Yes I am using the same microcontroller they are using. I wired the devices as they described in the paper and tried to use their code, but the device stopped receiving data after about 30 seconds. I contacts the author and they were very helpful about troubleshooting, but they moved to a new job position and haven't worked much with arduinos since they wrote the paper. I did change the sampling rate to 32 hz, which may have drained the battery, but I changed the GPS fix period to every hour.

 

I tried modifying the code to put it into sleep mode for a couple of hours during the day. The code worked for me but again the device did not last more than 24 hours. Granted I was trying to modify the original code with ChatGPT and other scripts that I found, which probably was not the most effecient way. I am taking a coding class this semester so hopefully I can learn how to do this myself at some point. However, any help at this point would be appreciated.

 

#include <Adafruit_GPS.h>
#include <SPI.h>
#include <SD.h>
#include <Wire.h>
#include <Adafruit_LIS3DH.h>
#include <Adafruit_Sensor.h>
#include <ArduinoLowPower.h>
#include <TimeLib.h>  // Time library for timekeeping

const int chipSelect = 4;

int attempts, good_fixes, bad_fixes;

// hardware serial port
#define GPSSerial Serial1
Adafruit_GPS GPS(&GPSSerial);

#define GPSECHO false

uint32_t gpsTimer = millis();
uint32_t accelTimer = millis();
const uint32_t accelInterval = 31; // Interval for approximately 32 Hz

// LIS3DH setup
#define LIS3DH_CLK 13
#define LIS3DH_MISO 12
#define LIS3DH_MOSI 11
#define LIS3DH_CS 10
Adafruit_LIS3DH lis = Adafruit_LIS3DH();

void setup() {
  // while (! Serial ); // uncomment to wait until Serial is ready
  Serial.begin(115200);
  attempts = 0;
  good_fixes = attempts;
  bad_fixes = attempts;

  // Initialization sub-routines defined at end of sketch
  SDcheck();
  GPSconnect();
  accelSetup();
  setTime(0); // Initialize time library, should be synchronized with GPS time
  delay(100);
}

void loop() {
  // Get the current time
  int currentHour = hour();
  int currentMinute = minute();

  // Check if the current time is between 10 AM and 4 PM CDT, which is 5 hours behind UTC time
  if (currentHour >= 15 && currentHour < 21) {
    // Put the device into deep sleep for 1 minute
    Serial.println("Entering sleep mode");
    LowPower.deepSleep(10000); // Sleep for 1 minute
    return;
  }

  char c = GPS.read();
  if (!GPS.fix) Serial.println("no location! no fix!");
  if (GPSECHO)
    if (c) Serial.print(c);
  if (GPS.newNMEAreceived()) {
    if (!GPS.parse(GPS.lastNMEA()))
      return;
  }

  // GPS logging at time interval (30000 = 30 seconds, 3600000 = 1 hour)
  if (gpsTimer > millis()) gpsTimer = millis();
  if (millis() - gpsTimer > 3600000) {
    gpsTimer = millis(); // reset the timer
    attempts = attempts + 1;
    logGPSData();
  }

  // Accelerometer logging at approximately 32 Hz
  if (millis() - accelTimer > accelInterval) {
    accelTimer = millis();
    logAccelData();
  }
}

void SDcheck(void) {
  if (!SD.begin(chipSelect)) {
    Serial.println("Card failed, or not present");
    // don’t do anything more:
    return;
  }
  Serial.println("card initialized.");
  delay(1000);

  File dataFile = SD.open("GPS.CSV", FILE_WRITE);
  if (dataFile) {
    Serial.println("File open. Logging!");
    delay(1000);
  }
  // If the file is not open, pop up an error
  else {
    Serial.println("No file! Not logging!");
    delay(1000);
    return;
  }
}

void GPSconnect(void) {
  GPS.begin(9600);
  GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCGGA);
  GPS.sendCommand(PMTK_SET_NMEA_UPDATE_1HZ); // 1 Hz update rate
  GPS.sendCommand(PGCMD_ANTENNA);
  delay(1000);
  // Ask for firmware version
  GPSSerial.println(PMTK_Q_RELEASE);
}

void logGPSData() {
  File dataFile = SD.open("GPS.CSV", FILE_WRITE);
  if (dataFile) {
    dataFile.print(GPS.day, DEC); dataFile.print('-');
    dataFile.print(GPS.month, DEC); dataFile.print("-20");
    dataFile.print(GPS.year, DEC);
    dataFile.print(", ");
    // time
    dataFile.print(GPS.hour, DEC); dataFile.print(':');
    dataFile.print(GPS.minute, DEC); dataFile.print(':');
    dataFile.print(GPS.seconds, DEC);
    dataFile.print(", ");
    // location data
    if (GPS.fix) {
      good_fixes = good_fixes + 1;
      dataFile.print("GPS lat/lon");
      dataFile.print(", ");
      dataFile.print(GPS.latitudeDegrees, 4); dataFile.print(GPS.lat);
      dataFile.print(", ");
      dataFile.print(GPS.longitudeDegrees, 4); dataFile.print(GPS.lon);
      dataFile.print(", ");
      dataFile.print("Altitude");
      dataFile.print(", ");
      dataFile.print(GPS.altitude);
      dataFile.print(", ");
      dataFile.print("Speed");
      dataFile.print(", ");
      dataFile.print(GPS.speed);
      dataFile.print(", ");
      dataFile.print("Angle");
      dataFile.print(", ");
      dataFile.print(GPS.angle);
      dataFile.print(", ");
      dataFile.print("Fix");
      dataFile.print(", ");
      dataFile.print((int)GPS.fix);
      dataFile.print(", ");
      dataFile.print("FixQuality");
      dataFile.print(", ");
      dataFile.print((int)GPS.fixquality);
      dataFile.print(", ");
      dataFile.print("Satellites");
      dataFile.print(", ");
      dataFile.println((int)GPS.satellites);
    } else {
      bad_fixes = bad_fixes + 1;
      dataFile.print("na, ");
      dataFile.print("na, ");
      dataFile.print("na, ");
      dataFile.print("na, ");
      dataFile.print("na, ");
      dataFile.print((int)GPS.fix);
      dataFile.print(", ");
      dataFile.print((int)GPS.fixquality);
      dataFile.print(", ");
      dataFile.print((int)GPS.satellites);
      dataFile.println(", ");
    }
    dataFile.close();
  }
}

void accelSetup() {
  if (!lis.begin(0x18)) { // change this to 0x19 for alternative i2c address
    Serial.println("Couldn't start");
    while (1) yield();
  }
  Serial.println("LIS3DH found!");
  Serial.print("Range = "); Serial.print(2 << lis.getRange());
  Serial.println("G");
  lis.setRange(LIS3DH_RANGE_4_G); // Set range to 4G
  lis.setDataRate(LIS3DH_DATARATE_50_HZ); // Set data rate to 50 Hz
}

void logAccelData() {
  File accelFile = SD.open("ACCEL.CSV", FILE_WRITE);
  if (accelFile) {
    lis.read(); // get X Y and Z data at once
    sensors_event_t event;
    lis.getEvent(&event);
    if (GPS.fix) {
      accelFile.print(GPS.day, DEC); accelFile.print('-');
      accelFile.print(GPS.month, DEC); accelFile.print("-20");
      accelFile.print(GPS.year, DEC);
      accelFile.print(", ");
      accelFile.print(GPS.hour, DEC); accelFile.print(':');
      accelFile.print(GPS.minute, DEC); accelFile.print(':');
      accelFile.print(GPS.seconds, DEC);
      accelFile.print(", ");
    } else {
      accelFile.print("No GPS fix");
      accelFile.print(", ");
      accelFile.print("No GPS fix");
      accelFile.print(", ");
    }
    accelFile.print("X"); accelFile.print(", "); accelFile.print(event.acceleration.x); accelFile.print(", ");
    accelFile.print("Y"); accelFile.print(", "); accelFile.print(event.acceleration.y); accelFile.print(", ");
    accelFile.print("Z"); accelFile.print(", "); accelFile.print(event.acceleration.z); accelFile.println();
    accelFile.close();
  }
}

Checking the presented code, I realize that you open "GPS.csv" during the check of the SD, but you never close it.

During operation, you open/write/close the file for every sampling. There may be some conflict that could result in a crash.

I would also suggest to comment the "LowPower.deepSleep(10000); // Sleep for 1 minute" line during testing.

Edit: Note, I'm not saying that code is optimal and could not be improved, but is should work. For example, if SD card is not present, SDcheck should enter into "while(1);" and not return. 

 

 

Hi @CBPerkins what battery are you using? If it's a 4000mAh battery, it should definitely last more than 24 hours I would've thought. Do you have a multimeter handy that you could use to take a current draw measurement? It sounds like it's using an awfully high amount of current...like it's stuck trying to take fixes all the time...worth checking if you can.

Cheers,

Rob

I am using a 3,300 mAh rechargeable lithium ion battery pack. The author did not say where they got their battery from, and as I needed the collars to weight less I got a smaller battery from amazon. I did just buy a battery from Adafruit and am going to compare the life of the devices when using that one and a battery from Amazon to see if that is the problem. However, I looked at the reviews online and a couple people stated that they used the battery for their Arduino projects and it worked great, so I assumed it was decent.

 

And yes the code they posted is the one I originally started using, but I couldn't get it to work for my device for longer than 30 seconds. Once I realized that I would have to use different code, I tried modifying it myself with the help of ChatGPT to make it work, which I know was not the best option but I thought it was worth a try. I posted the code I came up with in a reply above, and I am not sure if the device turns off when it is not looking for a fix.

The timer breakout board sounds amazing! I would love to learn more about it if you have time. One issue I was struggling with was trying to save battery when the GPS was not taking a fix while also still having the accelerometer continuously record data. My goal is to take a GPS location every hour, and have the accelerometer continuously record data at 32 hz (might change this to 16 hz). We are hoping to work with computer scientists to create a machine learning algorithm so that we can predict raccoon behavior based solely on the accelerometer sequences. This may be why I have been struggling so much, as I can get the GPS to work independently, but having the accelerometer continue to record has been difficult. Any help would be great! I am going to take a look at the "build your own data logger" course offered here, and am taking a coding in Python class this semester to hopefully build my skillset. But I will take any help anyone has to give for this project

hi

I had a quick look at your code, first you need to work with interrupt : timer interrupt for the gps and  interrupt pin INT1 or INT2 with the accelerometer. Second : used the fifo of the accelerometer, and configure it to have one of the interrupt pin to go high when the fifo is full. 

Working with interruption allow the program to go to sleep and only wakeup when needed (detection event interrupt).

Sd card consume a lot of power to write, you need to be careful how frequent to go write to it. 

One other thing the fifo depth of the accelerometer is 32 (checking it), which means with the sampling rate of 32hz, you can have 1sec of rest or time to write to the sd before 2 reading of the accelerometer.

cheers

virgil

 

To add to @V_Tail  , ensure that you close the file only when you have written 512 Bytes or multiple of 515 Bytes.  Any file system software will access the SD cards in chunks of 512 Bytes. So, if you open file, write ,say 32 Bytes, and close the file, the filesystem software will open the file, read the last block of 512 Bytes and add the new 32 Bytes to the end of data. As you close the file, the software will flash the whole block of 512 Bytes to disk. Consequently the sequence: open file, write 32 Bytes, close file, will 16 times read and write 512 Bytes. That is, your power consumption increases significantly (I suspect 16 times). Now, as your data will hardly line up with the 512 Byte boundary, it is sufficient to accumulate your data, say to fill up 8-16 kByte (multiple of 512) and then open file, write buffer, close file.

Perhaps it could be worth having something like a 'code sprint' for @jsstamn looking at their code as a starting point? I mean, my contributions would be paltry at best (although I am obviously happy to help wherever I can), but @V_Tail and you @WMXZ certainly sound like you know what's what, and if we could convince some others, maybe we could get the code into shape quick smart? Maybe at the end of an upcoming Variety Hour or other WILDLABS event? And/Or, could we post the code and begin tweaking it somewhere (or even point to places that need work etc.) online - is there an online code editor/IDE that people prefer? Maybe app.arduino/sketches ?

On the hardware side, I don't want to sound like a broken record, but the Adafruit timer board I mentioned above does a ton of heavy lifting re: sleep. I've been working on a hacked pet tracker that uses GPS and uploads data via LTE and the timer board puts it all to sleep (down to around 20uA) pretty easily. Still need code for what to do when the Arduino system wakes up obviously, but might be an easy solution to save a lot of power...

Cheers everyone,

Rob

 

A wildlabs hackathon would be sick actually @Rob_Appleby @StephODonnell 

 

I agree! It'd be a lotta fun!

@BrettMargoSupplies @Rob_Appleby @StephODonnell 

HI all,

sorry for falling off the chat so suddenly and for so long. I really appreciate all your comments, suggestions and enthusiasm. I was wrapped up in field work for another project, got overwhelmed with some things, and the timeline of this project shifted, but I am now back to moving my focus on my GPS project! I have enrolled in a coding class and am working with some students at another university to see if they have any insights on building the device. If doing a code sprint or some other activity is something other people are interested in I would be up for it! I will order that board that was mentioned and try to see if that is useful at all.