Hello! I am trying to write a script to print the time and date from an RTC and data from an analog pin to an SD card and I am having some trouble. Everything is wired correctly, I can read and write to the SD card and the RTC is giving me the correct time and date. The script I am posting was created by my colleague to read change on the A0 pin and I am trying to add the RTC and SD card scripts I was using to this existing script. Everything compiles fine but I am unable to write any data to the SD card and the serial monitor only prints 'initializing SD card'. What am I doing wrong here? I am a huge Arduino noob (bought my Uno two weeks ago now!) and I don't know the code very well. Any help you guys could provide would be most welcome; thanks Arduino Community!!
/*
Gurly Flow meter logger
Rockhound86 and Dr. M-H
*/
#include <Wire.h>
#include "RTClib.h"
#include <SPI.h>
#include <SD.h>
RTC_PCF8523 rtc;
char daysOfTheWeek[7][12] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};
const float thresh = 10.0; //value bellow which voltage is low due to switch closure 10~=0.05v
const float stradThresh = -1.0; //measures how far sucessive readings are above and below thresh
unsigned long lastDebounceTime = 0; // the last time voltage change was detected
unsigned long debounceDelay = 20; // the debounce time; increase if the output flickers
unsigned long initClosure = 0; // initial closure time
unsigned long prevClosure = 0; // second closure time
unsigned long closureInterval = 9999999; //time interval between switch closures, initiallize to 2:46:40hrs
float revpersec = 0.0; //switch closures per second
float rpm = 0.0; //switch closures per min
int lastReading = 1000;
int switchState = 1000;
int crossingFlag = 0;
File datafile;
void setup()
{
Serial.begin(57600);
Serial.print("Initializing SD card...");
if (!SD.begin(4)) {
Serial.println("initialization failed!");
while (1);
}
Serial.println("initialization done.");
}
void loop() {
int reading = analogRead(A0);
if ((reading-thresh)*(lastReading-thresh) < stradThresh) {
lastDebounceTime = millis(); // Reset the debouncing timer
//Serial.println(77); //check lastDebounceTime set
}
if ((millis() - lastDebounceTime) > debounceDelay) {
// If the reading has been below (or above) thresh longer than
// debounceDelay, the voltage is not bouncing across thresh
if ((reading-thresh)*(switchState-thresh) < stradThresh) {
switchState = reading;
Serial.println(888); //indicate threshold crossing
datafile.print(888); //print to SD card
if (switchState < thresh) { //if stable reading is below thresh the the switch is closed
initClosure=millis();
closureInterval = initClosure-prevClosure;
Serial.print(closureInterval);
datafile.print(closureInterval);
prevClosure=initClosure;
Serial.write(' ');
//rpm=60000.0/closureInterval;
//Serial.print(rpm);
Serial.write(' ');
datafile.print(' ');
Serial.println(reading);
datafile.print(reading);
}
else {
Serial.println(9999); //indicate switch opening
datafile.print(9999);
}
}
}
datafile = SD.open("datafile.txt", FILE_WRITE);
DateTime now = rtc.now();
if (! rtc.begin())
Serial.println("Couldn't find RTC");
while (1);
if (! rtc.initialized()) {
Serial.println("RTC is NOT running!");
// following line sets the RTC to the date & time this sketch was compiled
rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
// This line sets the RTC with an explicit date & time, for example to set
// January 21, 2014 at 3am you would call:
// rtc.adjust(DateTime(2014, 1, 21, 3, 0, 0));
}
lastReading = reading;
datafile.close();
}
but you then don't use that value for anything, including not writing the date and time to the file.