Our range of LED dot matrix displays are used for all sorts purposes, and one new example we'd like to share is by Toby Robb who uses the DMD as an MQTT message client. In other words, the DMD can display text messages from an MQTT server via an Ethernet-enabled Arduino-compatible board or Arduino with an Ethernet shield.
For the curious, MQTT stands for...
... MQ Telemetry Transport. It is a publish/subscribe, extremely simple and lightweight messaging protocol, designed for constrained devices and low-bandwidth, high-latency or unreliable networks. The design principles are to minimise network bandwidth and device resource requirements whilst also attempting to ensure reliability and some degree of assurance of delivery. These principles also turn out to make the protocol ideal of the emerging “machine-to-machine” (M2M) or “Internet of Things” world of connected devices, and for mobile applications where bandwidth and battery power are at a premium.
And with the code and sketch provided by Toby, the DMD works using open-source software as a display unit in the following example video:
As used in the project mentioned above, check out our Freetronics Dot Matrix Displays. They're simple to use, yet very bright for indoor and outdoor situations. Available in various colours, the 32 x 16 LED matrix can display text and graphics quite easily - and can be daisy-chained together for extended displays. For more information, see our range of Dot Matrix Displays here.