ble-mqtt-bridge

The ble-mqtt-bridge facilitates the forwarding of values between Bluetooth Low Energy (BLE) characteristics and MQTT messages in both directions:

The bridge can automatically connect to a BLE device and subscribe to or iteratively read (poll) a specific characteristic. Whenever a new value is read, the bridge will forward it to the MQTT broker with the corresponding topic. The broker can then distribute the value to other interested parties on the network.

The bridge can also be configured, to subscribe to MQTT messages with a configurable topic from a MQTT broker and forward their content to a BLE characteristic.

Requirements

tinyb

If you compiled libtinyb.so from the sources, it will by default be located in /usr/local/lib, therefore that path must be in your LDFLAGS. You can add it to the Makefile

LDFLAGS += -L/usr/local/lib

or configure it globally e.g. by adding

 export LDFLAGS=${LDFLAGS}:-L/usr/local/lib

to your ~/.bashrc.

nlohmann/json

The configuration format of the floorsensor daemon is JSON. In order to compile floorsensord, you need nlohmann/json. It will be installed to /usr/local.

$ git clone https://github.com/nlohmann/json.git
...
$ cd json
$ mkdir build
$ cd build
$ cmake ..
...
$ make 
...
$ make test
...
$ sudo make install
...

mosquitto

In order to being able to publish messages, you need to have a MQTT broker running somewhere, in the simplest case on your local host.

We used Eclipse's mosquitto daemon, running on port 1883.

You can install it on ubuntu/debian with

$ apt install mosquitto mosquitto-clients libmosquittopp-dev

or with a docker image

$ apt install mosquitto-clients libmosquittopp-dev

$ docker run -it -p 1883:1883 -p 9001:9001  --name mosquitto eclipse-mosquitto 

The mosquitto.conf could for example look like this:

listener 1883 127.0.0.1
allow_anonymous true

pid_file /var/run/mosquitto.pid

persistence false

log_type information
log_type notice
log_type warning
log_type error

log_dest stdout
log_dest file /var/log/mosquitto/mosquitto.log

Programs

General Configuration Options

-v n   Set loguru::g_stderr_verbosity level. Examples:
    -v 3        Show verbosity level 3 and lower.
    -v 0        Only show INFO, WARNING, ERROR, FATAL (default).
    -v INFO     Only show INFO, WARNING, ERROR, FATAL (default).
    -v WARNING  Only show WARNING, ERROR, FATAL.
    -v ERROR    Only show ERROR, FATAL.
    -v FATAL    Only show FATAL.
    -v OFF      Turn off logging to stderr.

from BLE/GATT to MQTT

• Daemon to read values from the floor-sensors used in the sentient-project from Baumhaus Berlin

from MQTT to BLE/GATT

• Daemon to control a legacy alarm-light
• Daemon to steer an driving robot

from USB to MQTT

• Daemon that reads values from an USB Joystick

from serial to MQTT

• Daemon that reads values from an SDS001 dustsensor

Configutation generators

• configuration from floorsensod

Playground

• Playground for json-mapping
• Playground for logging