MQTT-SN gateway for linux based operating systems. Unlike most other transparent MQTT-SN Gateway implementations it is a aggregating Gateway. From the beginning it is designed for bare-metal environments without a heap.

It glues the core-mqtt-sn-gateway together with transmission technology implementations, MQTT-Client and the core component cmplementations (LinuxGateway, LinuxLogger, LinuxPersistent, LinuxSystem).

At the moment we support:

• x86
• ARM (especially Raspberry Pi)
• OpenWrt (Dragino LoRa Gateway)

For x86 we only support Ethernet (UDP & TCP) and WiFi (UDP & TCP). On ARM (Raspberry Pi) there is additionally ZigBee, LoRa and BLE. Additionally we support OpenWrt (Dragino LoRa Gateway) with LoRa. See the Transmission Technology to Architecture Matrix.

* needs additional transmission hardware

• ✅ implemented and tested
• ❎ not implemented yet

This is the section for all of you who only want to use the gateway. Get a pre-built binary from here.

The gateway needs the following configurations files: MQTT.CON, TOPICS.PRE. Put these files into the execution directory (next to the binary). The linux-mqtt-sn-gateway will pick and create needed files there.

The MQTT.CON file is the configuration file of the MQTT client. It is Key Value based. Every line contains one key with the corresponding value after the first space.

The following values are NOT optional:

• brokeraddress - IP address of the MQTT Broker, DNS or mDNS are not implemented but on the TODO list.
• brokerport - Port of the MQTT Broker
• clientid - MQTT client's id
• gatewayid - Id of the gateway in the WSN

You can provide a will for the gateway (optional):

• willtopic - topic of the will message
• willmessage - payload of the willmessage (only ASCII supported)
• willqos - quality of service of the will
• willretain - retain of the will

Note that you need to provide all values of the will (there are no default values) or the gateway will connect without a will.

Example MQTT.CON file:

brokeraddress 192.168.178.33
brokerport 1884
clientid mqtt-sn linux gateway
willtopic /mqtt/sn/gateway
willmessage /mqtt-sn linux gateway offline
willqos 1
willretain 0
gatewayid 2

The TOPCIS.PRE file is the list of predefined MQTT topics of the gateway. Entries are space separated. Each entry starts with the topic id followed by the topic name. If a topic id is not unqiue in the file, the first topic if found by the gateway (starting at the beginning of the file) will be used.

Example TOPICS.PRE file:

50 /some/predefined/topic
20 /another/predefined/topic

Clone the repository and initialize CMAKE with the Transmission Protocol (e.g. UDP)

git clone --recursive https://github.com/S3ler/linux-mqtt-sn-gateway.git
cmake -G"Unix Makefiles" -DCMAKE_BUILD_TYPE=Debug -DTRANSMISSION_PROTOCOL=UDP
make linux-mqtt-sn-gateway

done.

For testing see the test-mqtt-sn-gateway project.

At the moment we do not configure cmake for cross-compilation. The easiest way to get started is to work on a Raspberry Pi directly. You need a least CMake Version 3.0 for the project. Maybe you need to compile CMake on the Raspberry Pi before starting development.

The other steps are the same as for x86: Clone the repository and initialize CMAKE with the Transmission Protocol (e.g. UDP)

git clone --recursive https://github.com/S3ler/linux-mqtt-sn-gateway.git
cmake -G"Unix Makefiles" -DCMAKE_BUILD_TYPE=Debug -DTRANSMISSION_PROTOCOL=UDP
make linux-mqtt-sn-gateway

done.

When running or developing the gateway with LoRa you need additional Hardware. For testing you need Hardware for a client device (see test-mqtt-sn-gateway - Serial Lora Client).

Clone the repository and initialize CMAKE with the platform, Transmission Protocol (RPI_LoRa) and address

git clone --recursive https://github.com/S3ler/linux-mqtt-sn-gateway.git
cmake -G"Unix Makefiles" -DCMAKE_BUILD_TYPE=Debug -DTRANSMISSION_PROTOCOL=RPI_LORA -DOWN_ADDRESS=1
make linux-mqtt-sn-gateway

done.

We implement the LoRa linux-mqtt-sn-gateway on a Raspberry Pi 3. We develop, test and run out gateway with the following hardware:

• Raspberry Pi 3
• Dragino Lora/GPS HAT 868 Mhz

Connect Pin 22 to Pin 24 on the Dragino Lora/GPS HAT. E.g. by soldering stackable 0.1" (2.54mm) female header and connect them by a jumper. For more information see:

Example4 -- http://wiki.dragino.com/index.php?title=Lora/GPS_HAT

Unfortunately there is a problem with newer Raspbian version after Raspbian Jessie. A change in the SPI API used by wiringPi used by RadioHead (used by the linux-mqtt-sn-gateway) creates problems with the initialization of the LoRa chip. We tested the linux-mqtt-sn-gateway with Raspbian Jessie (2017-07-05).

Do not forget to enable SPI on the Raspberry Pi with

sudo raspi-config

Get a pre-built binary from here. Or obtain them by wget:

wget TODO
untar TODO

After you got your hardware and configured your RPI The easiest way to get started is to work on a Raspberry Pi directly. At the moment we do not configure cmake for cross-compilation.

You need a least CMake Version 3.0 for the project. Maybe you need to compile CMake on the Raspberry Pi before starting development.

The other steps are the same as for x86: Clone the repository and initialize CMAKE with the Transmission Protocol (e.g. LoRa)

git clone --recursive https://github.com/S3ler/linux-mqtt-sn-gateway.git
cmake -G"Unix Makefiles" -DCMAKE_BUILD_TYPE=Debug -DTRANSMISSION_PROTOCOL=LORA
make linux-mqtt-sn-gateway

done. Happy coding.

Unfortunately we do not support all features defined in the MQTT-SN Standard.

Not Implemented (yet):

• wildcard subscription
• will update procedure
• retransmission procedure
• QoS 2 publishing
• MQTT-SN Forward Encapsulation

Everything else is implemented and tested (see test-mqtt-sn-gateway project).

We use four project as git submodules:

• core-mqtt-sn-gateway
• arduino-linux-abstraction
• mqtt-sn-sockets
• SimpleBluetoothLowEnergySocket

It runs only on Linux system but it is written against the Arduino Framework by using Linux based fake implementations for Arduino functions and libraris. It runs (successfully) on a NodeMCU with Arduino Core and a SPI SD-Card reader. This implementation is a aggregating gateway for MQTT-SN. The aim of MQTT-SN is to support Wireless Sensor Networks (WSNs) with very large numbers of battery-operated sensors and actuators (SAs). This gateway is designed with platform independence in mind. Other MQTT-SN gateway implementation at least need a operating system (or only bridge messages). To fulfill the requierement the implementation shall use little RAM, no dynamic memory allocation, platform and hardware portability by interfaces. Further it does not rely on any physical layer, media access control (e.g IEEE 802.15.4), network layer (e.g. 6LoWPAN) or transport layer (e.g. UDP/TCP) standard or implementation.

For Bluetooth development install:

apt install pkg-config
apt install libglib2.0-dev
apt install libbluetooth-dev

For enabling blutooth see here: https://stackoverflow.com/questions/41351514/leadvertisingmanager1-missing-from-dbus-objectmanager-getmanagedobjects