Hacking STEM Electromagnetic Sensor

// ----------------------------------------------------------------------------
// Electromagnetic Sensor Code for use with the Sensor Library 
// available from Microsoft Education Workshop at http://aka.ms/data-streamer
// 
// This project uses an Arduino UNO microcontroller board. More information can
// be found by visiting the Arduino website: 
// https://www.arduino.cc/en/main/arduinoBoardUno 
//  
// This code reads in the analog voltage for an electromagnetic sensor connected
// to Arduino pin A0, then prints the data to Serial Monitor which can be read
// and analyzed in Microsoft Excel via the Data Streamer add-in.
// 
// Comments, contributions, suggestions, bug reports, and feature requests 
// are welcome! For source code and bug reports see: 
// http://github.com/[TODO github path to Hacking STEM] 
// 
// Copyright 2019, Microsoft EDU Workshop - HackingSTEM 
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights to
// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
// of the Software, and to permit persons to whom the Software is furnished to do
// so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 
// SOFTWARE. 
// ----------------------------------------------------------------------------

// Program variables ----------------------------------------------------------
int exampleVariable = 0;
int sensorPin = A0;

// Serial data variables ------------------------------------------------------
const byte kNumberOfChannelsFromExcel = 6; //Incoming Serial Data Array
// IMPORTANT: This must be equal to number of channels set in Data Streamer

const char kDelimiter = ',';    // Data Streamer expects a comma delimeter
const int kSerialInterval = 50;   // Interval between serial writes
unsigned long serialPreviousTime; // Timestamp to track serial interval

char* arr[kNumberOfChannelsFromExcel];

// SETUP ----------------------------------------------------------------------
void setup() {
  // Initializations occur here
  Serial.begin(9600);  
}

// START OF MAIN LOOP --------------------------------------------------------- 
void loop()
{
  // Process sensors
  processSensors();

  // Read Excel variables from serial port (Data Streamer)
  processIncomingSerial();

  // Process and send data to Excel via serial port (Data Streamer)
  processOutgoingSerial();

//   if ( strcmp ("Apple", arr[0]) == 0){ // Compares STR1 to STR2 returns 0 if true.
//       Serial.println("working");
//   }
}

// SENSOR INPUT CODE-----------------------------------------------------------
void processSensors() 
{
  // Add sensor processing code here
  exampleVariable = analogRead( sensorPin );
}

// Add any specialized methods and processing code here

// OUTGOING SERIAL DATA PROCESSING CODE----------------------------------------
void sendDataToSerial()
{
  // Send data out separated by a comma (kDelimiter)
  // Repeat next 2 lines of code for each variable sent:

  Serial.print(exampleVariable);
  Serial.print(kDelimiter);
  
  Serial.println(); // Add final line ending character only once
}

//-----------------------------------------------------------------------------
// DO NOT EDIT ANYTHING BELOW THIS LINE
//-----------------------------------------------------------------------------

// OUTGOING SERIAL DATA PROCESSING CODE----------------------------------------
void processOutgoingSerial()
{
   // Enter into this only when serial interval has elapsed
  if((millis() - serialPreviousTime) > kSerialInterval) 
  {
    serialPreviousTime = millis(); // Reset serial interval timestamp
    sendDataToSerial(); 
  }
}

// INCOMING SERIAL DATA PROCESSING CODE----------------------------------------
void processIncomingSerial()
{
  if(Serial.available()){
    parseData(GetSerialData());
  }
}

// Gathers bytes from serial port to build inputString
char* GetSerialData()
{
  static char inputString[64]; // Create a char array to store incoming data
  memset(inputString, 0, sizeof(inputString)); // Clear the memory from a pervious reading
  while (Serial.available()){
    Serial.readBytesUntil('\n', inputString, 64); //Read every byte in Serial buffer until line end or 64 bytes
  }
  return inputString;
}

// Seperate the data at each delimeter
void parseData(char data[])
{
    char *token = strtok(data, ","); // Find the first delimeter and return the token before it
    int index = 0; // Index to track storage in the array
    while (token != NULL){ // Char* strings terminate w/ a Null character. We'll keep running the command until we hit it
      arr[index] = token; // Assign the token to an array
      token = strtok(NULL, ","); // Conintue to the next delimeter
      index++; // incremenet index to store next value
    }
}