#include <HX711.h>

HX711 scale;

uint8_t dataPin = 6;
uint8_t clockPin = 7;

uint8_t redLed = A1;
uint8_t greenLed = A2;
uint8_t buzzer = 11;

int force = 0;

void setup() {
  Serial.begin(115200);

  pinMode(redLed, OUTPUT);
  pinMode(greenLed, OUTPUT);
  pinMode(buzzer, OUTPUT);

  scale.begin(dataPin, clockPin);
  // calibrate();

  // load cell calibration factor
  scale.set_scale(123.456);    // this value is obtained by calibrating the scale with known weights
  // reset the scale to zero = 0
  scale.tare(20);
}

void loop() {
  delay(1000);

  force = scale.get_units();
  Serial.print("Force :");
  Serial.println(force);

  if(force < 25){
    // LED lights up green under 25 pounds
    digitalWrite(greenLed, 1);
    digitalWrite(redLed, 0);
    // when it’s under 25 pounds a buzzer turns on
    digitalWrite(buzzer, 1);
  }

  if(force > 25){
    // LED lights up red over 25 pounds
    digitalWrite(redLed, 1);
    digitalWrite(greenLed, 0);
    // when it’s over 25 pounds a buzzer goes off
    digitalWrite(buzzer, 0);
  }
}

void calibrate(){
  if (scale.is_ready()) {
    scale.set_scale();    
    Serial.println("Tare... remove any weights from the scale.");
    delay(5000);
    scale.tare();
    Serial.println("Tare done...");
    Serial.print("Place a known weight on the scale...");
    delay(5000);
    long reading = scale.get_units(10);
    Serial.print("Reading: ");
    Serial.println(reading);
    Serial.println("\nCalibration factor will be the (Reading)/(known weight)");
  }
}