Using softwareSerial

Projects Programming
1

I can get softwareSerial to send data between two Arduino’s but only one character at a time. Then I use myDate +=rc (where rc is the serial read). I can print rc but not myData. All I get is a black triangle with a ? in it.

2

Welcome to the forums. Take a moment to read this: How to get the best out of this forum - Using Arduino / Installation & Troubleshooting - Arduino Forum

It will help others help you.

We can't see your code if you don't post it.

3

What data type is 'myDate' (or 'myData') ?

It would indeed be helpful to see the code. If you can print rc, then evidently the character is being transmitted and received, but myDate/myData is not being handled correctly in some respect.

When you do post the code, please use the Edit -> Copy for Forum feature in the IDE to copy and then paste it into your post.

4

Sorry, myDate should have been myData I have tried setting myData as String, char, and uint8_t but none work This is the code I am using

// Buffer to store incoming commands from serial port

String inData;

void setup() {

Serial.begin(9600);

softSerial.begin(9600);

Serial.println("Serial conection started, waiting for instructions...");

}

void loop() {

while (Serial.available() > 0){

    char rc = softSerial.read();

    myData += rc;

    if (rc == '\\n'){

        Serial.print("Arduino Received: ");

        Serial.print(myData);

}

}

        myData = ""; // Clear recieved buffer

    }
5

Only need one backslash for newline:

if (rc == '\n'){

Not sure what happened to the formatting?
There should be 3 backticks before and after your code. None in-between.
Looks like your code got fragmented somehow. It would be appreciated if you could adjust your post accordingly.

6

So many problems it is hard to know where to start.

Take the advice in post 3 and format your code properly and show all of it.

Why is the while loop based on Serial.available() when is is never read?

The softSerial.read() will return -1 if there is no data. This is probably where your strange results are coming from.

I assume myData is a String - there is no definition shown. This is a very bad way to get a dynamic character string in small AVR processors like the UNO R3. They have poor heap management and limited memory, which leads to crashes.

7

use Serial.readBytesUntil()

// receiving string thru Serial

void process (
    char *s )
{
    Serial.println (s);
}

void loop ()
{
    if (Serial.available())  {
        char buf [90];
        int  n = Serial.readBytesUntil ('\n', buf, sizeof(buf)-1);
        buf [n] = '\0';                 // terminate with nul

        process (buf);
    }
}

void setup ()
{
    Serial.begin   (9600);
    Serial.println ("ready");
}
8

Please correct your post and add code tags around your code.

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  • click on this pencil ➜ that will let you edit your post.
  • Select the part of the text that corresponds to the code
  • Click on the <code/> icon in the toolbar to indicate that it is code
  • click image Save Edit

(Also make sure to properly indent the code in the IDE before copying and pasting it here. This can be done by pressing ctrlT on a PC or cmdT on a Mac)

———

softSerial is not defined in your code, so zero chance it works
your loop checks Serial not softSerial...

I would suggest to study Serial Input Basics to handle this

9

You check the Serial port and then read from the software serial.

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