Generating PWM with TIMER2 ATMega328P

[Cantafford]

Hello,

I have connected 2 ATMEGA328P's with SPI communication one as master one as slave. On the master MCU I have also attached a keypad. I want to read a key from that keypad and send it via SPI to the slave. I will use a test-led which will light up when the value of the key pressed is 0. I have tested the interfacing of the keypad. It works fine.

Should be simple however I cannot seem to be able to send the value of the key pressed. I have managed to send data which I write in code but when I press a key the data does not reach the slave device for some reason.

Here is the code for the master:

/*
 * SPI.c
 *
 * Created: 2/18/2017 10:09:10 AM
 *  Author: Paul
 */

#define F_CPU 8000000

//SPI master
#include <avr/io.h>
#include <stdlib.h>
#include <util/delay.h>
#include <avr/interrupt.h>





void SPIMasterInit(void);
void SPIMasterSend(int key);
int GetKeyPressed();



int main(void)
{
 //SPIMasterInit();
 int key;

 while (1)
 {
  key=GetKeyPressed(); // key gets read properly

  SPIMasterSend(key); // send the read value of the key!!!
 }
}



//SPI init
void SPIMasterInit(void)
{
 //set MOSI, SCK and SS as output
 DDRB |= (1<<PB3)|(1<<PB5)|(1<<PB2);
 //set SS to high
 PORTB |= (1<<PB2);
 //enable master SPI at clock rate Fck/16
 SPCR = (1<<SPE)|(1<<MSTR)|(1<<SPR0);
}

//master send function
void SPIMasterSend(int key)
{
 //select slave( SS must be pulled to ground before sending data )
 PORTB &= ~(1<<PB2);
 //send data(=1)
 SPDR=key; // this is the data sent!!!!
 //wait for transmition complete
 while (!(SPSR &(1<<SPIF)));
 //SS to high
 PORTB |= (1<<PB2);
}

int GetKeyPressed()
{
      int r,c;

      PORTD|= 0X0F;

      for(c=0;c<3;c++)
      {
         DDRD&=~(0X7F);

         DDRD|=(0X40>>c);
         for(r=0;r<4;r++)
         {
            if(!(PIND & (0X08>>r)))
            {
               return (r*3+c);
            }
         }
      }

      return 0XFF;//Indicate No key pressed
}

And here is the code for the slave device:

/*
 * slave.c
 *
 * Created: 2/18/2017 10:48:09 AM
 *  Author: Paul
 */

//SPI slave

#define F_CPU 8000000

#include <avr/io.h>
#include <stdlib.h>
#include <util/delay.h>
#include <avr/interrupt.h>
#include "lcd.h"
#include "myutils.h"



void SPISlaveInit(void);
void InitLCD();

ISR(SPI_STC_vect)
{
 uint8_t recievedData;
 recievedData = SPDR;
 if(recievedData == 0) PORTB |= (1<<0);
}



int main(void)
{
 
 int key;
 DDRB |= (1<<0); // check led set as output

 InitLCD();
 sei();

 while (1)
 {
 
 
 }
}


void SPISlaveInit(void)
{
 //set MISO as output
 DDRB |= (1<<PB4);
 //enable SPI and enable SPI interrupt
 SPCR = (1<<SPE)|(1<<SPIE);
}


void InitLCD()
{
    LCDInit(LS_NONE|LS_NONE);
    LCDClear();
    LCDWriteString("Test text ");
    _delay_ms(150);
    LCDClear();
}

Here is how I connected everything. Based on my code whenever I press keypad(1) the LED should light up. However the LED is off at all times.

Please help me correct this. Thank you.

 

[Cantafford]

I forgot to actually call the init functions for both slave and master...it works now.