Duplicate an array of Strings over Serial

Using Arduino Programming Questions
1

Hi all,
I have been trying to send an array of values over serial, essentially duplicating it into another Arduino, with no success. I can successfully print the entire array to the receiving end by using a for loop, but that was about all I was able to do, as if I were to try and Serial.read() this into the index of an array[0], the entire array from the sending end would be placed in index zero, which is not what I want. Is there any way to do this?
Thanks

2

Thread moved as requested.

3

We can't see your code.

4

The serial input basics tutorial may be of interest. It reads serial data into a null terminated character array (string).

It is a good idea to stay away from using the String class in the small memory Arduinos. Here is why.

5

adamboro237:
Hi all,
I have been trying to send an array of values over serial, essentially duplicating it into another Arduino, with no success. I can successfully print the entire array to the receiving end by using a for loop, but that was about all I was able to do, as if I were to try and Serial.read() this into the index of an array[0], the entire array from the sending end would be placed in index zero, which is not what I want. Is there any way to do this?
Thanks

Yes. Post the code you have tried and we will help you figure out what is wrong.

6

Thanks for the quick replies - here is my code for both the sender and receiver.
Sender:

// sender code

int count = 0;

String array[] = {"dog","cat","snake"};

void setup(){
	Serial.begin(9600);
}

void loop(){
  
	while(count < 1){
		for(int i = 0; i < sizeof(array)/sizeof(array[0]); i ++){
			Serial.print(array[i]);
          	Serial.print(',');
		}
      count ++;
	}
}

Receiver:

// receiving end

// initialize empty array
// iterate through each received element
// if comma, move to next array index, and write value
// if other value, write current value to current array index

// cant figure out how to add multiple characters to same array?
// for some reason nothing in array at the end

int ind = 0;

String array[] = {};

String fragments;

void setup(){
  Serial.begin(9600);
}

void loop(){
  if(Serial.available() > 0){
    fragments = Serial.readString();
    //Serial.println(fragments);
  }
  for(int i = 0; i < fragments.length(); i ++){
    if(fragments.charAt(i) == ','){
      ind ++;
    }
    else {
      array[ind] = fragments.charAt(i);
    }
  }
  for(int x = 0; x < sizeof(array); x ++){ // check contents of duplicated array
    Serial.println(array[x]);
  }
}

For some reason, the duplicated array has nothing in it, and even if it did work, I assume that only one value would be added to each index, whereas to duplicate the array, some array indexes would need a string of multiple characters, not just one.
Ideally, I would like to have the same String array as in the sender, in the receiver.
Thanks

7

I am not opposed to using a different data type such as char or even integers, however, I have had a similar issue with all of these.

8

Your String array is of zero size. Individual Strings can grow dynamically, arrays, not so much.

9

You can easily send arrays via UART between Arduinos automatically using SerialTransfer.h. It comes with many examples and is installable via the Arduino IDE's Libraries Manager