MayFly Data Logger Code

//Sample sketch for logging light and temp/humidity data to microSD card on EnviroDIY Mayfly v1.0

//This sketch does not put the logger to sleep; it is constantly power, so it's not intended for long-term deployments

#include <Arduino.h>

#include<DHT.h> // This library is for temp & humid sensor

#include <Wire.h> // This library is included with the Arduino IDE, and allows communication with I2C/TWI devices

#include "Sodaq_DS3231.h" // Install this library to interact with the Real Time Clock

#include <SD.h> // This library is for the SD CARD

#include <SPI.h>

#include <OneWire.h>

#include <DallasTemperature.h>

//Data wire is plugged into port 7 on Mayfly

#define ONE_WIRE_BUS 7

#define SD_SS_PIN 12

#define FILE_NAME "Datafile.txt"

#define LOGGERNAME "Mayfly Light/Humidity/Temperature Logger"

#define DATA_HEADER "DateTime_UTC,Loggertime,BatteryV,Humidity_percent,Temp_C,Water_temp,Light"

#define DHTPIN 5 // Specifies the pin connected to the DHT signal.

#define DHTTYPE DHT11 // DHT 11

DHT dht(DHTPIN, DHTTYPE);

OneWire oneWire(ONE_WIRE_BUS);

// Pass the OneWire reference to Dallas Temp

DallasTemperature sensors(&oneWire);

String dataRec = "";

int currentminute;

int currentyear;

int currentmonth;

int currentdate;

int currenthour;

long currentepochtime = 0;

//float boardtemp = 0.0;

float lightpercent = 0;

int batteryPin = A6; // select the input pin for the potentiometer

int batterysenseValue = 0; // variable to store the value coming from the sensor

float batteryvoltage; // the calculated battery voltage in volts

//****************************************************************************************************************************

void setup ()

{

Serial.begin(57600);

Serial.println("Mayfly SHT40-Light Logger");

pinMode(8, OUTPUT);

pinMode(9, OUTPUT);

pinMode(20, OUTPUT);

greenred4flash(); //blink the LEDs to show the board is on

sensors.begin();

Wire.begin();

rtc.begin();

dht.begin(); //start dht sensor

setupLogFile();

Serial.println("---------------EnviroDIY Mayfly: ver 1.1------------ ");

Serial.println("| | ");

Serial.println("|Contact: Douglas Fessler | ");

Serial.println("|Date: April 21, 2022 | ");

Serial.println("|Email: FESSLER.DOUGLAS@GMAIL.COM | ");

Serial.println("| | ");

Serial.println("---------------------------------------------------- ");

getNow();

getDateTime();

}

//****************************************************************************************************************************

void loop ()

{

sensors. requestTemperatures(); //send command to get waterprobe temp

float tempF = sensors.getTempFByIndex(0);

tempF = tempF - .7;

digitalWrite(8, HIGH); // turn on the green LED to let you know a sample is being taken

dataRec = createDataRecord();

int light = analogRead(A4); // read the analog light sensor

lightpercent = light/10.23; // scales light reading as a percentage

// float h = dht.readHumidity();

//float t = dht.readTemperature();

dataRec += ",";

addFloatToString(dataRec, dht.readHumidity(),2,2);

dataRec += ",";

addFloatToString(dataRec, dht.readTemperature(true),2,2);

dataRec += ",";

addFloatToString(dataRec, tempF,2,2);

dataRec += ",";

addFloatToString(dataRec, lightpercent, 2, 1);

dataRec += light;

delay(10);

logData(dataRec);

Serial.print("Data Record: ");

Serial.println(dataRec); // print the data record to the serial monitor

String dataRec = "";

digitalWrite(8, LOW);

delay(1000);

}

//****************************************************************************************************************************

void setupLogFile()

{

//Initialise the SD card

if (!SD.begin(SD_SS_PIN))

{

Serial.println("Error: SD card failed to initialise or is missing.");

for (int r=1; r <= 10; r++) // flash the red LED 10 times to let you know there's no memory card

{

digitalWrite(9, HIGH);

delay(400);

digitalWrite(9, LOW);

delay(200);

}

//Check if the file already exists

bool oldFile = SD.exists(FILE_NAME);

//Open the file in write mode

File logFile = SD.open(FILE_NAME, FILE_WRITE);

//Add header information if the file did not already exist

if (!oldFile)

{

logFile.println(LOGGERNAME);

logFile.println(DATA_HEADER);

}

//Close the file to save it

logFile.close();

}

//****************************************************************************************************************************

void logData(String rec)

{

//Re-open the file

File logFile = SD.open(FILE_NAME, FILE_WRITE);

//Write the CSV data

logFile.println(rec);

//Close the file to save it

logFile.close();

}

//****************************************************************************************************************************

String createDataRecord()

{

//Create a String type data record in csv format

String data = getDateTime();

data += ",";

batterysenseValue = analogRead(batteryPin);

batteryvoltage = (3.3/1023.) * 4.7 * batterysenseValue;

data += currentepochtime;

data += ",";

addFloatToString(data, batteryvoltage, 4, 2);

return data;

}

//****************************************************************************************************************************

static void addFloatToString(String & str, float val, char width, unsigned char precision)

{

char buffer[10];

dtostrf(val, width, precision, buffer);

str += buffer;

}

//****************************************************************************************************************************

String getDateTime()

{

String dateTimeStr;

//Create a DateTime object from the current time

DateTime dt(rtc.makeDateTime(rtc.now().getEpoch()));

currentepochtime = (dt.get()); //Unix time in seconds

currentyear = (dt.year());

currentmonth = (dt.month());

currentdate = (dt.date());

currenthour = (dt.hour());

currentminute = (dt.minute());

//Convert it to a String

dt.addToString(dateTimeStr);

return dateTimeStr;

}

//***************************************************************************************************************************

// shows how long the board has been running counts up by seconds,minutes, hours

uint32_t getNow()

{

currentepochtime = rtc.now().getEpoch();

return currentepochtime;

}

//***************************************************************************************************************************

void greenred4flash() // blink the red/green LEDs rapidly a few times at startup

{

for (int i=1; i <= 4; i++){

digitalWrite(8, HIGH);

digitalWrite(9, LOW);

delay(50);

digitalWrite(8, LOW);

digitalWrite(9, HIGH);

delay(50);

}

digitalWrite(9, LOW);

}