View source for Using MQTT to send data to datonis

<h1 id="mqttclientsenddatatodatonis">MQTT client send data to datonis.</h1>

<p>MQTT protocol can be used to send metric data to datonis. MQTT is a bidirectinal pub/sub protocol. We publish event data to datonis in specified format and get acknowledge message on subscribing to another topic.</p>

<h2>MQTT Connection Properties</h2>

<ul>
<li>Hostname: telemetry.datonis.io</li>

<li>Port: 1883</li>

<li>Username: access_key</li>

<li>Password: it is HMAC (SHA256) of access key using secret key.  Use this link for getting password - https://www.freeformatter.com/hmac-generator.html , put access key in string input box, secret key in secret key box and select SHA256 as algorithm. then use computed HMAC as a Password </li>

<li>ClientID: unique 22 chars string. Same string is used in mqtt topics while publishing and subscribing.</li>
</ul>

<h2 id="datapacketformat">Data Packet format</h2>

<pre>{ "data": { "voltage": 233.43, "current": 10 },"thing_key": "178b43t47a","access_key": "87a3f5b3317d9afdtbcbeba6527b4fd759923t5e","timestamp": 1531180873940}
</pre>

<p><strong>Timestamp is epoch timestamp in milliseconds.</strong>
<strong>voltage and current are properties present in thing template in which thing key 178b43t47 belongs to.</strong></p>

<h2 id="mqtttopics">MQTT Topics</h2>

<ul>
<li><code>Altizon/Datonis/&lt;clientid&gt;/event</code> for publishing messages to datonis. Use above mentioned data format while publishing messages.</li>

<li><code>Altizon/Datonis/&lt;clientid&gt;/httpAck</code> this topic publishes acknowledgement of all received messages. This will also display if it gets any error while sending data to datonis. Subscribe to this topic for acknowledgements.</li>
</ul>

<h1 id="examples">Example</h1>

<p>Examples using https://chrome.google.com/webstore/detail/mqttlens/hemojaaeigabkbcookmlgmdigohjobjm this tool.</p>

<p>topics: </p>

<ul>
<li>Altizon/Datonis/mqtt_87a3f5b3317d9afd/event</li>

<li>Altizon/Datonis/mqtt_87a3f5b3317d9afd/httpAck</li>
</ul>

<p>Connection Properties:</p>

<table>
<tr><td>Username:</td><td> 87a3f5b3317d9afdtbcbeba6527b4fd759923t5e</td></tr>
<tr><td>Password:</td><td> c725bdea20e523cdbfc7f100722fc9f0384c37e2c1cc5176e8631da8aa65c502</td></tr>
<tr><td>ClientID:</td><td> mqtt_87a3f5b3317d9afd</td></tr>
</table>

Connection Configuration as below

[[File:MQTT connection properties.png|1056x1056px]]


Publish & Subscribe can be done as below

[[File:Publish & Subscribe topic.png|1056x1056px]]

<h2>Password Generation</h2>
Password can be generated from access_key and secret_key as below.

[[File:MQTT_password_computation.png]]