Respected Sir
Thanks a lot for your kind support. Now I am able to receive data form master but after receiving I want to send some data to master back, how can we do this. I have used SPI.transfer() in the master/data-sending code.
Working code.
Sending data code:
#include <SPI.h>// include the SPI library:
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 mm =0;
void setup() {
pinMode (spidata, OUTPUT);// set the spi_data_pin as an output:
SPI.begin();// initialize SPI:
Serial.begin(9600);
}
void loop() {
digitalWrite(spidata,LOW);
SPI.transfer(0x3b); // send in the address and value via SPI:
digitalWrite(spidata,HIGH);// take the SS pin high to de-select the chip:
delay(1500);
}
Receiving data code:
#include <SPI.h>
#include <stdio.h>
#include <avr/io.h>
#include <stdlib.h>
#define MOSI 11
#define MISO 12
#define SCK 13
#define SS 10
int data = 0;
char buff[8];
void setup()
{
pinMode(MOSI, INPUT);
pinMode(MISO, OUTPUT);
pinMode(SCK,INPUT);
pinMode(SS,INPUT);
Serial.begin(9600);
SPCR = 0x40; // Enable SPI in slave mode
// SPI.begin();
delay(500);
}
void loop()
{
Serial.println("Data Received from Master Board");
data = SPI_SlaveReceive();
Serial.println(data, HEX);
data = 0;
}
unsigned char SPI_SlaveReceive()
{
while(!(SPSR & (1<<SPIF)));
return SPDR;
}
Output from receiving code:
Data Received from Master Board
3B
Data Received from Master Board
3B
Data Received from Master Board
3B
Data Received from Master Board
3B
And now what should I do modification in the code so that I can send some data to master once I receive 0x3B from master.
I am trying like this at receiving(slave) side, it is receiving 0x3B from master but not able to send data to master
#include <SPI.h>
#include <stdio.h>
#include <avr/io.h>
#include <stdlib.h>
#define MOSI 11
#define MISO 12
#define SCK 13
#define SS 10
#define sss 9
int data = 0;
char buff[8];
void setup()
{
pinMode(MOSI, INPUT);
pinMode(MISO, OUTPUT);
pinMode(SCK,INPUT);
pinMode(SS,INPUT);
pinMode(sss, OUTPUT);
Serial.begin(9600);
SPCR = 0x40; // Enable SPI in slave mode
// SPI.begin();
delay(500);
}
void loop()
{
int xx;
Serial.println("Data Received from Master Board");
data = SPI_SlaveReceive();
xx = data;
Serial.println(data, HEX);
data = 0;
delay(20);
if(xx == 59)
{
delay(600);
void master_init();
unsigned char send2();
delay(600);
}
}
unsigned char send2(){
digitalWrite(SS, LOW);
WriteByte(16);
digitalWrite(SS, HIGH);
delay(600);}
unsigned char SPI_SlaveReceive()
{
while(!(SPSR & (1<<SPIF)));
return SPDR;
}
void master_init()
{
pinMode(MOSI, OUTPUT);
pinMode(MISO, INPUT);
pinMode(SCK,OUTPUT);
pinMode(SS,OUTPUT);
pinMode(sss, OUTPUT);
}
void WriteByte(byte value) {
SPDR = value;
while (!(SPSR & (1<<SPIF))) ;
return;
}
And at the master side I am doing like this but it is not able to receive the data
#include <SPI.h>// include the SPI library:
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:
#define sss 9
int mm =0;
unsigned char data1 = 0;
void setup() {
pinMode (spidata, OUTPUT);// set the spi_data_pin as an output:
SPI.begin();// initialize SPI:
Serial.begin(9600);
}
void loop() {
//for(mm=0; mm<23;mm++){
digitalWrite(spidata,LOW);
//Serial.println("I am writting on SPI");
//Serial.println(mm, BIN);
SPI.transfer(0x3b); // send in the address and value via SPI:
// SPI.transfer('IMU');
digitalWrite(spidata,HIGH);// take the SS pin high to de-select the chip:
delay(600);
//digitalWrite(sss,LOW);
unsigned char read1();
delay(600);
//digitalWrite(sss,HIGH);
}
unsigned char read1()
{
void slave_init();
data1 = read_ready();
Serial.println(data1, DEC);
data1 = 0;
delay(60);
}
unsigned char read_ready()
{
while(!(SPSR & (1<<SPIF)));
return SPDR;
}
void slave_init()
{
SPCR = 0x40;
pinMode(11, INPUT);
pinMode(12, OUTPUT);
pinMode(13, INPUT);
pinMode(10, INPUT);
delay(600);
}
Kindly suggest me for the modification.