/esp-idf-mqtt-broker

MQTT Broker for esp-idf

Primary LanguageCMIT LicenseMIT

esp-idf-mqtt-broker

MQTT Broker for esp-idf.
This project use Mongoose networking library.
I forked from here.
However, with the release of mongoose ver7, I rewrote it.
Your fork is welcome.

Installation overview

  1. In this project directory, create a components directory.

  2. In the components directory, clone Mongoose:

git clone https://github.com/cesanta/mongoose.git
  1. In the new Mongoose directory, create a CMakeLists.txt file containing:
idf_component_register(SRCS "mongoose.c" INCLUDE_DIRS ".")
  1. Compile this project.

Installation for ESP32

git clone https://github.com/nopnop2002/esp-idf-mqtt-broker
cd esp-idf-mqtt-broker
mkdir -p components
cd components/
git clone https://github.com/cesanta/mongoose.git
cd mongoose/
echo "idf_component_register(SRCS \"mongoose.c\" INCLUDE_DIRS \".\")" > CMakeLists.txt
cd ../..
idf.py set-target esp32
idf.py menuconfig
idf.py flash monitor

Installation for ESP32-S2

git clone https://github.com/nopnop2002/esp-idf-mqtt-broker
cd esp-idf-mqtt-broker
mkdir -p components
cd components/
git clone https://github.com/cesanta/mongoose.git
cd mongoose/
echo "idf_component_register(SRCS \"mongoose.c\" INCLUDE_DIRS \".\")" > CMakeLists.txt
cd ../..
idf.py set-target esp32s2
idf.py menuconfig
idf.py flash monitor

Software requiment

  • mongoose ver7.3 or later.
    This is because mg_mqtt_next_unsub was officially added in mongoose ver 7.3.

Application Setting

config-1

Station Mode

config-2

SSID:SSID of your Wifi router
ESP32 get IP using DHCP.

Station Mode of Static Address

config-3

SSID:SSID of your Wifi router
ESP32 set your specific IP.

Access Point Mode

config-4

SSID:SSID of ESP32
ESP32 have 192.168.4.1.

Using MDNS hostname

You can use the MDNS hostname instead of the IP address.

  • esp-idf V4.3 or earlier
    You will need to manually change the mDNS strict mode according to this instruction.
  • esp-idf V4.4 or later
    If you set CONFIG_MDNS_STRICT_MODE = y in sdkconfig.default, the firmware will be built with MDNS_STRICT_MODE = 1.

mdns-1

mdns-2

You can change MDNS hostname using menuconfig.

config-5

Start Built-In MQTT Subscriber

config-6

Start Built-In MQTT Publisher

config-7

Limitations

  • will topics
    will qos and will retain are ignored.

  • Unsupported MQTT request
    Do not respond to these MQTT requests:
    PUBREC
    PUBREL
    PUBCOMP

Subscribe using mosquitto-clients

$ sudo apt install mosquitto-clients moreutils
$ chmod 777 ./mqtt_sub.sh
$ ./mqtt_sub.sh
21/03/06 18:14:19 esp32 TickCount=110964
21/03/06 18:14:20 esp32 TickCount=111065
21/03/06 18:14:21 esp32 TickCount=111166
21/03/06 18:14:22 esp32 TickCount=111267
21/03/06 18:14:23 esp32 TickCount=111368

Publish using mosquitto-clients

$ sudo apt install mosquitto-clients moreutils
$ chmod 777 ./mqtt_sub.sh
$ ./mqtt_pub.sh

Notify topic of will using mosquitto-clients

  • In Terminal #1, do the following:
$ mosquitto_sub -v -h esp32-broker.local -p 1883  -t "topic/#" --will-topic "topic/will" --will-payload "GOODBYE"
  • Open new terminal. In Terminal #2, do the following:
$ mosquitto_sub -v -h esp32-broker.local -p 1883  -t "topic/#"

  • Press Control+C in Terminal #1:

  • The following is displayed in Terminal #2:

topic/will GOODBYE

Unsubscribe using python and paho

$ pip install paho
$ python unsub_example.py

Connected with result code 0
subscribe hoge

Received message 'b'test'' on topic 'hoge/1' with QoS 1
unsubscribe hoge, subscribe fuga

Received message 'b'test'' on topic 'fuga/1' with QoS 1
unsubscribe fuga, subscribe hoge

First, it subscribes to the topic [hoge/#].
When it receives the topic [hoge/1], it unsubscribes [hoge/#] and subscribes to [fuga/#].
When it receives the topic [fuga/1], it unsubscribes [fuga/#] and subscribes to [hoge/#] again.

Screen Shot

The message flows like this:
PUBLISH->BROKER->SUBSCRIBE
ScreenShot