// Hall Effect Sensor test, for the STM32 Blue Pill
// Use with A3144, 3144E, OH3144E on eBay

#define HES PC14 // Pin for the Hall Effect sensor
#define LED PC13 // Pin for green LED on STM32

void led_on() {
  digitalWrite(LED, LOW);
}

void led_off() {
  digitalWrite(LED, HIGH);
}

void setup() {
  Serial.begin(9600);
  pinMode(HES, INPUT_PULLUP);   // Pullup must be used for Hall Effect sensor on STM32
  pinMode(LED, OUTPUT);

  led_off();
}

void loop() {
  delay(200);

  // Magnet causes the sensor to go low
  if (digitalRead(HES) == LOW ) {
    led_on();
    Serial.println("Magnet Detected");
  }
  else {
    led_off();
    Serial.println("No Magnet");
  }
}