Japanese Nostalgic Message Board (MQTTwrapper Class Demo)

(No library is wrapped...)

Go back to example list / Go to the repository of this example on GitHub

HOST (Where is the broker):

SEND (Behave as a publisher):

RECV (Behave as a subscriber):

Message Board (Pick up from the subscriber):

This HTML program (re)writes the message into the message board after the above subscriber has received the following command.

write xy msg

x

Column Code: For instance, "a" means the date column because the column is at the leftmost and has the code "a." You have to specify with a row number in practice, like that "a1."

y

Row Number: For instance, "1" means the head line of the table because the head line is numbered one. You have to specify with a column code in practice, like that "a1."

msg

Message Text: You can contain space characters in the body of the text. And if you omit the whole part of the message text, the content in the corresponding cell will be erased.

README (What is this?):

This is a control panel to try to use the MQTTwrapper class. This library makes your web browser an MQTT-over-WebSocket speaker. And then the protocol is very helpful to send/receive text data (also byte stream) from/to the UNIX stdin/stdout.

Only one simple application is required to connect to the stdin/stdout. That is "Mosquitto."

Try to use me by the following steps.

How to Use Me:

0-1) [PREP.] Install Mosquitto

The installation instructions are on this page.

0-2) [PREP.] Write the configuration for Mosquitto

Copy and save the following text as the file "mosquitto.local.conf" in your favor directory.
allow_anonymous true #=== Plain MQTT listener 1883 protocol mqtt #=== Plain MQTT over WebSocket listener 8000 protocol websockets #=== Secure MQTT over WebSocket (TLS) listener 8884 protocol websockets certfile /PATH/TO/YOUR/certfile.pem keyfile /PATH/TO/YOUR/keyfile.pem cafile /PATH/TO/YOUR/cafile.pem

1) Start an MQTT broker

Type the following command on your UNIX terminal.
$ mosquitto -c mosquitto.local.conf

2) Connect me to the MQTT broker

In the "HOST" section, fill in the URL form (Specify "ws://localhost:8000/" to use the above MQTT broker, of course, it's OK to use another broker.) and push the "Connect" button. Then, wait for the button name to be "CONNECTED."

3) Start subscribing

Decide on the topic name in the "RECV" secion and type it into the "topicname" field. Then, push the "Start" button in the same section.

4) Publish a message rewriting command

Publish a message rewriting command on your UNIX terminal with the same topic name and to the same MQTT broker as what you specified in this HTML, like this:
$ echo "write c3 I'll be back soon." | mosquitto_pub -l -h HOSTNAME -t "TOPICNAME"
Then you can see the message you published on the message board.

Or you can also publish the same rewriting command from the publisher in the "SEND" section on this HTML.