SD card data acquisition

Projects General Guidance
8

I require the data to be logged with a starting time of 00:00:00 when power is applied to pin 3.

I have added some variables and code to record the first time when pin 3 goes HIGH. Then, the timeZeroMillis value is later subtracted from runMillis.

#include <SD.h>

File file;

boolean recordTimeZero = true;
unsigned long timeZeroMillis;

void setup()
{

  // Sets analog pins to input
  pinMode(A0, INPUT);
  pinMode(A1, INPUT);
  pinMode(A2, INPUT);
  pinMode(A3, INPUT);

  // Sets analog pins to input
  pinMode(3, INPUT);
  pinMode(2, OUTPUT);


  // Opens the serial connection
  Serial.begin(500000);
  SD.begin(10);
  file = SD.open("WR_TEST5.TXT", O_CREAT | O_WRITE);

}

void loop()

{
  unsigned long startTime = 0;
  unsigned long intreval = 2000UL; // 120 seconds
  unsigned long previousInterval = 0;
  unsigned long intreval1 = 5000UL; // 60 seconds
  unsigned long previousInterval1 = 0;

  delayMicroseconds(10);

  while  (digitalRead(3) == HIGH)
  {
    delayMicroseconds(100);
    startTime = millis();
    if (recordTimeZero)
    {
      recordTimeZero = false;
      timeZeroMillis = startTime;
    }

    for (; millis() < startTime + 2000UL;)
    {
      char tuf[10];
      digitalWrite(2, LOW);
      sprintf(tuf, "low ");
      //Serial.print(tuf);
      file.print(tuf);
      dataLog();

      if (digitalRead(3) == LOW)
      {
        break;
      }

    }

    for (; millis() < startTime + 7000UL;)
    {
      char tuf1[10];
      digitalWrite(2, HIGH);
      sprintf(tuf1, "high ");
      //Serial.print(tuf1);
      file.print(tuf1);

      dataLog();


      if (digitalRead(3) == LOW)
      {
        break;
      }
    } file.flush();
  }
}

void dataLog()
{
  char buf[100];
  char buf1[50];

  //Pressure transducers
  int PT1A;
  int PTT1;
  int PT1B;
  int PT1C;

  unsigned long runMillis = millis() - timeZeroMillis;
  //unsigned long allSeconds = (millis() / 1000;
  unsigned long allSeconds = runMillis / 1000;
  int runHours = allSeconds / 3600;
  int secsRemaining = allSeconds % 3600;
  int runMinutes = secsRemaining / 60;
  int runSeconds = secsRemaining % 60;

  // Sets values of incoming analog pin data to transducer nnumbers
  PT1A = analogRead(A0); // Reads data from analog pin A0
  PTT1 = analogRead(A1); // Reads data from analog pin A1
  PT1B = analogRead(A2); // Reads data from analog pin A2
  PT1C = analogRead(A3); // Reads data from analog pin A3

  sprintf(buf, "Runtime%02d:%02d:%02d ", runHours, runMinutes,
          runSeconds);
  sprintf(buf1, "PT1A: %d; PTT1: %d; PT1B: %d; PT1C: %d", PT1A, PTT1, PT1B, PT1C);
  /*Serial.print(buf);
    Serial.println(buf1);*/

  file.print(buf);
  file.println(buf1);

}

EDIT: I'm not clear on what is controlling pin 3 and if there are indeed breaks and resumptions of the data recording. If you want to reset the time after a break, then set recordTimeZero back to true when pin 3 goes low and the break occurs.