Arduino Micro Println prints 0

Question

I am having troubles with my arduino micro. In my programming, I am using the serial. When I use println, nothing shows up in the serial monitor except for 0. So if I type 1, I get back 0 instead of 1, same goes for 3241234 or any random number. Here is the code:

void setup() {
  Serial.begin(9600); //Connect to the serial monitor console
}

void loop() {
    while (Serial.available() == 0); //Wait until Serial is available

    //Read val
    int val = Serial.read() - '0'; //Val that represents input
    delay(500);
    Serial.println(val);
}

So I have another problem and people have asked for the code. Basically, printing a string returns 0.

 void setup() {
  Serial.begin(9600); //Connect to the serial monitor console
}

void loop() {
    while (Serial.available() == 0); //Wait until Serial is available

    //Read val
    int val = Serial.read(); //Val that represents input

    delay(1000);
    if (val == 1) {
      Serial.print('Firing the motor');
    } else {
      Serial.print('Please press 1 to fire the motor.');
    }

    delay(4000);
}

Instead of printing Please press 1 to fire the motor, I get 0 in the console.

Thanks for the help!

Answer 1

Try without

- '0'

You read your data and save into in int. then print that int, when you pass only the int, you get the int as an ASCII-encoded decimal. Why r u doing

- '0'

?

Answer 2

This time you are comparing an integer 1 with a character '1'.

int val = Serial.read(); 

Is reading you pressing the one key and storing it in an integer variable as the number 49 (ASCII '1')

if (val == 1) {

You are now seeing it 49 is the same as 1, which it isn't.

To make your code easier stick to characters.
Change the Serial.Read line to:

const char val = Serial.read(); // Val that represents input 
                                // (const because it will not change).

and the if line to:

if (val == '1')  // '1' character 1 

By making val const you stop yourself accidentally changing it so if you do

if (val = '4') // Compilation error.

Hope that helps.

Answer 3

To your second question, strings in C are surrounded by the double-quote character: ", not the the single-quote or apostrophe character.