Arduino to Arduino serial communications help

Projects Interfacing w/ Software on the Computer
21

Your code is not written well to handle serial communication, and contains some things that just look wrong. The point of post #3 was to show you how you can communicate via serial, but you seemed to have missed the point of that.

Can I take a step back and ask what you are trying to achieve?

I'm assuming if you press the button connected to the master, then LED should turn on connected to the slave?

Ultimately you will have 2 buttons and a potentiometer, that will control 3 LEDs (1 via PWM) ?

Is that it?

22

Yes, and I have not missed the point of the post im gonna change my code using that example as reference tommorow. And just to rehash the root of the problem: the arduinos never even try communicating (no RX/TX led flashing) but they work just fine when sending serial data directly inside via monitor.

23

I think you need to think a bit more about what you are trying to do.

If the master simply tells the slave to do something then why do you need to send anything from the slave? Your communication protocol looks way more complicated than it needs to.

24

With all due respect, at 9600 baud, a single character transmission results in a few pulses of light at 100 uS length. Higher baud rates, even less so. Hardly enough to be visible, likely not even. With Serial monitor, typical transmissions are many characters long, so you have better chance of seeing a flash. You continue to demonstrate a very poor understanding of what you're playing with.
Further, your slave still wakes up and talks without permission. Stop, sit down, and write a concise explanation of what you believe is happening in each device, because we have no way of knowing where the gap is between what should be done, and what you are doing.

25

You can take a look at this examples Serial UART Communication between Two Arduino Boards and
Connecting Two Nano Every Boards Through UART

26

Thank you, this along with the others telling me of incompetence has got the code to almost work, and now I only have one issue. How do you take char data and turn it into int data so I can simply write the value to a device to turn it on and off? I want to know this because I plan on using this to control servos and such.

27

If myChar = '1' - '9' then...

int myInt = myChar - '\0';

Or if you have multiple characters in a 0x00 terminated char array (myChar[]), then...

int myInt = atoi(myChar);
28

thanks, ill implement and post complete code when I got time later tonight.

29

It works!, a little buggy but imma fix that and post the code. (also I used serial.write to bypass need for char array)

30

BAREBONES CODE

TRANSMITTER:

//Transmitter (Tx) Arduino Board Code

const int POT=0;
int dataused = 0;
void setup()
{
  Serial.begin(9600);
  
}
void loop()
{
  
  dataused = map(analogRead(A0), 0, 1024, 0, 255);
  
  Serial.write(dataused);
  delay(2);
  
 
}

RECIEVER:

//Receiver (Rx) Arduino Board Code
int button1 = 0;    // pushbutton
char serialinput = ' ';
byte LED = 3;
int dataused = 0;
 
void setup()
{
   pinMode(LED, OUTPUT);
   Serial.begin(9600);
}
void loop()
{
   if(Serial.available())
   {
      dataused = Serial.read(); // save serial input to char
      
     
        
      analogWrite(LED, dataused);
      Serial.println(dataused);
      if (dataused > -1 or dataused < 256)
      delay(2);
      
      {
        Serial.println('K');
      }
    
   
   }
}

later on I will post a not-so barebones version which will look similar to what I began with here (or at least do the beginning intention)