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How to connect, how to control 8888-Display by MQTT/WiFi
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Most of the Home Assistant hubs are based on this standard, so 8888-Display can be very convenient for showing messages and numbers (and in large!) inside any automation or domotics.
Quickly summarizing, 8888-Display can be controlled via:
WiFi and MQTT connection
Before proceeding further, we remind you that through the WiFi connection you can also
control 8888 Display in HTTP which is a simpler system (it does not require a Broker such as MQTT, just write a Command in the form of a URL in the bar in Safari, Firefox, Chrome etc.).
In Settings and MQTT you will insert:
- the IP or name of the server where the MQTT Broker runs (if left blank,
8888-Display will not use MQTT)
- possibly username and password of the Broker, if needed
8888-Display shows besides the MQTT entry the name of the default topics used for the publication/out and the topic where to receive commands; you can specify a prefix here if you need it (some free brokers require your topics to start with for example
yourusername/feeds/ or something like that), otherwise the "prefix" boxes must be left blank.
Then click Save and
8888-Display will connect, and after a few seconds it will start working in MQTT as well. If the connection is OK it will write OK after the word MQTT; and immediately on the same page it shows the names of the Topics to use to control
8888-Display and to receive 8888-Display messages.
For safety we suggest using a Broker installed on your device (PC or other; you can download and install and run a Broker program such as Mosquitto even on a simple Windows PC; or you can use the
ControlHUB internal broker); depending on the application you may also o use external clouds or external free brokers.
Response / Publication Topic
When it responds to commands, or when it means something, 8888-Display publishes a message on the topic d8-o-name (where Name is the name given to the device a little further down in the Settings).
You need to listen to this Topic to be able to read what 8888-Display says.
The response / payload is a text, eg. date and time after the Command STATE was given; the other commands generate the resend of the command as a response.
Upon power-up, as soon as it is connected to MQTT, 8888-Display issues as if it were responding to STATE.
Topic of Command / Listening
8888-Display always listens on topic d8-c-name (where Name is the name assigned to the device a little further down in the Settings). To command it, the hub, the Assistant or anyone using software or libraries for sending MQTT messages, must publish a message / payload among these on the Command Topic:
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{"Show":"hello guys!"}
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Shows the string bellahello guys!on the display, fissa oppure facendo automaticamente uno scrolling continuativo se la lunghezza della stringa è maggiore dei caratteri disponibili sul display.
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{"One":"hello world!"}
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Visualizza sul display la stringa hello world!, on the display, facendo scrolling per una volta sola; poi ritorna a cosa mostrava in precedenza
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{"SetTime":"1230"}
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passa in modalità orologio e parte dalle 12.30 (NOTA da scrivere senza punto)
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TIME oppure {"TIME"}
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passa in modalità orologio e mostra sullo schermo l'ora corrente (ricordiamo che nelle impostazioni si può settare di modo che si sincronizzi con un pool di orologi atomici via Internet)
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{"Brightness":100}
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setta la luminosità a 100 (valori disponibili in genere da 1 a 100)
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{"Speed":20}
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setta la velocità dello scrolling in centesimi di secondo
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STATE oppure {"STATE"}
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restituisce data e ora
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Come noto, per MQTT è necessario un sistema locale o remoto (accessibile via Internet) che faccia il
Broker; per esempio
ControlHUB.
Se stai facendo un'automation con 8888-Display e WiFi, se vuoi
puoi semplificare, ed evitare questa necessità utilizzando anziché MQTT dei semplici comandi HTTP / Web tramite il collegamento WiFi, magari fissando dentro alle opzioni di configuration del tuo router l'IP di 8888-Display (tipicamente si fa in un menù tipo DHCP utilities; supponiamo sia 192.168.1.4); oppure usando il WiFi interno di 8888-Display senza necessitare di Internet o di un Broker (
manuale collegamento e comandi WiFi/HTTP per 8888-Display...).
Here are the quick manuals for some other products:
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