Arduino UNO - read data from user

The first example just reads text from the user and next print it on the screen (serial port monitor). In the beginning, program just checks if there is something to read. If yes, you can start reading the data. In this case, Serial.readBytes function was used which has two jobs to do - read the text and store it in the char array. There is no conversion to anything. The second parameter of the Serial.readBytes function is the number of chars to read, it should be less or equal to the size of the buffer array.

Important is that the buffer has to be cleared every time before reading the next data. To manage this, you can use a library function memset.

xxxxxxxxxx

void setup() {

  // enable serial comunication

  Serial.begin(9600);

}

​

// buffer array

char buff[20];

​

void loop() {

  // if there is something to read

  if(Serial.available()) {

    // just read it and store in the buffer

    Serial.readBytes(buff, 20);

    // and next print the buffer

    Serial.println(buff);

    // clear the buffer

    memset(buff, 0, sizeof(buff));

  }

  delay(10);

}

In this example, the library Serial.parseInt function was used to convert text from the user to the integer value. This is a very simple way to read numbers without any text operations.

To read floating-point number there is available Serial.parseFloat function.

xxxxxxxxxx

void setup() {

  // enable serial comunication

  Serial.begin(9600);

}

​

void loop() {

  // if there is something to read

  if(Serial.available()) {

    // read and convert to integer

    int a = Serial.parseInt();

    // print readed number

    Serial.println(a);

  }

  delay(10);

}