#include <SoftwareSerial.h>

const int buttonPin = PA7; 
const int redLedPin = PA3;
const int greenLedPin = PB2;
int buttonState = 0; 

SoftwareSerial Serial(PA0, PA1); // RX, TX


void setup() {
  Serial.begin(9600);
  // setting the LEDs to outputs and the button to output
  pinMode(redLedPin, OUTPUT);
  pinMode(greenLedPin, OUTPUT);
  pinMode(buttonPin, INPUT_PULLUP);


}

void loop() {
   buttonState = digitalRead(buttonPin);

    if (buttonState == LOW) {
      digitalWrite(redLedPin, HIGH);
      Serial.print("The red LED is on");
  } else {
    // turn LED off:
    digitalWrite(redLedPin, LOW);
  }

}