Activity-Monitoring.ino

#include <SPI.h>

#include <TinyGPS++.h>

#include "SD.h"

/************************************************************
           Variables and objects declaration
************************************************************/

#define FILENAME "GPS_data.txt"

/************************ Pins ********************************/
constexpr unsigned int RX_PIN = 8;
constexpr unsigned int TX_PIN = 9;
constexpr unsigned int CS_SD = 10;
constexpr unsigned int EMG = A0;
constexpr unsigned int ECG = A1;
constexpr unsigned int TEMPERATURE_PIN = A2;

/****************** GPS parameters ***************************/
float latitude, longitude, altitude;
unsigned long gpsLoggingInterval = 5000; //ms
String day, month, year, hour, minute, 
second,speed, sats, course, hdop;

/****************** Reads Params ****************************/
int bufferArraySize = 10; //units
int delayPeriod = 3; //ms
unsigned long previousTime = 0; //ms
unsigned long currentTime = 0; //ms

/******************** Objects *******************************/
File myFile;
TinyGPSPlus gps;

/************************************************************
                      Setup functions
************************************************************/
int init_SD() {
  if (!SD.begin(CS_SD)) {
    Serial.println("Could not begin SD");
    return 0;
  } else {
    myFile = SD.open(FILENAME, FILE_WRITE);
    if (myFile) {
      myFile.println("EMG, ECG, T, Lat, Long, Alt[m], Speed[km/k], Course, Sats, hdop, Date, Time\r");
      myFile.close();
      return 1;
    } else {
      Serial.println("Error opening GPS_data.txt");
      return 0;
    }
  }
}

void setup() {
  Serial.begin(9600);
  while (!Serial) delay(10000);
  while (true) {
    if (millis() > 5000 && gps.charsProcessed() < 10) {
      Serial.println("GPS not detected, waiting 10 sec...");
      delay(10000);
    } else {
      break;
    }
  }

  while (true) {
    Serial.println("Initializing SD card...");
    if (init_SD() == 0) {
      Serial.println("Initialization failed!");
      delay(10000);
    } else {
      Serial.println("Initialization done, file has been created");
      break;

    }
  }
}

/************************************************************
                     Obtain GPS data
************************************************************/
void refresh_date_and_time() {
  if (gps.date.isValid()) {
    month = gps.date.month();
    day = gps.date.day();
    year = gps.date.year();
  }
  if (gps.time.isValid()) {
    if (gps.time.hour() < 10)
    ;
    hour = gps.time.hour();
    if (gps.time.minute() < 10)
    ;
    minute = gps.time.minute();
    if (gps.time.second() < 10)
    ;
    second = gps.time.second();
  }
}

void log_full_data() {
  myFile = SD.open(FILENAME, FILE_WRITE);
  String body_data = String(analogRead(EMG)) + ',' + String(analogRead(ECG)) + ',';
  if (myFile) {
    myFile.print("\r\n");
    myFile.print(body_data);
    refresh_date_and_time();
    String temp_and_gps_data = String(analogRead(TEMPERATURE_PIN)) + ',' + String(gps.location.lat(), 6) +
      ',' + String(gps.location.lng(), 6) + ',' + String(gps.altitude.meters()) + ',' + String(gps.speed.kmph()) + ',' + String(gps.course.deg()) +
      ',' + String(gps.satellites.value()) + ',' + String(gps.hdop.value()) + ',' + String(year) + '-' + String(month) + '-' + String(day) +
      ',' + String(hour) + ':' + String(minute) + ':' + String(second);
    myFile.print(temp_and_gps_data);
    Serial.println(temp_and_gps_data);
  }
  myFile.close();
}

void log_body_data() {
    int emg_arr[bufferArraySize];
    int ecg_arr[bufferArraySize];
    for (unsigned int i = 0; i < bufferArraySize; i++) {
        emg_arr[i] = analogRead(EMG);
        ecg_arr[i] = analogRead(ECG);
        delay(delayPeriod);
    }
    myFile = SD.open(FILENAME, FILE_WRITE);
    if (myFile) {
        for (unsigned int i = 0; i < bufferArraySize; i++) {
            myFile.print("\n");
            myFile.print(ecg_arr[i]);
            myFile.print(',');
            myFile.print(emg_arr[i]);
        }
    }
    myFile.close();
}

void wait_till_serial_available() {
  while (!Serial.available()) {
  }
  gps.encode(Serial.read());
  log_full_data();
}

/************************************************************
                           Loop
************************************************************/

void loop() 
{
  currentTime = millis();

  if (currentTime - previousTime >= gpsLoggingInterval) 
  {
    if ((Serial.available()) > 0) 
    {
      if ((gps.encode(Serial.read()))) 
      {
        log_full_data();
        previousTime = millis();
      }
    }
    else 
    {
      wait_till_serial_available();
      previousTime = millis();
    }
  }
  else
  {
    log_body_data();
  }
}