Demonstration of Class-A LoRaWAN device using NAMote-72

Dependencies:   LoRaWAN-lib mbed lib_mpl3115a2 lib_mma8451q lib_gps SX1272Lib

Dependents:   LoRaWAN-NAMote72-BVS-confirmed-tester-0-7v1_copy

LoRaWAN-NAMote72 Application Demo is a Class-A device example project using LoRaWAN-lib and SX1272Lib libraries.

This project is compliant with LoRaWAN V1.0.1 specification.

Comissioning.h (LoRaWAN Network Configuration)

The end-device can be activated in one of the two ways:

Over the Air (OTA) activation can be enabled as shown in the figure below.

The end-device must be configured with the following parameters:

• LORAWAN_DEVICE_EUI (8 Bytes) : Fist 3 Bytes is the Organizationally Unique Identifier (OUI) followed by 5 bytes of unique ID. If not defined by user, then the firmware automatically assigns one to the end-device
• LORAWAN_APPLICATION_EUI (8 Bytes)
• LORAWAN_APPLICATION_KEY (or DEVKEY) (16 Bytes)

Activation by Personalization (ABP) can be enabled as shown in the figure below.

The end-device must be configured with the following parameters:

• LORAWAN_DEVICE_ADDRESS (4 Bytes) : If not defined by user, then the firmware automatically assigns one to the end-device
• LORAWAN_NWKSKEY (16 Bytes)
• LORAWAN_APPSKEY (16 Bytes)

Config.h (LoRaWAN Communication Parameters)

• Mode of Operation : Hybrid If the end-device needs to be configured to operate over 8-channels, then Hybrid Mode needs to be enabled

• Mode of Operation : Frequency Hop If the end-device needs to be configured to operate over 64-channels, then Hybrid Mode needs to be disabled

• Delay between successive JOIN REQUESTs : The delay between successive Join Requests (until the end-device joins the network) can be configured using the parameter OVER_THE_AIR_ACTIVATION_DUTYCYCLE

• Inter-Frame Delay : One can change the delay between each frame transmission using APP_TX_DUTYCYCLE It is advisable that APP_TX_DUTYCYCLE is greater than or equal to 3sec.

• Data Rate : The data rate can be configured as per LoRaWAN specification using the paramter LORAWAN_DEFAULT_DATARATE. The range of values are DR_0, DR_1, DR_2, DR_3 and DR_4

• Confirmed/Unconfirmed Messages : The uplink message or payload can be chosen to be confirmed or unconfirmed using the parameter LORAWAN_CONFIRMED_MSG_ON. When set to 1, the transmitted messages need to be confirmed with an ACK by the network server in the subsequent RX window. When set to 0, no ACK is requested.

• ADR ON/OFF : The ADR can be enabled or disabled using the parameter LORAWAN_ADR_ON. When set to 1, ADR is enabled and disabled when set to 0.

• Application Port : The application port can be set using parameter LORAWAN_APP_PORT.

• Payload Length : The lenght of the payload (in bytes) to be transmitted can be configured using LORAWAN_APP_DATA_SIZE

• Transmit Power : The transmit power can be configured using LORAWAN_TX_POWER (LoRaMAC verifies if the set power is compliant with the LoRaWAN spec and FCC guidelines)

Main.cpp (Device State Machine)

The end-device state machine is defined.

• Initial State : Device is initialized.

• Join State : For OTA, Join Request is transmitted to the network until Join Accept is received by the end-device. Join event function is called that sets Red LED ON.

• Send State : Transmit payload frame is prepared. Tx event is called that blinks the Red LED indicating uplink transmission.

• Cycle State : Next packet transmission is scheduled

LoRaEventProc.cpp (Events and On-board Application)

Define events during Join, Tx & Rx. Prepare TX packet by appending with appropriate application data.

• PrepareLoRaFrame(uint8_t port ) : Prepare LoRa payload frame with on-board application data such as GPS, Temperature, Battery, etc. LoRa.ApplicationCall(AppType ) calls application AppType defined in LoRaApp.cpp. AppType is defined in LoRaApp.h

LoRaApp.cpp

User-defined applications such as GPS, Temp, Accelerometer, LED indications etc. Event based actions such as LED blink on Tx, LED toggle on downlink etc

LoRaDeviceStateProc.cpp

Process function calls corresponding to different Device states

LoRaMacLayerService.cpp

Define MAC Layer Services: MLME & MCPS

Serial Terminal Display

By using a serial port connection using applications such as teraterm or putty, one can view the status of the End-Device. Once the End-Device Joins the network, transmission parameters such as payload data, application port, message type etc. are displayed on the terminal.

Default Application Payload

This application defaults to sending uplink data to logical port 5. The application payload consists of:

Sample Application Payload Calculation for Longitude/Latitude

Payload => 00 19 F6 352BBA A94C20 FFFF

Temperature Calculation

19_H => 25₁₀

Temp = 25/2 = 12.5 ^oC

Battery Level

FF_H => 100 %

F6_H => 96.5 %

Longitude Calculation

longitude = A94C20_H => 11095072₁₀

longitudinal coordinate = -360 + (longitude₁₀ x 180/(2²³))

longitudinal coordinate = -121.93

Latitude Calculation

latitude = 352BBA_H = 3484602₁₀

latitude coordinate = (latitude₁₀ x 90/(2²³-1))

latitude coordinate = 37.39