i m using Db410c as a master and arduino mega as a slave here is my screenshot
actually master sends some random values with actual data
arduino mega as a slave
#include <SPI.h>
#include <stdlib.h>
char buf [100];
volatile byte pos;
volatile boolean process_it;
void setup (void)
{
//Start the Serial for the debugging
Serial.begin (115200);
// have to send on master in, slave out
pinMode(MISO, OUTPUT);
pinMode(53,INPUT);
//Setting up the LED pin as OUTPUT
pinMode(7,OUTPUT);
pinMode(6,OUTPUT);
// turn on SPI in slave mode
SPCR |= _BV(SPE);
// get ready for an interrupt
pos = 0; // buffer empty
process_it = false;
// now turn on interrupts
SPI.attachInterrupt();
} // end of setup
// SPI interrupt routine
ISR (SPI_STC_vect)
{
byte c = SPDR; // grab byte from SPI Data Register
SPDR=0;
if(digitalRead(53)==0){
// add to buffer if room
if (pos < sizeof buf)
{
buf [pos++] = c;
// example: newline means time to process buffer
if (c == '\n')
process_it = true;
} // end of room available
}
} // end of interrupt routine SPI_STC_vect
// main loop - wait for flag set in interrupt routine
void loop (void)
{
if (process_it)
{
buf [pos] = 0;
int buff = atoi(buf);
Serial.println (buff);
switch(buff){
case 10:
digitalWrite(6,HIGH);
digitalWrite(7,LOW);
break;
case 11:
digitalWrite(6,LOW);
digitalWrite(7,HIGH);
break;
}
pos = 0;
process_it = false;
} // end of flag set
}
