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Ekin Karadağ
Ekin Karadağ
  • 11
  • 3
//MASTER

#include<SPI.h>

String textSend="", textReceive="";

void setup(){
  
  Serial.begin(115200);
  
  SPI.begin();
  SPI.setClockDivider(SPI_CLOCK_DIV8);    //Sets clock for SPI communication at 8 (16/8=2Mhz)
  digitalWrite(SS,LOW);
}

void loop(){
  
  textSend=""; textReceive="";
  textSend = Serial.readString();
  if(textSend != ""){
    for(int i = 0; i < textSend.length(); i++){
      delayMicroseconds (20);
      SPI.transfer(textSend[i]);
    }
    
    Serial.print ("PC1"Master: ");
    Serial.println (textSend);
  }else{
    int i = 0;
    char c;
    do{
      delayMicroseconds (20);
      c = SPI.transfer(1);
      textReceive += c;
      i++;
    }while(textReceive[i] != 0);
    
    if(textReceive[i] == 0){
      Serial.print ("PC2"Slave: ");
      Serial.println (textReceive);
      textReceive = "";
    }
  }
}

//SLAVE

#include<SPI.h>

String textSend="";
String textReceive="";

void setup (void){
  Serial.begin(115200);
  pinMode(MISO, OUTPUT);
  SPCR |= _BV(SPE);
  SPCR |= _BV(SPIE);
  SPI.attachInterrupt();

}

ISR (SPI_STC_vect){ //Interrupt Service Routine
  
  byte c = SPDR;
  
  if(c != 1){ //Slave receives
    for(int i = 0; i < textReceive.length(); i++){
      textReceive += SPDR;
    }
    if(textReceive.length() > 0){
      Serial.print("PC1"Master: ");
      Serial.println(textReceive);
      textReceive = "";
    }
  }else{
    for(int i = 0; i < textSend.length(); i++){
      delayMicroseconds(20);
      SPDR = textSend[i];
    }
    if(textSend != ""){
      Serial.print("PC2"Slave: ");
      Serial.println(textSend);
      textSend = "";
    }
  }
}

void loop() {
  if(textSend == "")
    textSend = Serial.readString();
  

}

//MASTER

#include<SPI.h>

String textSend="", textReceive="";

void setup(){
  
  Serial.begin(115200);
  
  SPI.begin();
  SPI.setClockDivider(SPI_CLOCK_DIV8);    //Sets clock for SPI communication at 8 (16/8=2Mhz)
  digitalWrite(SS,LOW);
}

void loop(){
  
  textSend=""; textReceive="";
  textSend = Serial.readString();
  if(textSend != ""){
    for(int i = 0; i < textSend.length(); i++){
      delayMicroseconds (20);
      SPI.transfer(textSend[i]);
    }
    
    Serial.print ("PC1: ");
    Serial.println (textSend);
  }else{
    int i = 0;
    char c;
    do{
      delayMicroseconds (20);
      c = SPI.transfer(1);
      textReceive += c;
      i++;
    }while(textReceive[i] != 0);
    
    if(textReceive[i] == 0){
      Serial.print ("PC2: ");
      Serial.println (textReceive);
      textReceive = "";
    }
  }
}

//SLAVE

#include<SPI.h>

String textSend="";
String textReceive="";

void setup (void){
  Serial.begin(115200);
  pinMode(MISO, OUTPUT);
  SPCR |= _BV(SPE);
  SPCR |= _BV(SPIE);
  SPI.attachInterrupt();

}

ISR (SPI_STC_vect){ //Interrupt Service Routine
  
  byte c = SPDR;
  
  if(c != 1){ //Slave receives
    for(int i = 0; i < textReceive.length(); i++){
      textReceive += SPDR;
    }
    if(textReceive.length() > 0){
      Serial.print("PC1: ");
      Serial.println(textReceive);
      textReceive = "";
    }
  }else{
    for(int i = 0; i < textSend.length(); i++){
      delayMicroseconds(20);
      SPDR = textSend[i];
    }
    if(textSend != ""){
      Serial.print("PC2: ");
      Serial.println(textSend);
      textSend = "";
    }
  }
}

void loop() {
  if(textSend == "")
    textSend = Serial.readString();
  

}

//MASTER

#include<SPI.h>

String textSend="", textReceive="";

void setup(){
  
  Serial.begin(115200);
  
  SPI.begin();
  SPI.setClockDivider(SPI_CLOCK_DIV8);    //Sets clock for SPI communication at 8 (16/8=2Mhz)
  digitalWrite(SS,LOW);
}

void loop(){
  
  textSend=""; textReceive="";
  textSend = Serial.readString();
  if(textSend != ""){
    for(int i = 0; i < textSend.length(); i++){
      delayMicroseconds (20);
      SPI.transfer(textSend[i]);
    }
    
    Serial.print ("Master: ");
    Serial.println (textSend);
  }else{
    int i = 0;
    char c;
    do{
      delayMicroseconds (20);
      c = SPI.transfer(1);
      textReceive += c;
      i++;
    }while(textReceive[i] != 0);
    
    if(textReceive[i] == 0){
      Serial.print ("Slave: ");
      Serial.println (textReceive);
      textReceive = "";
    }
  }
}

//SLAVE

#include<SPI.h>

String textSend="";
String textReceive="";

void setup (void){
  Serial.begin(115200);
  pinMode(MISO, OUTPUT);
  SPCR |= _BV(SPE);
  SPCR |= _BV(SPIE);
  SPI.attachInterrupt();

}

ISR (SPI_STC_vect){ //Interrupt Service Routine
  
  byte c = SPDR;
  
  if(c != 1){ //Slave receives
    for(int i = 0; i < textReceive.length(); i++){
      textReceive += SPDR;
    }
    if(textReceive.length() > 0){
      Serial.print("Master: ");
      Serial.println(textReceive);
      textReceive = "";
    }
  }else{
    for(int i = 0; i < textSend.length(); i++){
      delayMicroseconds(20);
      SPDR = textSend[i];
    }
    if(textSend != ""){
      Serial.print("Slave: ");
      Serial.println(textSend);
      textSend = "";
    }
  }
}

void loop() {
  if(textSend == "")
    textSend = Serial.readString();
  

}
Added the codes, fixed the output.
Source Link
Ekin Karadağ
Ekin Karadağ
  • 11
  • 3

It is kind of working. It isI am not sure how to explain it, I'll just showing the first character of the master Arduino's and the slave doesn't display any information at all..show it below.

SlaveMaster: hey
MasterSlave: hi

MasterSlave: h
MasterSlave: h
Master: hhey
MasterSlave: hy
MasterSlave: h
MasterSlave: h
.
.
.
Slave: i
Slave: 
Slave: 
.
.

And the slave doesn't display anythingdisplays only itself:

Slave: hi

I have created for loops to transfer every char of the string seperatly and respectively but this is still the case. I couldn't find any sample code online for independent string transfering via SPI. What could I be doing wrongknow I probably have many mistakes but how can I fix them to work just as I intend to?

Arduino1.pin10 --- Arduino2.pin10

Master Code

//MASTER

#include<SPI.h>

String textSend="", textReceive="";

void setup(){
  
  Serial.begin(115200);
  
  SPI.begin();
  SPI.setClockDivider(SPI_CLOCK_DIV8);    //Sets clock for SPI communication at 8 (16/8=2Mhz)
  digitalWrite(SS,LOW);
}

void loop(){
  
  textSend=""; textReceive="";
  textSend = Serial.readString();
  if(textSend != ""){
    for(int i = 0; i < textSend.length(); i++){
      delayMicroseconds (20);
      SPI.transfer(textSend[i]);
    }
    
    Serial.print ("PC1: ");
    Serial.println (textSend);
  }else{
    int i = 0;
    char c;
    do{
      delayMicroseconds (20);
      c = SPI.transfer(1);
      textReceive += c;
      i++;
    }while(textReceive[i] != 0);
    
    if(textReceive[i] == 0){
      Serial.print ("PC2: ");
      Serial.println (textReceive);
      textReceive = "";
    }
  }
}

Slave Code

//SLAVE

#include<SPI.h>

String textSend="";
String textReceive="";

void setup (void){
  Serial.begin(115200);
  pinMode(MISO, OUTPUT);
  SPCR |= _BV(SPE);
  SPCR |= _BV(SPIE);
  SPI.attachInterrupt();

}

ISR (SPI_STC_vect){ //Interrupt Service Routine
  
  byte c = SPDR;
  
  if(c != 1){ //Slave receives
    for(int i = 0; i < textReceive.length(); i++){
      textReceive += SPDR;
    }
    if(textReceive.length() > 0){
      Serial.print("PC1: ");
      Serial.println(textReceive);
      textReceive = "";
    }
  }else{
    for(int i = 0; i < textSend.length(); i++){
      delayMicroseconds(20);
      SPDR = textSend[i];
    }
    if(textSend != ""){
      Serial.print("PC2: ");
      Serial.println(textSend);
      textSend = "";
    }
  }
}

void loop() {
  if(textSend == "")
    textSend = Serial.readString();
  

}

It is kind of working. It is just showing the first character of the master Arduino's and the slave doesn't display any information at all...

Slave: hey
Master: hi

Master: h
Master: h
Master: h
Master: h
Master: h
Master: h
.
.
.

And the slave doesn't display anything

I have created for loops to transfer every char of the string seperatly and respectively but this is still the case. I couldn't find any sample code online for independent string transfering via SPI. What could I be doing wrong?

Arduino1.pin10 --- Arduino2.pin10

It is kind of working. I am not sure how to explain it, I'll just show it below.

Master: hey
Slave: hi

Slave: 
Slave: 
Master: hey
Slave: y
Slave: 
Slave: 
.
.
.
Slave: i
Slave: 
Slave: 
.
.

And the slave displays only itself:

Slave: hi

I have created for loops to transfer every char of the string seperatly and respectively but this is still the case. I couldn't find any sample code online for independent string transfering via SPI. I know I probably have many mistakes but how can I fix them to work just as I intend to?

Arduino1.pin10 --- Arduino2.pin10

Master Code

//MASTER

#include<SPI.h>

String textSend="", textReceive="";

void setup(){
  
  Serial.begin(115200);
  
  SPI.begin();
  SPI.setClockDivider(SPI_CLOCK_DIV8);    //Sets clock for SPI communication at 8 (16/8=2Mhz)
  digitalWrite(SS,LOW);
}

void loop(){
  
  textSend=""; textReceive="";
  textSend = Serial.readString();
  if(textSend != ""){
    for(int i = 0; i < textSend.length(); i++){
      delayMicroseconds (20);
      SPI.transfer(textSend[i]);
    }
    
    Serial.print ("PC1: ");
    Serial.println (textSend);
  }else{
    int i = 0;
    char c;
    do{
      delayMicroseconds (20);
      c = SPI.transfer(1);
      textReceive += c;
      i++;
    }while(textReceive[i] != 0);
    
    if(textReceive[i] == 0){
      Serial.print ("PC2: ");
      Serial.println (textReceive);
      textReceive = "";
    }
  }
}

Slave Code

//SLAVE

#include<SPI.h>

String textSend="";
String textReceive="";

void setup (void){
  Serial.begin(115200);
  pinMode(MISO, OUTPUT);
  SPCR |= _BV(SPE);
  SPCR |= _BV(SPIE);
  SPI.attachInterrupt();

}

ISR (SPI_STC_vect){ //Interrupt Service Routine
  
  byte c = SPDR;
  
  if(c != 1){ //Slave receives
    for(int i = 0; i < textReceive.length(); i++){
      textReceive += SPDR;
    }
    if(textReceive.length() > 0){
      Serial.print("PC1: ");
      Serial.println(textReceive);
      textReceive = "";
    }
  }else{
    for(int i = 0; i < textSend.length(); i++){
      delayMicroseconds(20);
      SPDR = textSend[i];
    }
    if(textSend != ""){
      Serial.print("PC2: ");
      Serial.println(textSend);
      textSend = "";
    }
  }
}

void loop() {
  if(textSend == "")
    textSend = Serial.readString();
  

}
Source Link
Ekin Karadağ
Ekin Karadağ
  • 11
  • 3

Send Strings via SPI both ways using two Arduino UNOs(Master to Slave & Slave to Master)

I need to create a two way String exchanger via SPI with two Arduino UNOs. Strings and their lengths are independent variables of the main loop and they can change with every iteration. I need both of the Arduinos to communicate with each other regardless of what the strings contain. I want to see basically the same screen with the serial monitor.

It is kind of working. It is just showing the first character of the master Arduino's and the slave doesn't display any information at all...

Basically the main idea for both of the Arduino's is like this:

Slave: hey
Master: hi

Instead I get this on the master:

Master: h
Master: h
Master: h
Master: h
Master: h
Master: h
.
.
.

And the slave doesn't display anything

I have created for loops to transfer every char of the string seperatly and respectively but this is still the case. I couldn't find any sample code online for independent string transfering via SPI. What could I be doing wrong?

Connections:

Arduino1.pin13 --- Arduino2.pin13

Arduino1.pin12 --- Arduino2.pin12

Arduino1.pin11 --- Arduino2.pin11

Arduino1.pin10 --- Arduino2.pin10