_data[1]);
    Serial.print (',');
    Serial.print (returned_data[2]);
    Serial.print (',');
    Serial.println (returned_data[3]);
 
}


Slave
Code: [Select]

byte response_data[] = {-1,-1,-1,-1,'4',-1,'6',-1,'8',-1,'A'};

void setup (void) {
 
  pinMode(MISO, OUTPUT); // have to send on master in, *slave out*
  SPCR |= _BV(SPE);   // turn on SPI in slave mode
  SPCR |= _BV(SPIE);  // turn on interrupts



void loop () {}

ISR (SPI_STC_vect) {
  byte command = SPDR;

  SPDR = response_data[command];




See if that does anything useful.

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

Nick Gammon


Hi...!!

I am reading http://www.gammon.com.au/spi again and again and trying to grasp SPI, but not getting expected results.

Can we write the codes like this, are these correct codes for mater and slave
...
Slave receiving data from master then sending the data back to master, is it right.

Code: [Select]

...

// SPI interrupt routine
ISR (SPI_STC_vect)
{
 c = SPDR;
 
if(c == 0x04)
 {
   digitalWrite(SS, LOW);
 SPI.transfer(dat[0]);
 SPI.transfer(dat[1]);
  digitalWrite(SS, HIGH);
 
  digitalWrite(SS, LOW);
 SPI.transfer(dat[2]);
 SPI.transfer(dat[3]);
  digitalWrite(SS, HIGH);
 
  digitalWrite(SS, LOW);
 SPI.transfer(dat[4]);
 SPI.transfer(dat[5]);
  digitalWrite(SS, HIGH);
}

 else if(c == 0x06)
 {
  digitalWrite(SS, LOW);
 SPI.transfer(dat[6]);
 SPI.transfer(dat[7]);
  digitalWrite(SS, HIGH);
 
  digitalWrite(SS, LOW);
 SPI.transfer(dat[8]);
 SPI.transfer(dat[9]);
  digitalWrite(SS, HIGH);
 
  digitalWrite(SS, LOW);
 SPI.transfer(dat[10]);
 SPI.transfer(dat[11]);
  digitalWrite(SS, HIGH);
}
 else
SPDR = 0x00;    // what to return to the master



}  // end of interrupt service routine (ISR) SPI_STC_vect
...



Look, ranjeetray, you are just ignoring everything I am saying. I said this:



Can we do like this, after receiving data can we check(if condition) data and then send back data to master like this.


I really don't know what you are trying to do. You are doing an SPI.transfer in the middle of the ISR?

You send back data to the master by assigning to SPDR in the interrupt service routine. No other way. What are you thinking?


You do not use SPI.transfer in the ISR. Do you have trouble understanding that?

You are ignoring me, you are just making stuff up, and then taking screen shots of the scope output. It won't work.

Graynomad has offered to write an example but that won't help if you don't make an attempt to understand things. Don't just copy and paste and hope for the best.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

ranjeetray

#93
Nov 17, 2012, 08:35 am Last Edit: Nov 17, 2012, 08:47 am by ranjeetray Reason: 1

Here's some code. I took the razor to what you had and removed everything not required to prove the concept. Hopefully I didn't go too far. The master could still be a lot smaller.

Master

Code: [Select]
//Master sending data
#include <SPI.h>// include the SPI library:
#define SS_PIN   10

int command_array[] = {0x04, 0x06, 0x08, 0x0A};
int returned_data[4];

void setup() {
 
 pinMode (SS_PIN, OUTPUT);// set the spi_data_pin as an output:

 Serial.begin(115200);
 
 SPI.begin();
 SPI.setDataMode(SPI_MODE2);
 SPI.setClockDivider(SPI_CLOCK_DIV64) ;
 SPI.setBitOrder(LSBFIRST);

}

void loop() {
   
   digitalWrite(SS_PIN,LOW);
   SPI.transfer(command_array[0]);       // send command
   delay(1);                             // give the slave some time
   returned_data[0] = SPI.transfer(0);   // get response
   digitalWrite(SS_PIN,HIGH);

   digitalWrite(SS_PIN,LOW);
   delay(1);
   SPI.transfer(command_array[1]);
   returned_data[1] = SPI.transfer(0);
   digitalWrite(SS_PIN,HIGH);

   digitalWrite(SS_PIN,LOW);
   delay(1);
   SPI.transfer(command_array[2]);
   returned_data[2] = SPI.transfer(0);
   digitalWrite(SS_PIN,HIGH);

   digitalWrite(SS_PIN,LOW);
   delay(1);
   SPI.transfer(command_array[3]);
   returned_data[3] = SPI.transfer(0);
   digitalWrite(SS_PIN,HIGH);

   Serial.print (returned_data[0]);
   Serial.print (',');
   Serial.print (returned_data[1]);
   Serial.print (',');
   Serial.print (returned_data[2]);
   Serial.print (',');
   Serial.println (returned_data[3]);
 
}


Slave
Code: [Select]

byte response_data[] = {-1,-1,-1,-1,'4',-1,'6',-1,'8',-1,'A'};

void setup (void) {
 
 pinMode(MISO, OUTPUT); // have to send on master in, *slave out*
 SPCR |= _BV(SPE);   // turn on SPI in slave mode
 SPCR |= _BV(SPIE);  // turn on interrupts

}  

void loop () {}

ISR (SPI_STC_vect) {
 byte command = SPDR;

 SPDR = response_data[command];

}  


See if that does anything useful.

______
Rob


Code: [Select]

//Master sending data
#include <SPI.h>// include the SPI library:
#define SS_PIN   10

int command_array[] = {0x04, 0x06, 0x08, 0x0A};
int returned_data[4];

void setup() {
 
 pinMode (SS_PIN, OUTPUT);// set the spi_data_pin as an output:

 Serial.begin(115200);
 
 SPI.begin();
 SPI.setDataMode(SPI_MODE2);
 SPI.setClockDivider(SPI_CLOCK_DIV64) ;
 SPI.setBitOrder(LSBFIRST);

}

void loop() {
   
   digitalWrite(SS_PIN,LOW);
   SPI.transfer(command_array[0]);       // send command
   delay(1);                             // give the slave some time
   returned_data[0] = SPI.transfer(0);   // get response
   digitalWrite(SS_PIN,HIGH);

   digitalWrite(SS_PIN,LOW);
   delay(1);
   SPI.transfer(command_array[1]);
   returned_data[1] = SPI.transfer(0);
   digitalWrite(SS_PIN,HIGH);

   digitalWrite(SS_PIN,LOW);
   delay(1);
   SPI.transfer(command_array[2]);
   returned_data[2] = SPI.transfer(0);
   digitalWrite(SS_PIN,HIGH);

   digitalWrite(SS_PIN,LOW);
   delay(1);
   SPI.transfer(command_array[3]);
   returned_data[3] = SPI.transfer(0);
   digitalWrite(SS_PIN,HIGH);

   Serial.print (returned_data[0]);
   Serial.print (',');
   Serial.print (returned_data[1]);
   Serial.print (',');
   Serial.print (returned_data[2]);
   Serial.print (',');
   Serial.println (returned_data[3]);
 
}




With the following code, attached image 2 and TEK0002 are the output at Master Serial Monitor and on Oscilloscope:
Code: [Select]

#include "pins_arduino.h"
#include <SPI.h>

#define size_data 4  // is there 4 bytes? if not change this and the arrays.

byte send_04_data[size_data] = {1,2,3,7}; // you fill in the numbers
byte send_06_data[size_data] = {3,8,7,9};
byte * data_ptr;
int byte_count = 0;
void setup (void)
{
 
 // have to send on master in, *slave out*
 pinMode(MISO, OUTPUT);
 SPI.setBitOrder(MSBFIRST);
 SPI.setDataMode (SPI_MODE2);
 SPI.setClockDivider(SPI_CLOCK_DIV64) ;

 // turn on SPI in slave mode
 SPCR |= _BV(SPE);

 // turn on interrupts
 SPCR |= _BV(SPIE);
 
// disable timer interrupts
 TIMSK0 = 0;
 
}
ISR (SPI_STC_vect) {
 byte c = SPDR;
 if (byte_count == 0)
 {
   
     data_ptr = (c == 0x04) ? send_04_data : send_06_data;
 
 SPDR = *(data_ptr + byte_count);
 byte_count++; }  
 else
 
 {
   SPDR = 0;
 
 }
 if (byte_count = size_data)
 byte_count = 0;
}
void loop (void)
{

}  // end of loop


With the following code image 3 and TEK0006 are  output:
Code: [Select]

#include "pins_arduino.h"
#include <SPI.h>
byte response_data[] = {1,2,-1,3,'4',-1,'6',-1,'8',-1,'A'};
void setup (void)
{
 
 // have to send on master in, *slave out*
 pinMode(MISO, OUTPUT);
 SPI.setBitOrder(MSBFIRST);
 SPI.setDataMode (SPI_MODE2);
 SPI.setClockDivider(SPI_CLOCK_DIV64) ;
 // turn on SPI in slave mode
 SPCR |= _BV(SPE);
 // turn on interrupts
 SPCR |= _BV(SPIE);
 // disable timer interrupts
 TIMSK0 = 0;

}

void loop (void)
{

}  // end of loop

ISR (SPI_STC_vect) {

 byte command = SPDR;

 SPDR = response_data[command];

}

But Slave is not sending data back properly.


Graynomad

Do you deliberately not use the code provided to wind us up or what? Why did you change the array and put all the SPI setup code back in?

Use the slave code I posted. It may not be correct but it's a lot better than what you have I think.

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

Nick Gammon

Quote
Code: [Select]
if (byte_count = size_data)
  byte_count = 0;


I think it's a troll.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

AWOL

I've worn a groove in my tablet's screen scrolling through this thread.
Nick, you deserve a medal.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

ranjeetray


I've worn a groove in my tablet's screen scrolling through this thread.
Nick, you deserve a medal.



I appreciate for your effort.

ranjeetray


I've worn a groove in my tablet's screen scrolling through this thread.
Nick, you deserve a medal.


Hi...!!!

I have tried all the possible combinations , Slave is not able to send back data to master for each if conditions.

Code: [Select]

#include "pins_arduino.h"

#include <SPI.h>

#define SS 10

int dat[24] = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14};

byte c;

int m, n ;

void setup (void)

{

  // have to send on master in, *slave out*

  pinMode(MISO, OUTPUT);

  SPI.setBitOrder(MSBFIRST);

  SPI.setDataMode (SPI_MODE2);

  SPI.setClockDivider(SPI_CLOCK_DIV64) ;



  // turn on SPI in slave mode

  SPCR |= _BV(SPE);



  // turn on interrupts

  SPCR |= _BV(SPIE);



// disable timer interrupts

  TIMSK0 = 0;



}  // end of setup





// SPI interrupt routine

ISR (SPI_STC_vect)

{

  c = SPDR;

  if(c == 0x00)

{

  SPDR = 0x01;

}

  else if(c == 0x06)

{



  SPDR = 0x02;

}

  else if(c == 0x08)

{



  SPDR = 0x03;

}

   else if(c == 0x0A)

{



  SPDR = 0x07;

}



else

SPDR = 0;    // what to return to the master



}  // end of interrupt service routine (ISR) SPI_STC_vect



void loop (void)

{



}  // end of loop




Nick Gammon

What is the master code? And it might be quicker to just index into an array.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

Nick Gammon

Code: [Select]

int dat[24] = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14};


What is the point of this?
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

ranjeetray


Code: [Select]

int dat[24] = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14};


What is the point of this?


Instead of sending SPDR = 0x01 or, data I was trying to send SPDR = dat[0]; but that also dint work.

ranjeetray

#102
Nov 19, 2012, 07:55 am Last Edit: Nov 19, 2012, 08:09 am by ranjeetray Reason: 1
Code: [Select]
[quote author=Nick Gammon link=topic=120454.msg1001647#msg1001647 date=1353307358]
What is the master code? And it might be quicker to just index into an array.
[/quote]
Master code on AVR:


[code]
/**
* \file

* Include header files for all drivers that have been imported from
* AVR Software Framework (ASF).
*/
#include <asf.h>
#include <avr32/io.h>
#include "pm.h"
#include "delay.h"

int16_t *readData,i;
unsigned int timeout = 1500;
int16_t cmdAddr[30] = {0x0400,0x0600,0x0800,0x0A00,0x0C00,0x0E00,0x1000,0x1200,0x1400};
//int16_t cmdAddr[30] = {0x04, 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x08,0x00,0x00, 0x00, 0x0A,0x00, 0x00, 0x00,0x0C, 0x00, 0x00, 0x00, 0x0E, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00};
int main (void)
{
pm_switch_to_osc0(&AVR32_PM,12000000,2048); // Switch the main clock to the external oscillator 0
delay_init(12000000);
// delay_ms(20); // busy wait for 20ms

AVR32_GPIO.port[0].gperc = 1 << 10; // A peripheral function controls the corresponding pin
AVR32_GPIO.port[0].gperc = 1 << 11; // A peripheral function controls the corresponding pin
AVR32_GPIO.port[0].gperc = 1 << 12; // A peripheral function controls the corresponding pin
AVR32_GPIO.port[0].gperc = 1 << 13; // A peripheral function controls the corresponding pin
AVR32_GPIO.port[0].pmr0c = 1 << 10; // To select the peripheral function A
AVR32_GPIO.port[0].pmr1c = 1 << 10; // To select the peripheral function A
AVR32_GPIO.port[0].pmr0c = 1 << 11; // To select the peripheral function A
AVR32_GPIO.port[0].pmr1c = 1 << 11; // To select the peripheral function A
AVR32_GPIO.port[0].pmr0c = 1 << 12; // To select the peripheral function A
AVR32_GPIO.port[0].pmr1c = 1 << 12; // To select the peripheral function A
AVR32_GPIO.port[0].pmr0c = 1 << 13; // To select the peripheral function A
AVR32_GPIO.port[0].pmr1c = 1 << 13; // To select the peripheral function A

AVR32_SPI0.MR.mstr = 1; // SPI operates in MASTER mode
AVR32_SPI0.MR.modfdis = 0; // Mode Fault Detection disabled
AVR32_SPI0.MR.llb = 0; // Local loop path disabled
AVR32_SPI0.MR.ps = 0; // Fixed peripheral is selected
AVR32_SPI0.MR.pcsdec = 0 ; // The chip selects are directly connected to a peripheral device
AVR32_SPI0.MR.dlybcs = 0; // Delay between chip selects

AVR32_SPI0.MR.pcs = 0xF; // Peripheral chip select disable
AVR32_SPI0.CSR0.scbr = 0x28; // Serial Clock Baud Rate initialized to 40
AVR32_SPI0.CSR0.dlybs = 0x0a; // Delay before serial clock signal (SPCK)
AVR32_SPI0.CSR0.dlybct = 0x12; // Delay between consecutive transfers
AVR32_SPI0.CSR0.csaat = 1; // Chip Select Active After Transfer

AVR32_SPI0.CSR0.cpol = 1 ; // Clock polarity  
AVR32_SPI0.CSR0.ncpha = 0 ; // Clock phase  
   AVR32_SPI0.CSR0.bits =0x8; // Number of data bits transferred.

while(1)
{
readData = 0x500;
i = 0;
AVR32_SPI0.CR.spien = 1; // Enables the SPI to transfer and receive data

while(i!=9)
{
AVR32_SPI0.MR.pcs = 0xE; // Peripheral Chip Select (CSR0) enable
while (AVR32_SPI0.SR.tdre != 1); // Transmit Data Register Empty
AVR32_SPI0.TDR.td = cmdAddr[i]; // send command address to TDR register
   while(AVR32_SPI0.SR.tdre!=1); // Transmit data ready empty status
AVR32_SPI0.TDR.td = 0x0000;
while(AVR32_SPI0.SR.rdrf!=1); // Read data register full status
readData[i] = AVR32_SPI0.RDR.rd;    // Store read data into an array
i++;
AVR32_SPI0.MR.pcs = 0xF;            // Disable the peripheral chip select (CSR0)
  delay_ms(2);
  }

AVR32_SPI0.CR.spidis = 1; // Disables the SPI, it finishes its transfer
delay_ms(20);                       // busy wait for 20ms
}
while(1);
}



And Master AVR is reading just FFFFFFFFFFFFFFFFF , what could be the reason.




Master code on Arduino
Code: [Select]

//Master sending data
#include <SPI.h>// include the SPI library:
#define SS_PIN   10

int command_array[] = {0x04, 0x06, 0x08, 0x0A};
int returned_data[4];

void setup() {
 
 pinMode (SS_PIN, OUTPUT);// set the spi_data_pin as an output:

 Serial.begin(115200);
 
 SPI.begin();
 SPI.setDataMode(SPI_MODE2);
 SPI.setClockDivider(SPI_CLOCK_DIV64) ;
 SPI.setBitOrder(LSBFIRST);

}

void loop() {
   
   digitalWrite(SS_PIN,LOW);
   SPI.transfer(command_array[0]);       // send command
   //delay(1);                             // give the slave some time
   returned_data[0] = SPI.transfer(0);   // get response
   digitalWrite(SS_PIN,HIGH);

   digitalWrite(SS_PIN,LOW);
   //delay(1);
   SPI.transfer(command_array[1]);
   returned_data[1] = SPI.transfer(0);
   digitalWrite(SS_PIN,HIGH);

   digitalWrite(SS_PIN,LOW);
   //delay(1);
   SPI.transfer(command_array[2]);
   returned_data[2] = SPI.transfer(0);
   digitalWrite(SS_PIN,HIGH);

   digitalWrite(SS_PIN,LOW);
   //delay(1);
   SPI.transfer(command_array[3]);
   returned_data[3] = SPI.transfer(0);
   digitalWrite(SS_PIN,HIGH);

   Serial.print (returned_data[0]);
   Serial.print (',');
   Serial.print (returned_data[1]);
   Serial.print (',');
   Serial.print (returned_data[2]);
   Serial.print (',');
   Serial.println (returned_data[3]);
 
}




Master code on Arduino Again
Code: [Select]

//Master Program
#include <SPI.h>// include the SPI library:
#define SCK_PIN   13
#define MISO_PIN  12
#define MOSI_PIN  11

const int spidata = 10;//Pin 11 is data(MOSI) and pin 13 SCK ,set pin 10(SS) as the slave select for the digital pot:
int array[30] = {0x04, 0x00, 0x00, 0x00,  0x06, 0x00,0x00, 0x00,  0x08,0x00, 0x00, 0x00, 0x0A, 0x00, 0x00, 0x00};
int chr;

void setup() {
 
 pinMode (spidata, OUTPUT);// set the spi_data_pin as an output:
 
 SPI.begin();// initialize SPI:
 Serial.begin(115200);
 SPI.setDataMode(SPI_MODE2);
 SPI.setClockDivider(SPI_CLOCK_DIV64) ;
 SPI.setBitOrder(LSBFIRST);
 digitalWrite(spidata,LOW);

}

void loop() {
 int data[10];
 char ch;


   //delay(14);
  digitalWrite(spidata,LOW);
  SPI.transfer(array[0]);
  //delay(1);
  SPI.transfer(array[1]);
 // delay(1);
  digitalWrite(spidata,HIGH);
   //delay(14);
 
  digitalWrite(spidata,LOW);
  SPI.transfer(array[2]);
  //delay(1);
  SPI.transfer(array[3]);
 // delay(1);
  digitalWrite(spidata,HIGH);
  // delay(14);
 
  digitalWrite(spidata,LOW);
  SPI.transfer(array[4]);
  //delay(1);
  SPI.transfer(array[5]);
  //delay(1);
  digitalWrite(spidata,HIGH);
   //delay(1);
 
  digitalWrite(spidata,LOW);
  SPI.transfer(array[6]);
  //delay(1);
  SPI.transfer(array[7]);
 // delay(1);
  digitalWrite(spidata,HIGH);
 
    digitalWrite(spidata,LOW);
  SPI.transfer(array[8]);
// delay(1);
  SPI.transfer(array[9]);
  //delay(1);
  digitalWrite(spidata,HIGH);
 
     digitalWrite(spidata,LOW);
  SPI.transfer(array[10]);
// delay(1);
  SPI.transfer(array[11]);
 // delay(1);
  digitalWrite(spidata,HIGH);
 //delay(1);
 
    digitalWrite(spidata,LOW);
  SPI.transfer(array[12]);
  //delay(1);
  SPI.transfer(array[13]);
 // delay(1);
  digitalWrite(spidata,HIGH);
  // delay(14);
 
  digitalWrite(spidata,LOW);
  SPI.transfer(array[14]);
  //delay(1);
  SPI.transfer(array[15]);
 // delay(1);
  digitalWrite(spidata,HIGH);
  // delay(14);
 
  digitalWrite(spidata,LOW);
  SPI.transfer(array[16]);
  //delay(1);
  SPI.transfer(array[17]);
 // delay(1);
  digitalWrite(spidata,HIGH);
  //delay(14);
 
    digitalWrite(spidata,LOW);
  SPI.transfer(array[18]);
  //delay(1);
  SPI.transfer(array[19]);
  //delay(1);
  digitalWrite(spidata,HIGH);
 
     digitalWrite(spidata,LOW);
  SPI.transfer(array[20]);
  //delay(1);
  SPI.transfer(array[21]);
 // delay(1);
  digitalWrite(spidata,HIGH);
 
   digitalWrite(spidata,LOW);
  SPI.transfer(array[22]);
// delay(1);
  SPI.transfer(array[23]);
 // delay(1);
  digitalWrite(spidata,HIGH);
 //  delay(14);
   }



Slave code on Arduino
Code: [Select]

//Slave Code
#include "pins_arduino.h"
#include <SPI.h>
#define SS 10
int dat[24] = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14};
byte c;
int m, n ;
void setup (void)
{
 // have to send on master in, *slave out*
 pinMode(MISO, OUTPUT);
 SPI.setBitOrder(MSBFIRST);
 SPI.setDataMode (SPI_MODE2);
 SPI.setClockDivider(SPI_CLOCK_DIV64) ;

 // turn on SPI in slave mode
 SPCR |= _BV(SPE);

 // turn on interrupts
 SPCR |= _BV(SPIE);
 
// disable timer interrupts
 TIMSK0 = 0;
 
}  // end of setup


// SPI interrupt routine
ISR (SPI_STC_vect)
{
 c = SPDR;
 if(c == 0x04)
{
 SPDR = 0x01;
}
 else if(c == 0x06)
{

 SPDR = 0x02;
}
 else if(c == 0x08)
{

 SPDR = 0x03;
}
  else if(c == 0x0A)
{

 SPDR = 0x07;
}

//else
//SPDR = 0;    // what to return to the master

}  // end of interrupt service routine (ISR) SPI_STC_vect

void loop (void)
{

}  // end of loop


Exceeding the 9500 charecters.

[/code]

ranjeetray

#103
Nov 19, 2012, 08:01 am Last Edit: Nov 19, 2012, 08:03 am by ranjeetray Reason: 1

What is the master code? And it might be quicker to just index into an array.


Other Slave codes are:

Code: [Select]

#include <SPI.h>
#define MAX_BYTES 4  // is there 4 bytes? if not change this and the arrays.

byte cmd_04_data[MAX_BYTES] = {1,2,3,4}; // you fill in the numbers
byte cmd_06_data[MAX_BYTES] = {5,6,7,8};
byte * data_ptr;
int byte_count = 0;
void setup (void)
{
 
 // have to send on master in, *slave out*
 pinMode(MISO, OUTPUT);
 SPI.setBitOrder(MSBFIRST);
 SPI.setDataMode (SPI_MODE2);
 SPI.setClockDivider(SPI_CLOCK_DIV64) ;

 // turn on SPI in slave mode
 SPCR |= _BV(SPE);

 // turn on interrupts
 SPCR |= _BV(SPIE);
 
// disable timer interrupts
 TIMSK0 = 0;
 
}
ISR (SPI_STC_vect) {
 byte c = SPDR;
 if (byte_count == 0) {
     // set a pointer to one or other array based on the byte just received
     data_ptr = (c == 0x04) ? cmd_04_data : cmd_06_data;
 }
 SPDR = *(data_ptr + byte_count);
 byte_count++;  
 if (byte_count = MAX_BYTES) byte_count = 0;
}  
void loop (void)
{

}  // end of loop


Code: [Select]

byte response_data[] = {-1,-1,-1,-1,'4',-1,'6',-1,'8',-1,'A'};

void setup (void) {
 
  pinMode(MISO, OUTPUT); // have to send on master in, *slave out*
  SPCR |= _BV(SPE);   // turn on SPI in slave mode
  SPCR |= _BV(SPIE);  // turn on interrupts



void loop () {}

ISR (SPI_STC_vect) {
  byte command = SPDR;

  SPDR = response_data[command];




Nick Gammon

Quote
Master code on Arduino
...
Master code on Arduino Again
...
Other Slave codes are:


What?
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

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