Welcome to the ESIB IoT Challenge. In this challenge, you will be designing and prototyping the first IoT services based on a LoRaWAN network.

During this challenge, you will benefit from the first experimental platform implementing an end-to-end LoRaWAN solution in Lebanon. The platform consists of the following elements:

• Devices that communicate to one or more gateways via a wireless interface using single hop LoRa and implementing the LoRaWAN protocol. These devices are physically connected to sensors that generate data.
• Gateways or base stations that forward frames between the devices and the network server. Gateways are connected to the network server via IP interfaces.
• A LoRAWAN backend that implements the network server functions and provides frame control and security.
• Applications that enable to visualize and store the sensor data obtained from the devices.

Figure 1. Architecture of the LoRaWAN Platform

In a LoRaWAN network, the devices communicate with a Network Server through the gateway. The backend installed in the platform is based on an open-source LoRaWAN network-server https://www.loraserver.io. A web interface is available for configuring the applications and devices on the platform (https://212.98.XX.XX:8080).

Figure 2. Loraserver web interface

Start by choosing the application named NTRE-1617 to create a new node. You should provide the following information:

• A unique node name: NTRE-GX (where X is your group number)
• The node description
• A unique device EUI on 64 bits: Random identifiers can be generated on https://www.random.org/bytes/
• The application EUI on 64 bits: 0badde1cafe2deca.
• A unique application key on 128 bits also obtained by random generation.

Make sure that the ABP activation button is unchecked, in order to enable OTAA join method. Finally, in advanced network settings, choose the receive window RX2.

Devices in the LoRaWAN platform are implemented on Arduino boards with Dragino shields. The combined module as well as the basic configuration steps are presented in Simple Prototype of LoRa Communications.

Start by verifying the installation on your PC of the latest Arduino IDE. Drop the Arduino LMIC library in the corresponding folder. These tools are provided at the beginning of the challenge. Open the example sketch example-code-ntre-iot-challenge.ino with Arduino IDE.

Now you should configure your device with the same identifiers APPEUI, DEVEUI, and APPKEY as in the backend:

static const u1_t PROGMEM APPEUI[8]= { };
void os_getArtEui (u1_t* buf) { memcpy_P(buf, APPEUI, 8);}
 
// This should also be in little endian format, see above.
static const u1_t PROGMEM DEVEUI[8]= { };
void os_getDevEui (u1_t* buf) { memcpy_P(buf, DEVEUI, 8);}
 
static const u1_t PROGMEM APPKEY[16] = { };
void os_getDevKey (u1_t* buf) {  memcpy_P(buf, APPKEY, 16);}

Let us analyze to radio parameters in the sketch by answering the following questions.

The LMIC library defines a set of events corresponding to the protocol machine state. These events appear in the onEvent() function.

Finally let us look at the message sending on the device.

Now you are ready to compile the sketch and upload it to the LoRaWAN device. Connect the device a USB port on your PC, choose the board type as Arduino/Genuino Mega 2560 and select the corresponding port. Compile and upload!

Open the serial monitor in the Arduino IDE at 115200 baud and analyse the debug messages.

Getting back to the backend, you can monitor some important information related to your device. Click on the corresponding node session.

mqtt-spy is an open source utility intended to help you with monitoring activity on MQTT topics. It has been designed to deal with high volumes of messages, as well as occasional publications. mqtt-spy is a JavaFX application, so it should work on any operating system with an appropriate version of Java 8 installed. A very useful tutorial is available on https://github.com/eclipse/paho.mqtt-spy/wiki. You can use mqtt-spy to debug the messages received from the LoRaWAN devices. The tool is provided at the beginning of the challenge. After starting the application, configure a new connection to the MQTT broker by simply adding the IP address of the broker in the Server URI field. Now you can subscribe to any MQTT topic. If you want to receive all messages arriving at the backend, you can use the generic topic #. You can also limit to the topic including the messages of any specific device: application/APPLICATION_ID/node/DEVICE_EUI/rx.

If you need to send data to your device, you should publish the encoded message in the corresponding topic application/APPLICATION_ID/node/DEVICE_EUI/tx as follows:

{
    "reference": "abcd1234",                  // reference which will be used on ack or error (this can be a random string)
    "confirmed": false,                        // whether the payload must be sent as confirmed data down or not
    "fPort": 10,                              // FPort to use (must be > 0)
    "data": "...."                            // base64 encoded data (plaintext, will be encrypted by LoRa Server)
}

I can send data from the device to the application.

I can send data from the application to the device.

I can tune the LoRa radio parameters and assess the results.

These two commands can be helpful when used after the join event:

LMIC_disableChannel(N);
LMIC_setDrTxpow(DR_SF12,14);

I can use different sensors to send data from the device: PIR, moisture, temperature, light, etc.

This is a mandatory challenge. It consists of using Node-RED to receive data from the sensors (via MQTT) and send it to emoncms for visualization.

You have to take control on the devices. Use some scripting to send commands or tune some parameters on the devices.

You have to store the sensor data in a database. Use Node-RED to inject data in a (influx) database.

You have to implement a radio coverage test on the campus.

You have to implement a chat bot designed for working with Google Hangouts. The bot answers requests and reveals sensors data.