/*
 Example using the SparkFun HX711 breakout board with a scale
 By: Nathan Seidle
 SparkFun Electronics
 Date: November 19th, 2014
 License: This code is public domain but you buy me a beer if you use this and we meet someday (Beerware license).

 This example demonstrates basic scale output. See the calibration sketch to get the calibration_factor for your
 specific load cell setup.

 This example code uses bogde's excellent library: https://github.com/bogde/HX711
 bogde's library is released under a GNU GENERAL PUBLIC LICENSE

 The HX711 does one thing well: read load cells. The breakout board is compatible with any wheat-stone bridge
 based load cell which should allow a user to measure everything from a few grams to tens of tons.
 Arduino pin 2 -> HX711 CLK
 3 -> DAT
 5V -> VCC
 GND -> GND
 The HX711 board can be powered from 2.7V to 5V so the Arduino 5V power should be fine.

Wiring bluetooth: 
  GND of HC-05 to GND Arduino, VCC of HC-05 to VCC Arduino,
  TX HC-05 to Arduino Pin 10 (RX)
  RX HC-05 to TX Arduino (TX)

1x19 steel wire specs:
4mm 1350kg
5mm 2100kg
6mm 3028kg  

1mm of strain = 5% break load (for a 2 meter ruler)
*/

#include "HX711.h"
#include <SoftwareSerial.h>
SoftwareSerial BTserial(10, 11); // RX | TX
#define calibration_factor -7780.0 //This value is obtained using the SparkFun_HX711_Calibration sketch

#define DOUT  3
#define CLK  2

HX711 scale(DOUT, CLK);

void setup() {
  BTserial.begin(9600); 
  Serial.begin(9600);

  scale.set_scale(calibration_factor); //This value is obtained by using the SparkFun_HX711_Calibration sketch
  scale.tare(); //Assuming there is no weight on the scale at start up, reset the scale to 0
}

void loop() {
  //BTserial.print("4");
  //BTserial.print(" mm 1x19 = ");
  BTserial.print(scale.get_units() / 8.46, 1);
  BTserial.print("%");
  BTserial.print(",");
  //BTserial.print("5");
  //BTserial.print(" mm 1x19 = ");
  BTserial.print(scale.get_units() / 16.24, 1);
  BTserial.print("%");
  BTserial.print(",");
  //BTserial.print("6");
  //BTserial.print(" mm 1x19 = ");
  BTserial.print(scale.get_units() / 27.93, 1);
  BTserial.print("%");
  BTserial.print(";");
  Serial.print(scale.get_units(), 1); //scale.get_units() returns a float
  Serial.println();
}