engine-software/comms/Prev/communication/SlaveDuinoTest.ino
2022-08-07 14:39:16 -04:00

56 lines
1001 B
C++

#include <SPI.h>
char buf [100];
volatile byte pos;
volatile bool process_it;
void setup (void)
{
Serial.begin (115200); // debugging
// turn on SPI in slave mode
SPCR |= bit (SPE);
// have to send on master in, *slave out*
pinMode (MISO, OUTPUT);
// 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
// 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;
Serial.println (buf);
pos = 0;
process_it = false;
} // end of flag set
} // end of loop