Published January 29, 2021 © GPL3+

Explore Unlimited - Tracker for the explorers

A tracking-cum-SOS system for lost people

BeginnerShowcase (no instructions)5 hours547

Explore Unlimited - Tracker for the explorers

Things used in this project

Hardware components

Nordic Semiconductor nRF52840 Multi-Protocol SoC

Espressif Wemos D1 Mini

SparkFun Triple Axis Accelerometer and Gyro Breakout - MPU-6050

Maxim Integrated DS18B20 Programmable Resolution 1-Wire Digital Thermometer

Maxim Integrated MAX30102 High-Sensitivity Pulse Oximeter and Heart-Rate Sensor for Wearable Health

Software apps and online services

STMicroelectronics STM32CUBEPROG

Helium Console

Android Studio

Jaybird Labs NodeCode

Hand tools and fabrication machines

Soldering iron (generic)

Story

Hundreds of people worldwide die every year doing jobs that require them to go into places that are isolated from the 'connected' world. This includes but is not limited to mine-workers, underwater explorers, cave explorers, hikers, sailors, mountaineers, adventure tourists etc. The primary reason for most of the casualties is the inability to send an SOS message in time.

Existing solutions and Forethought

The only solutions that exist are SOS messages on cellular networks. However, the range of cellular networks is only this much and does encompass the challenging environments I have presented here. To solve this I want to build a health tracker cum SOS device for our explorers so that they can continue with their activities in a secure manner. The device would connect to a gateway at a suitable location and security personnel would be warned in time if there is a health emergency like a miner asphyxiation while stuck in a cave. This would help save lots of lives and people can then continue such activities without any fear which is also beneficial for the tourism industry which serves as a major source of income for many.

Solution

The health tracker will send health data ( such as heart beat, blood oxygen, movements) along with temperature, humidity, air quality to LoRa network through a gateway. In addition, I will use gyro and accelerator sensors to measure any sudden fall or movement. For sending SOS messages, a small push-button would also be placed. A module would also log GPS data when possible. The Helium Development Kit would receive data from all these sensors and send data packets at intervals of 5min to the HElium network. A web app made on Node Red would collect data from Helium Console and send notifications to a mobile app that alerts security personnel or safety agents

Impact of project

- Many lives would be saved
- Health data would be monitored and medical response would arrive in time
- Environmental data logged could be used in research
- Logged data would help tourism and exploration agencies

The first code on the board

#include "LoRaWAN.h"

const char *devEui = "FILL_ME_IN";
const char *appEui = "FILL_ME_IN";
const char *appKey = "FILL_ME_IN";

// Max Payload 53 Bytes for DR 1
const uint8_t payload[] = "Hello, World!";

void setup( void )
{
    Serial.begin(9600);
    
    while (!Serial) { }

    // US Region
    LoRaWAN.begin(US915);
    // Helium SubBand
    LoRaWAN.setSubBand(2);
    // Disable Adaptive Data Rate
    LoRaWAN.setADR(false);
    // Set Data Rate 1 - Max Payload 53 Bytes
    LoRaWAN.setDataRate(1);
    // Device IDs and Key
    LoRaWAN.joinOTAA(appEui, appKey, devEui);

    Serial.println("JOIN( )");
}

void loop( void )
{
    if (LoRaWAN.joined() && !LoRaWAN.busy())
    {
        Serial.print("TRANSMIT( ");
        Serial.print("TimeOnAir: ");
        Serial.print(LoRaWAN.getTimeOnAir());
        Serial.print(", NextTxTime: ");
        Serial.print(LoRaWAN.getNextTxTime());
        Serial.print(", MaxPayloadSize: ");
        Serial.print(LoRaWAN.getMaxPayloadSize());
        Serial.print(", DR: ");
        Serial.print(LoRaWAN.getDataRate());
        Serial.print(", TxPower: ");
        Serial.print(LoRaWAN.getTxPower(), 1);
        Serial.print("dbm, UpLinkCounter: ");
        Serial.print(LoRaWAN.getUpLinkCounter());
        Serial.print(", DownLinkCounter: ");
        Serial.print(LoRaWAN.getDownLinkCounter());
        Serial.println(" )");

        // Send Packet
        LoRaWAN.sendPacket(1, payload, sizeof(payload));
    }

    delay(20000); //20 Seconds
}