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Josep Giner
Asked: 2022-02-24 09:32:20 +0800 CST 2022-02-24 09:32:20 +0800 CST

How can I get the Arduino to read the data from the Python script?

  • 772

I am making a script in Python in which I change the number of the maximum_persons variable and now I am doing it so that from the arduino it reads what is entered by python

The code I have is

import serial, time

arduino=serial.Serial("/dev/ttyACM0",9600)

enviar=raw_input("Introduce un numero de aforo máximo")

arduino.write(str(enviar).encode())
arduino.write('\n'.encode())

ARDUINO

if (Serial.available()>0){
  int maximo_personas = 15;
  int enviado;

  enviado=Serial.parseInt();

  maximo_personas==enviado;

}
python

1 Answers

  1. Best Answer

    python

    On the Python side the script is simpler:

    import serial

arduino=serial.Serial("/dev/ttyACM0",9600)
enviar=input("Introduce un numero de aforo máximo ")
arduino.write(enviar.encode())

    The function inputgives me a unicode string that includes the ENTER at the end. I just need to apply enconde()before I send it.

    Arduino

    On the Arduino side we are going to use the LED mounted on the board to check the reception of data: we will make it blink n / 2times, where nis the value sent by Python:

    int enviado; //Aqui enviamos el numero completo

void setup()
{
  //Inicializamos la comunicacion por Serial
  Serial.begin(9600);
  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(LED_BUILTIN, HIGH);
  enviado = 0;
}

void loop()
{

  if (Serial.available() >= 1) {
    enviado = Serial.parseInt(); //Leer entero por serial
    Serial.read();  // Descartar ENTER al final del entero
  }
  if (enviado) {
    digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN));
    delay(250);
    enviado--;
  }
}

    The caution in using parseInt()is that it doesn't read the ENTER at the end of the number, so we have to add a Serial.read()to get rid of that character.

    Since enviadoit is a global variable, it retains its value across successive iterations of loop.

    In each iteration the state of the LED is changed only once. This is the standard programming pattern in Arduino: each pass through loopshould be as short as possible, in order to allow time to process other events on the board.

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