(r8) MQTTAndCayenne < AFNOG

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%SLIDESHOWSTART%
---+ Setting up an !IoT
<h1 align="center">Session 3: MQTT and Cayenne</h1> <h1 align="center">Uli Raich<br /><br />Formally CERN, Geneva, Switzerland</h1>

---++ 
---+ The Network Layers

The !WeMos D1 mini has a built-in !WiFi interface<br /><br />In order to communicate with other !IoT nodes we must therefore

connect to the !WiFi network first<br /><br />On top of !WiFi we will run a TCP session<br /><br />On top of TCP we will run the MQTT protocol<br /><br />On top of MQTT we have dedicated topics and payloads imposed by Cayenne

---++ 
---+ Accessing the !WiFi network

<img alt="wifiDemoCode.png" height="349" src="%ATTACHURL%/wifiDemoCode.png" title="wifiDemoCode.png" width="547" />
---++ 
---+ Accessing the !WiFi network from Micropython

<img alt="wifiConnect.png" height="803" src="%ATTACHURL%/wifiConnect.png" title="wifiConnect.png" width="1056" />

---++ 
---+ MQTT

MQTT (Message Queuing Telemetry Transport: a publish-subscribe based <br /><br />message protocol running of top of TCP.<br /><br />A processor can subscribe to messages of a certain “topic” and/or it can push its<br /><br />results on a certain topic

<img alt="mqttPostOfffice.png" height="267" src="%ATTACHURL%/mqttPostOfffice.png" title="mqttPostOfffice.png" width="722" />

---++ 
---+ MQTT Demo

<img alt="mqttDemo.png" src="%ATTACHURL%/mqttDemo.png" title="mqttDemo.png" />

---++ 
---+ The Micropython library

<img alt="micropython-lib.png" height="464" src="%ATTACHURL%/micropython-lib.png" title="micropython-lib.png" width="654" />

---++ 
---+ A MQTT example using umqtt.simple

<img alt="umqttDemo.png" height="564" src="%ATTACHURL%/umqttDemo.png" title="umqttDemo.png" width="535" />

---++ 
---+ Sending dummy temperature data

<img alt="mqttDummySensorDemo.png" height="582" src="%ATTACHURL%/mqttDummySensorDemo.png" title="mqttDummySensorDemo.png" width="535" />

---++ 
---+ Receiving commands

Receiving commands is a bit more tricky! We must:<br /><br />
   * Write a callback function and register it with the MQTT client
   * This function takes 2 arguments:
   * The topic
   * The payload
   * Subscribe to the topic
   * Wait forever. The callback function will be executed when a message with the <br />topic we subscribed to, will arrive
---++ 
---+ Subscribe a callback

<img alt="subscribeDemo.png" height="650" src="%ATTACHURL%/subscribeDemo.png" title="subscribeDemo.png" width="539" />

---++ 
---+ Callback result

<img alt="callbackResult.png" src="%ATTACHURL%/callbackResult.png" title="callbackResult.png" />

---++ 
---+ Controlling a LED

In order to control a LED through MQTT we now simply interpret the payload:
   * Message “LED on”
   * Message “LED off”

---++ 
---+ Changed Callback

<img alt="changedCallback.png" height="148" src="%ATTACHURL%/changedCallback.png" title="changedCallback.png" width="369" />

---++ 
---+ Missing functions in IoT
   * MQTT broker should be globally reachable
   * GUI to easily visualize sensor measurements
   * GUI elements to easily control actuators
   * GUI should be accessible through a WEB interface
   * GUI should be accessible through smart phone app
This is what Cayenne supplies

---++ 
---+ Cayenne functionality
   * MQTT broker is accessible at mqtt.mydevices.com<br /><br />
   * Supplies GUI
<img alt="cayenneFunctionality.png" src="%ATTACHURL%/cayenneFunctionality.png" title="cayenneFunctionality.png" />

---++ 
---+ Signing up for Cayenne

Sign up at<br /> https://mydevices.com/cayenne/signup

<img alt="cayenneSignup.png" height="955" src="%ATTACHURL%/cayenneSignup.png" title="cayenneSignup.png" width="904" />

---++ 
---+ Cayenne Start

<img alt="cayenneStart.png" src="%ATTACHURL%/cayenneStart.png" title="cayenneStart.png" />

---++ 
---+ Cayenne Doc

You find the documentation at

https://mydevices.com/cayenne/docs/intro

Contains short introductory video clips, information of Cayenne on Raspberry Pi and Arduino but also how to use Cayenne on any device.

Pointers to the Cayenne MQTT Libraries and their API

<img alt="cayenneDoc.png" src="%ATTACHURL%/cayenneDoc.png" title="cayenneDoc.png" />

---++ 
---+ Installing Cayenne on the Raspberry PI

<img alt="cayenneRPI.png" height="791" src="%ATTACHURL%/cayenneRPI.png" title="cayenneRPI.png" width="1244" />

---++ 
---+ Installing Cayenne on the Raspberry Pi manually

<img alt="cayenne_RPI_ManualInstallation.png" height="791" src="%ATTACHURL%/cayenne_RPI_ManualInstallation.png" title="cayenne_RPI_ManualInstallation.png" width="1244" />

---++ 
---+ Register your Controller Single Board Computers

<img alt="cayenneRegisterRPI.png" height="907" src="%ATTACHURL%/cayenneRegisterRPI.png" title="cayenneRegisterRPI.png" width="1146" />

---++ 
---+ Run Cayenne on the Arduino

<img alt="cayenneArduinoInstall.png" height="791" src="%ATTACHURL%/cayenneArduinoInstall.png" title="cayenneArduinoInstall.png" width="1244" />

---++ 
---+ Basic Arduino Sketch for the Arduino

<img alt="cayenneArduinoSketch.png" src="%ATTACHURL%/cayenneArduinoSketch.png" title="cayenneArduinoSketch.png" />

---++ 
---+ Cayenne Credentials

<img alt="cayenneCredentials.png" height="835" src="%ATTACHURL%/cayenneCredentials.png" title="cayenneCredentials.png" width="1034" />

---++ 
---+ Cayenne network layers

<img alt="cayenneNetLayers.png" height="366" src="%ATTACHURL%/cayenneNetLayers.png" title="cayenneNetLayers.png" width="1415" />

The Cayenne credentials are integrated into the MQTT topic string<br /><br />Value and units are integrated into the payload string

---++ 
---+ Cayenne and Python

This falls under “bring your own thing” !<br /><br />Having a look at the Arduino sketch you can see that it uses the<br /><br />Arduino Cayenne C++ library.<br /><br />Cayenne MQTT libraries are available in<br /><br />
   * C, C++
   * Python
   * Java
and probably a few other languages

---++ 
---+ Cayenne and Micropython

The Python Cayenne Client library depends on the Eclipse Paho MQTT library<br /><br />Micropython uses its own, stripped down “umqtt” (micro mqtt) library

such that the standard Cayenne Client does not work on Micropython<br /><br />but …<br /><br />The Python Cayenne Client is Open Source and can be adapted to umqtt, which is what I did for you.

The adapted Client library uses the same API as the original one,

which means that the example programs work unchanged.

---++ 
---+ The Cayenne Client

When creating a Cayenne Client Class it <br /><br />
   * Initializes its internal variables
   * Checks if the OLED display is connected and if yes, initializes it
   * The Cayenne Client has has a begin method which
   * Connects to !WiFi
   * Connects to the Cayenne MQTT broker at mqtt.mydevices.com
   * Subscribes to commands send by Cayenne
   * Displays its internal state on the OLED display
---++ 
---+ The code to connect to Cayenne

<img alt="cayenneConnectCode.png" src="%ATTACHURL%/cayenneConnectCode.png" title="cayenneConnectCode.png" />

---++
---+ Connecting to Cayenne

<img alt="cayenneConnect.png" height="870" src="%ATTACHURL%/cayenneConnect.png" title="cayenneConnect.png" width="806" />

---++
---+ The empty Cayenne dashboard

<img alt="cayenneEmptyDashboard.png" src="%ATTACHURL%/cayenneEmptyDashboard.png" title="cayenneEmptyDashboard.png" />

%SLIDESHOWEND%

-- %USERSIG{UliRaich - 2019-05-14}%

---++ Comments

%COMMENT%

Attachments

Topic attachments
I	Attachment	History	Action	Size	Date	Who
odp	afnog19-ws-session3.odp	r1	manage	5245.0 K	2019-05-15 - 19:13	UliRaich
png	callbackResult.png	r1	manage	142.7 K	2019-05-22 - 12:31	UliRaich
png	cayenneArduinoInstall.png	r1	manage	128.4 K	2019-05-22 - 16:32	UliRaich
png	cayenneArduinoSketch.png	r1	manage	191.2 K	2019-05-22 - 16:35	UliRaich
png	cayenneConnect.png	r1	manage	137.9 K	2019-05-22 - 16:52	UliRaich
png	cayenneConnectCode.png	r1	manage	56.8 K	2019-05-22 - 16:52	UliRaich
png	cayenneCredentials.png	r1	manage	109.7 K	2019-05-22 - 16:36	UliRaich
png	cayenneDoc.png	r1	manage	158.3 K	2019-05-22 - 16:21	UliRaich
png	cayenneEmptyDashboard.png	r1	manage	150.2 K	2019-05-22 - 16:52	UliRaich
png	cayenneFunctionality.png	r1	manage	135.7 K	2019-05-22 - 16:09	UliRaich
png	cayenneNetLayers.png	r1	manage	34.5 K	2019-05-22 - 16:45	UliRaich
png	cayenneRPI.png	r1	manage	150.8 K	2019-05-22 - 16:24	UliRaich
png	cayenneRegisterRPI.png	r1	manage	148.3 K	2019-05-22 - 16:24	UliRaich
png	cayenneSignup.png	r1	manage	122.2 K	2019-05-22 - 16:15	UliRaich
png	cayenneStart.png	r1	manage	146.3 K	2019-05-22 - 16:15	UliRaich
png	cayenne_RPI_ManualInstallation.png	r1	manage	189.9 K	2019-05-22 - 16:30	UliRaich
png	changedCallback.png	r1	manage	15.3 K	2019-05-22 - 16:06	UliRaich
png	micropython-lib.png	r1	manage	75.2 K	2019-05-14 - 17:31	UliRaich
png	mqttDemo.png	r1	manage	191.3 K	2019-05-14 - 17:23	UliRaich
png	mqttDummySensorDemo.png	r1	manage	74.4 K	2019-05-20 - 18:40	UliRaich
png	mqttExample.png	r2 r1	manage	73.2 K	2019-05-15 - 16:12	UliRaich
png	mqttPostOfffice.png	r1	manage	50.2 K	2019-05-14 - 17:18	UliRaich
png	realData.png	r1	manage	27.7 K	2019-05-15 - 17:12	UliRaich
png	subscribeDemo.png	r1	manage	78.3 K	2019-05-20 - 18:45	UliRaich
png	umqttDemo.png	r2 r1	manage	72.2 K	2019-05-14 - 17:38	UliRaich
png	wifiConnect.png	r1	manage	128.4 K	2019-05-14 - 17:18	UliRaich
png	wifiDemoCode.png	r1	manage	43.8 K	2019-05-15 - 16:14	UliRaich

Topic revision: r8 - 2019-05-22 - UliRaich