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This library provides a client for doing simple publish/subscribe messaging with a server that supports MQTT.
The library comes with a number of example sketches. See File > Examples > PubSubClient within the Arduino application.
Full API documentation is available here: http://pubsubclient.knolleary.net
- It can only publish QoS 0 messages. It can subscribe at QoS 0 or QoS 1.
- The maximum message size, including header, is 128 bytes by default. This
is configurable via
- The keepalive interval is set to 15 seconds by default. This is configurable
- The client uses MQTT 3.1.1 by default. It can be changed to use MQTT 3.1 by
changing value of
The library uses the Arduino Ethernet Client api for interacting with the underlying network hardware. This means it Just Works with a growing number of boards and shields, including:
- Arduino Ethernet
- Arduino Ethernet Shield
- Arduino YUN – use the included
YunClientin place of
EthernetClient, and be sure to do a
- Arduino WiFi Shield - if you want to send packets > 90 bytes with this shield,
- Sparkfun WiFly Shield – library
- TI CC3000 WiFi - library
- Intel Galileo/Edison
The library cannot currently be used with hardware based on the ENC28J60 chip – such as the Nanode or the Nuelectronics Ethernet Shield. For those, there is an alternative library available.
This code is released under the MIT License.