rbricheno / TTN-environment-monitor

Worshop about building an enironment monitor on The Things Network

TTN environment monitor

By David Batey, Josh Milroy and Rob Bricheno

Contents

1. Introduction
2. Getting Started
3. Testing LoRaWAN
4. Adding the BME280
5. Sending BME280 data into The Things Network
6. Adding a MyDevices dashboard
7. Activation by personalisation method

Introduction

In this workshop we make a LoRaWAN environment monitor to monitor pressure, temperature and humidity via long range radio.

For the hardware, we will use an Arduino, a LoRa shield, and a BME280 sensor.

For the software, we will create Arduino sketches that send sensor data over LoRaWAN into The Things Network using the Cayenne LPP protocol. We then configure a cloud dashboard to receive the data from the sensor using the MyDevices Cayenne platform.

Getting started

For this project you will need the following hardware:

• Arduino Uno - https://store.arduino.cc/arduino-uno-rev3 - or a clone of an Arduino Uno board should work fine in our experience.

• BME280 pressure, temperature and humidity sensor in a breakout board - https://www.bosch-sensortec.com/bst/products/all_products/bme280 - You can find these on Amazon or eBay. Ours runs at 5V. To follow the workshop, we will be using the I2C protocol to communicate with the sensor.

• UNIROI Starter Kit (or another Arduino starter kit) - http://uniroi.net/a/Products/20190401/70.html - the only things we're using from here are jumper wires and a breadboard.

• Pi Supply Arduino LoRa node shield (based on RAK wireless RAK811) - https://uk.pi-supply.com/products/iot-lora-node-shield

Firstly, you should install the Arduino IDE from the Arduino website (https://www.arduino.cc/en/main/software).

Then you should create a The Things Network account on their website (https://account.thethingsnetwork.org/register).

After this, you will need to register your application at https://console.thethingsnetwork.org/applications/add. Here, you need to fill in the application ID and description. You can just make things up for both of these fields.

Next, you will need to register your device at https://console.thethingsnetwork.org/applications/application/devices/register. You have to enter a Device ID (wich, again, you can just make up) and click the symbol next the Device EUI text box (to cause the Device EUI to be automatically generated).

Make a note of the Device EUI, Application EUI, and Application Key as you will need these to connect your sensor to The Things Network.

Testing LoRaWAN

Now we will test "Over The Air Activation" on the Arduino and shield. Connect the shield to the top of your Arduino Uno as shown here:

You will need to download and install the RAK811 Arduino Library from https://github.com/PiSupply/RAK811-Arduino . Download the RAK811-Arduino repository as a Zip file and in the Arduino IDE use "Sketch -> Add Library -> Add .ZIP library" and add the downloaded zip file.

If you have not used your Pi Supply LoRa Node Shield for Arduino before, be wary that some shields work at faster speed, so the baud rate must be changed. To do this, upload the Setbaudrate.ino which can be found in the "examples" folder of the zip file you just downloaded, or downloaded from https://github.com/PiSupply/RAK811-Arduino/tree/master/examples/Setbaudrate . This will set the baud rate to 9600bps, in line with the rest of the code here. There is no harm in doing this, even if you think the baud rate is already correct, so we strongly recommend you run Setbaudrate.ino at least once before you continue with the workshop to avoid unexpected problems.

Now, in the Arduino IDE, create a new sketch and enter this code:

#include "RAK811.h"
#include "SoftwareSerial.h"
#define WORK_MODE LoRaWAN   //  LoRaWAN or LoRaP2P
#define JOIN_MODE OTAA    //  OTAA or ABP
#if JOIN_MODE == OTAA
String DevEui = "<PUT YOUR KEY HERE FROM TTN CONSOLE>"; // Fill this out
String AppEui = "<PUT YOUR KEY HERE FROM TTN CONSOLE>"; // Fill this out
String AppKey = "<PUT YOUR KEY HERE FROM TTN CONSOLE>"; // Fill This out
#else JOIN_MODE == ABP
String NwkSKey = "";
String AppSKey = "";
String DevAddr = "";
#endif
#define TXpin 11   // Set the virtual serial port pins
#define RXpin 10
#define DebugSerial Serial
SoftwareSerial RAKSerial(RXpin,TXpin);    // Declare a virtual serial port
char* buffer = (char*) "72616B776972656C657373";
int RESET_PIN = 12;
bool InitLoRaWAN(void);
RAK811 RAKLoRa(RAKSerial,DebugSerial);
 
 
void setup() {
  // Define Reset Pin
  pinMode(RESET_PIN, OUTPUT);
  
  // Setup Debug Serial on USB Port
  DebugSerial.begin(9600);
  while(DebugSerial.read()>= 0) {}
  while(!DebugSerial);
  //Print debug info
  DebugSerial.println("StartUP");
  DebugSerial.println("Reset");
  //Reset the RAK Module
  digitalWrite(RESET_PIN, LOW);   // turn the pin low to Reset
  digitalWrite(RESET_PIN, HIGH);    // then high to enable
  DebugSerial.println("Success");
  RAKSerial.begin(9600); // Arduino Shield
  delay(100);
  DebugSerial.println(RAKLoRa.rk_getVersion());
  delay(200);
  DebugSerial.println(RAKLoRa.rk_getBand());
  delay(200);
 
  while (!InitLoRaWAN());
}

bool InitLoRaWAN(void)
{
  RAKLoRa.rk_setWorkingMode(WORK_MODE);
  RAKLoRa.rk_recvData();
  RAKLoRa.rk_recvData();
  if ( RAKLoRa.rk_recvData() == "OK")
  {
    if (RAKLoRa.rk_initOTAA(DevEui, AppEui, AppKey))
    {
      DebugSerial.println("You init OTAA parameter is OK!");
      while (RAKLoRa.rk_joinLoRaNetwork(JOIN_MODE))
      {
        bool flag = false;
        for (unsigned long start = millis(); millis() - start < 90000L;)
        {
          String ret = RAKLoRa.rk_recvData();
          if (ret.startsWith(STATUS_JOINED_SUCCESS))
          {
            DebugSerial.println("You join Network success!");
            return true;
          }
          else if (ret.startsWith(STATUS_RX2_TIMEOUT) || ret.startsWith(STATUS_JOINED_FAILED))
          {
            DebugSerial.println("You join Network Fail!");
            flag = true;
            DebugSerial.println("The device will try to join again after 5s");
            delay(5000);
          }
        }
        if (flag == false)
        {
          DebugSerial.println("Pleases Reset the module!");
          delay(1000);
          return false;
        }
      }
    }
  }
  return false;
}
 
void loop() {
  int packetsflag = 1; // 0: unconfirmed packets, 1: confirmed packets
  if (RAKLoRa.rk_sendData(packetsflag, 1, buffer))
  {
    for (unsigned long start = millis(); millis() - start < 90000L;)
    {
      String ret = RAKLoRa.rk_recvData();
      if (ret.startsWith(STATUS_TX_COMFIRMED) || ret.startsWith(STATUS_TX_UNCOMFIRMED))
      {
        DebugSerial.println("Send data ok!");
        delay(5000);
        return;
      }
    }
    DebugSerial.println("Send data error!");
    while (1);
  }
}

Fill out the Dev Eui, App Eui and App Key which you can find on the TTN website (https://console.thethingsnetwork.org/applications/application/devices/device ).

Run this code on your Arduino by pressing “Upload” and then open the TTN website. In the TTN website go the data page (https://console.thethingsnetwork.org/applications/application/devices/device/data). Here, the payload should state “72616B776972656C657373”.

Adding the BME280

Next we will test the BME280 sensor. Either plug the sensor into the arduino directly or the same pins on the shield. The pins should be connected:

BME280	Arduino
VIN	5V
GND	GND
SCL	A5
SDA	A4

It should look something like this when all connected up:

You will need to install the Adafruit BME280 library and Adafruit unified sensors library, both of which should be available to find in the "Add library" tool within the Arduino IDE.

Then type this code in a new Arduino window:

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>
 
#define SEALEVELPRESSURE_HPA (1013.25)
 
Adafruit_BME280 bme; // I2C
 
unsigned long delayTime;
 
void setup() {
    Serial.begin(9600);
    while(!Serial);    // time to get serial running
    Serial.println(F("BME280 test"));
 
    unsigned status;
    
    // default settings
    // status = bme.begin();
    // We found that since version 2 of the Adafruit library
    // we have to initialise our (non-Adafruit-branded) I2C
    // BME280 like this:
    status = bme.begin(0x76, &Wire);
    if (!status) {
        Serial.println("Could not find a valid BME280 sensor, check wiring, address, sensor ID!");
        Serial.print("SensorID was: 0x"); Serial.println(bme.sensorID(),16);
        Serial.print("        ID of 0xFF probably means a bad address, a BMP 180 or BMP 085\n");
        Serial.print("   ID of 0x56-0x58 represents a BMP 280,\n");
        Serial.print("        ID of 0x60 represents a BME 280.\n");
        Serial.print("        ID of 0x61 represents a BME 680.\n");
        while (1);
    }
    
    Serial.println("-- Default Test --");
    delayTime = 1000;
 
    Serial.println();
}
 
 
void loop() { 
    printValues();
    delay(delayTime);
}
 
 
void printValues() {
    Serial.print("Temperature = ");
    Serial.print(bme.readTemperature());
    Serial.println(" *C");
 
    Serial.print("Pressure = ");
 
    Serial.print(bme.readPressure() / 100.0F);
    Serial.println(" hPa");
 
    Serial.print("Approx. Altitude = ");
    Serial.print(bme.readAltitude(SEALEVELPRESSURE_HPA));
    Serial.println(" m");
 
    Serial.print("Humidity = ");
    Serial.print(bme.readHumidity());
    Serial.println(" %");
 
    Serial.println();
}

This program should return 3 values (Temperature, Humidity and Pressure) into the serial monitor which can be accessed by Ctrl+Shift+M.

Sending BME280 data into The Things Network

The next step is to send the BME 280 data to TTN in Cayenne format. This is done through this code:

#include <CayenneLPP.h>
#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>
#include "RAK811.h"
#include "SoftwareSerial.h"
#define WORK_MODE LoRaWAN   //  LoRaWAN or LoRaP2P
#define JOIN_MODE OTAA    //  OTAA or ABP
#if JOIN_MODE == OTAA
String DevEui = "<PUT YOUR KEY HERE FROM TTN CONSOLE>"; // Fill this out
String AppEui = "<PUT YOUR KEY HERE FROM TTN CONSOLE>"; // Fill this out
String AppKey = "<PUT YOUR KEY HERE FROM TTN CONSOLE>"; // Fill This out
#endif
#define TXpin 11   // Set the virtual serial port pins
#define RXpin 10
#define DebugSerial Serial
 
Adafruit_BME280 bme; // I2C
CayenneLPP lpp(51);
SoftwareSerial RAKSerial(RXpin,TXpin);    // Declare a virtual serial port
 
int RESET_PIN = 12;
bool InitLoRaWAN(void);
RAK811 RAKLoRa(RAKSerial,DebugSerial);
 
void setup() {
  //Define Reset Pin
  pinMode(RESET_PIN, OUTPUT);
  //Setup Debug Serial on USB Port
  DebugSerial.begin(9600);
  while(DebugSerial.read()>= 0) {}
  while(!DebugSerial);
  //Print debug info
  DebugSerial.println("StartUP");
  DebugSerial.println("Reset");
  //Reset the RAK Module
  digitalWrite(RESET_PIN, LOW);   // turn the pin low to Reset
  digitalWrite(RESET_PIN, HIGH);    // then high to enable
  DebugSerial.println("Success");
  RAKSerial.begin(9600); // Arduino Shield
  delay(100);
  DebugSerial.println(RAKLoRa.rk_getVersion());
  delay(200);
  DebugSerial.println(RAKLoRa.rk_getBand());
  delay(200);
 
  while (!InitLoRaWAN());

  bme.begin(0x76, &Wire);  
}

bool InitLoRaWAN(void)
{
  RAKLoRa.rk_setWorkingMode(WORK_MODE);
  RAKLoRa.rk_recvData();
  RAKLoRa.rk_recvData();
  if ( RAKLoRa.rk_recvData() == "OK")
  {
 
    if (RAKLoRa.rk_initOTAA(DevEui, AppEui, AppKey))
    {
      DebugSerial.println("You init OTAA parameter is OK!");
      while (RAKLoRa.rk_joinLoRaNetwork(JOIN_MODE))
      {
        bool flag = false;
        for (unsigned long start = millis(); millis() - start < 90000L;)
        {
          String ret = RAKLoRa.rk_recvData();
          if (ret.startsWith(STATUS_JOINED_SUCCESS))
          {
            DebugSerial.println("You join Network success!");
            return true;
          }
          else if (ret.startsWith(STATUS_RX2_TIMEOUT) || ret.startsWith(STATUS_JOINED_FAILED))
          {
            DebugSerial.println("You join Network Fail!");
            flag = true;
            DebugSerial.println("The device will try to join again after 5s");
            delay(5000);
          }
        }
        if (flag == false)
        {
          DebugSerial.println("Pleases Reset the module!");
          delay(1000);
          return false;
        }
      }
    }
  }
     return false;
}
 
void loop() {
 
  Serial.print("Temperature = ");
  Serial.print(bme.readTemperature());
  Serial.println(" *C");
 
  Serial.print("Pressure = ");
  Serial.print( bme.readPressure());
  Serial.println(" hpa");
 
  Serial.print("Humidity = ");
  Serial.print( bme.readHumidity());
  Serial.println(" rh");
 
 
  lpp.reset();
  lpp.addTemperature(1, bme.readTemperature());
  lpp.addRelativeHumidity(2, bme.readHumidity());
  lpp.addBarometricPressure(3, bme.readPressure());
  
  int packetsflag = 1; // 0: unconfirmed packets, 1: confirmed packets
  if (RAKLoRa.rk_sendBytes(packetsflag, 1, lpp.getBuffer(), lpp.getSize()))
  {
    for (unsigned long start = millis(); millis() - start < 90000L;)
    {
      String ret = RAKLoRa.rk_recvData();
      if (ret.startsWith(STATUS_TX_COMFIRMED) || ret.startsWith(STATUS_TX_UNCOMFIRMED))
      {
        DebugSerial.println("Send data ok!");
        delay(60000);
        return;
      }
    }
    DebugSerial.println("Send data error!");
    while (1);
  }
}

Fill out the Dev Eui, App Eui and App Key which you can find on the TTN website (https://console.thethingsnetwork.org/applications/application/devices/device ). Then on the TTN website, click on the payload format tab (https://console.thethingsnetwork.org/applications/application/payload-formats). Then click on the drop-down menu and choose Cayenne. Now, you can upload the program to the Arduino and the data should appear in the payloads.

Adding a MyDevices dashboard

Finally, click on the Intergrations tab (https://console.thethingsnetwork.org/applications/application/integrations) and click “add integration” (https://console.thethingsnetwork.org/applications/application/integrations/create).

Choose myDevices (https://console.thethingsnetwork.org/applications/application/integrations/create/http-cayenne) and enter a Process ID (you can just make something up) and click on the access key drop-down box and choose default key.

Create an account at https://accounts.mydevices.com/auth/realms/cayenne/login-actions/registration?client_id=cayenne-web-app&tab_id=27_MIrlvDiU .

Choose LoRa (https://cayenne.mydevices.com/cayenne/dashboard/first-visit/lora) and then scroll down and choose The Things Network (Under the networks sidebar) and then choose Cayenne Cayenne LPP.

Enter your Device Eui from the TTN website (https://console.thethingsnetwork.org/applications/application/devices/device ) and then press add device.

You should then run the program on your Arduino and the data should appear on myDevices dashboard and be updated every minute (https://cayenne.mydevices.com/cayenne/dashboard/lora/).

Activation by personalisation method

If you can't get OTAA to work (because you have poor downlink reception from the gateway for example) then you can use the following code instead to activate your node using ABP and still complete the workshop.

#include <CayenneLPP.h>
#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>
#include "RAK811.h"
#include "SoftwareSerial.h"
#define WORK_MODE LoRaWAN   //  LoRaWAN or LoRaP2P
#define JOIN_MODE ABP   //  OTAA or ABP
#if JOIN_MODE == ABP
String NwkSKey = ""; // Fill this out
String AppSKey = ""; // Fill this out
String DevAddr = ""; // Fill this out
#endif
#define TXpin 11   // Set the virtual serial port pins
#define RXpin 10
#define DebugSerial Serial

Adafruit_BME280 bme; // I2C
CayenneLPP lpp(51);
SoftwareSerial RAKSerial(RXpin,TXpin);    // Declare a virtual serial port

int RESET_PIN = 12;
bool InitLoRaWAN(void);
RAK811 RAKLoRa(RAKSerial,DebugSerial);

void setup() {
  //Define Reset Pin
  pinMode(RESET_PIN, OUTPUT);
  //Setup Debug Serial on USB Port
  DebugSerial.begin(9600);
  while(DebugSerial.read()>= 0) {}
  while(!DebugSerial);
  //Print debug info
  DebugSerial.println("StartUP");
  DebugSerial.println("Reset");
  //Reset the RAK Module
  digitalWrite(RESET_PIN, LOW);   // turn the pin low to Reset
  digitalWrite(RESET_PIN, HIGH);    // then high to enable
  DebugSerial.println("Success");
  RAKSerial.begin(115200); // Arduino Shield. The number can be changed! Search for serial speeds
  delay(100);
  DebugSerial.println(RAKLoRa.rk_getVersion());
  delay(200);
  DebugSerial.println(RAKLoRa.rk_getBand());
  delay(200);

  while (!InitLoRaWAN());

  bme.begin(0x76, &Wire);  


}
bool InitLoRaWAN(void)
{
  RAKLoRa.rk_reset(1);
  RAKLoRa.rk_setWorkingMode(WORK_MODE);
  RAKLoRa.rk_recvData();
  RAKLoRa.rk_recvData();
  if ( RAKLoRa.rk_recvData() == "OK")
  {
    if (RAKLoRa.rk_initABP(DevAddr, NwkSKey, AppSKey))
    {
      Serial.println("You init ABP parameter is OK!");
      if (RAKLoRa.rk_joinLoRaNetwork(JOIN_MODE))
      {
        Serial.println("You join Network success!");
        return true;
      }
    }
  }
  return false;
}

void loop() {

  Serial.print("Temperature = ");
  Serial.print(bme.readTemperature());
  Serial.println(" *C");
  Serial.print("Pressure = ");
  Serial.print(bme.readPressure() / 100.0F);
  Serial.println(" hPa");
  Serial.print("Humidity = ");
  Serial.print(bme.readHumidity());
  Serial.println(" %");

  lpp.reset();
  lpp.addTemperature(1, bme.readTemperature());
  lpp.addBarometricPressure(2, bme.readPressure());
  lpp.addRelativeHumidity(3, bme.readHumidity());
    
  int packetsflag = 1; // 0: unconfirmed packets, 1: confirmed packets
  if (RAKLoRa.rk_sendBytes(packetsflag, 1, lpp.getBuffer(), lpp.getSize()))
  {
    for (unsigned long start = millis(); millis() - start < 6000L;)
    {
      String ret = RAKLoRa.rk_recvData();
      if (ret.startsWith(STATUS_TX_COMFIRMED) || ret.startsWith(STATUS_TX_UNCOMFIRMED))
      {
        DebugSerial.println("Send data ok!");
        delay(5000);
        return;
      }
    }
    DebugSerial.println("Send data error!");
        delay(5000);
  }
  RAKLoRa.rk_recvData();

  
}

We hope you had fun!

This work is licensed under Creative Commons Attribution 4.0 https://creativecommons.org/licenses/by/4.0/legalcode