[chronojump] Moved ForceSensor.ino

[Xavier Padullés <xpadulles src gnome org>]

commit 04ba6af67aa04e371fcbca5dfc0b91a1ee159b0d
Author: Xavier Padullés <x padulles gmail com>
Date:   Thu Aug 10 15:12:08 2017 +0200

    Moved ForceSensor.ino

 arduino/ForceSensor/ForceSensor.ino |  196 +++++++++++++++++++++++++++++++++++
 1 files changed, 196 insertions(+), 0 deletions(-)
---
diff --git a/arduino/ForceSensor/ForceSensor.ino b/arduino/ForceSensor/ForceSensor.ino
new file mode 100644
index 0000000..460660e
--- /dev/null
+++ b/arduino/ForceSensor/ForceSensor.ino
@@ -0,0 +1,196 @@
+/*
+  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 is the calibration sketch. Use it to determine the calibration_factor that the main example uses. It 
also
+  outputs the zero_factor useful for projects that have a permanent mass on the scale in between power 
cycles.
+
+  Setup your scale and start the sketch WITHOUT a weight on the scale
+  Once readings are displayed place the weight on the scale
+  Press +/- or a/z to adjust the calibration_factor until the output readings match the known weight
+  Use this calibration_factor on the example sketch
+
+  This example assumes pounds (lbs). If you prefer kilograms, change the Serial.print(" lbs"); line to kg. 
The
+  calibration factor will be significantly different but it will be linearly related to lbs (1 lbs = 
0.453592 kg).
+
+  Your calibration factor may be very positive or very negative. It all depends on the setup of your scale 
system
+  and the direction the sensors deflect from zero state
+  This example code uses bogde's excellent library: https://github.com/bogde/HX711
+  bogde's library is released under a GNU GENERAL PUBLIC LICENSE
+  Arduino pin
+  2 -> HX711 CLK
+  3 -> DOUT
+  5V -> VCC
+  GND -> GND
+
+  Most any pin on the Arduino Uno will be compatible with DOUT/CLK.
+
+  The HX711 board can be powered from 2.7V to 5V so the Arduino 5V power should be fine.
+
+*/
+
+#include "HX711.h"
+
+#define DOUT  3
+#define CLK  2
+
+//Version number
+String version = "Force_Sensor-0.1";
+
+HX711 scale(DOUT, CLK);
+
+//Data comming from the cell after resting the offset weight
+float offsetted_data = 0;
+
+//Data resulting of appying the calibration_factor to the offsetted_data
+float scaled_data = 0;
+
+//The weight used to calibrate the cell
+float weight = 0.0;
+
+//Wether the sensor has to capture or not
+boolean capturing = false;
+
+unsigned long lastTime = 0;
+unsigned long currentTime = 0;
+
+void setup() {
+  Serial.begin(115200);
+
+  
+  //The factor to convert the units coming from the cell to the units used in the calibration
+  scale.set_scale(915.0); // Usual value  in Chronojump strength gauge
+
+}
+
+void loop() {
+
+  unsigned long elapsedTime = 0;
+  if (capturing)
+  {
+    currentTime = micros();
+
+    //Managing the timer overflow
+    if (currentTime > lastTime)      //No overflow
+    {
+      elapsedTime = currentTime - lastTime;
+    } else  if (currentTime <= lastTime)  //Overflow
+    {
+      elapsedTime = (4294967295 - lastTime) + currentTime; //Time from the last measure to the overflow 
event plus the currentTime
+    }
+
+    Serial.print(elapsedTime);
+    Serial.print(";");
+    Serial.println(scale.get_units(), 1); //scale.get_units() returns a float
+  }
+
+}
+
+void serialEvent()
+{
+  String inputString = Serial.readString();
+  String commandString = inputString.substring(0, inputString.lastIndexOf(":"));
+//  while (Serial.available())
+//  {
+//    char inChar = (char)Serial.read();
+//    inputString += inChar;
+//    if (inChar == '\n') {
+//       commandString = inputString.substring(0, inputString.lastIndexOf(":"));
+//    }
+
+      if (commandString == "start_capture") {
+        start_capture();
+      } else if (commandString == "end_capture"){
+        end_capture();
+      } else if (commandString == "get_version"){
+        get_version();
+      } else if (commandString == "get_calibration_factor"){
+        get_calibration_factor();
+      } else if (commandString == "set_calibration_factor"){
+        set_calibration_factor(inputString);
+      } else if (commandString == "calibrate"){
+        calibrate(inputString);
+      } else if (commandString == "get_tare"){
+        get_tare();
+      } else if (commandString == "set_tare"){
+        set_tare(inputString);
+      } else if (commandString == "tare"){
+        tare();
+      } else {
+        Serial.println("Not a valid command");
+      }
+      inputString = "";
+//  }
+}
+
+void start_capture()
+{
+  Serial.println("Starting capture...");
+  capturing = true;
+}
+
+void end_capture()
+{
+  capturing = false;
+  Serial.println("Capture ended");
+}
+void get_version()
+{
+  Serial.println(version);
+}
+
+void get_calibration_factor()
+{
+  Serial.println(scale.get_scale());
+}
+
+void set_calibration_factor(String inputString)
+{
+  //Reading the argument of the command. Located within the ":" and the ";"
+  String calibration_factor = get_command_argument(inputString);
+  //Serial.println(calibration_factor.toFloat());
+  scale.set_scale(calibration_factor.toFloat());
+  Serial.println("Calibration factor set");
+}
+
+void calibrate(String inputString)
+{
+  //Reading the argument of the command. Located within the ":" and the ";"
+  String weightString = get_command_argument(inputString);
+  float weight = weightString.toFloat();
+  //mean of 255 values comming from the cell after resting the offset.
+  double offsetted_data = scale.get_value(255);
+
+  //offsetted_data / calibration_factor
+  float calibration_factor = offsetted_data / weight / 9.81; //We want to return Newtons.
+  scale.set_scale(calibration_factor);
+  Serial.println("Calibrating OK");
+}
+
+void tare()
+{
+  scale.tare(255); //Reset the scale to 0 using the mean of 255 raw values
+  Serial.println("Taring OK");
+}
+
+void get_tare()
+{
+  Serial.println(scale.get_offset());
+}
+
+void set_tare(String inputString)
+{
+  String tare = get_command_argument(inputString);
+  long value = tare.toInt();
+  scale.set_offset(value);
+  Serial.println("Tare set");
+}
+
+String get_command_argument(String inputString)
+{
+  return(inputString.substring(inputString.lastIndexOf(":") + 1, inputString.lastIndexOf(";")));
+}
+