IoT Parking Lot Demo on Toradex Modules

1

IoT Parking Lot Demo on Toradex Modules

2

• Introduction
• In this blog post, I am going to talk about our
  IoT parking lot demo and the technology behind
  it. I will try to explain how to use Azure IoT
  Hub to send messages between Azure services and
  devices to achieve

CHAIRMAN
the same level of communication we had in our
demo. I will also quickly try to explain all the
different modules we used in our demo, but my
samples will focus on Azure IoT Hub and how to
easily send and receive messages. If you are
interested in knowing more about Azure IoT Hub,
you can check the details here.
3

• In our demo, we have used multiple devices,
  namely
• Parking Lot 1 (called Stretnor in our demo)
• Parking Lot 2 (called Theater Parkhouse in our
  demo)
• Public Display (Parking Lot independent device)
• Every parking lot consists of more than one of
  the following devices
• Gate Controller (Colibri T30 running Win10 IoT)
• Parking Controller (Colibri VF50 running Windows
  Embedded Compact 2013)
• Payment Terminal (Apalis iMX6 running Linux and
  Qt)
• Public Display (Colibri iMX6 running Windows
  Embedded Compact 2013)

4
(No Transcript)
5

• As you can see in the above image, all the
  communication messages go through the Azure IoT
  Hub to the application service that processes
  these messages. You can also see that we have a
  web page and database running in Azure but this
  blog post focuses only on the part about Azure
  IoT Hub.
• Message flow in IoT Parking demo
• There are two basic events that trigger the flow
  of information between devices and IoT Hub.
• The first event is when a car arrives at the gate
  (refer the diagram below)

CHAIRMAN
6

CHAIRMAN
7

When a car arrives to the gate, the gate
controller will scan the license plate and send a
message to IoT Hub (1). After the application
service verifies the data, it will send the
message back to Gate Controller to open the gate
(2). At the same time, a message is sent to the
Parking Controller with the number of assigned
parking spaces (3). The Parking Controller will
start blinking the Red light indicating that the
parking space is going to be occupied soon. The
message is sent also to the Payment Terminal.
This message includes the license plate number
and time of arrival (4). At the same time, the
Public Display receives the information about all
the parking spaces in the area (5). When the car
is parked at the parking space, the Parking
Controller stops blinking the Red light and sends
a message to the IoT Hub indicating that car is
parked (6). At the same time, the Gate Controller
is informed to close the gate (7).
CHAIRMAN
8

CHAIRMAN
9

• When a car leaves the parking lot, the driver has
  to pay the parking charges first. On the Payment
  Terminal, a person can select the appropriate
  license plate of their car and select pay. A
  message is then sent to the IoT Hub initiating a
  request of payment (1). Application service
  calculates the price and sends it back to the
  Payment Terminal (2). When the Payment Terminal
  receives the payment credit, it sends the
  information to the IoT Hub that the payment was
  successful (3). Application service will than
  send a message to the Parking Controller that the
  car is about to be removed from the parking lot
  (4). The Parking Controller starts blinking the
  Green light. After the car is removed from the
  parking space, a message is sent to the IoT Hub
  indicating the removal of car (5). The Parking
  Controller also opens the gate to exit. After a
  timeout value, the gate is closed again and a
  message is sent to the IoT Hub that the parking
  space is now free. After this, the Public Display
  again shows the updated information on all the
  parking lots (6).

CHAIRMAN
10

Sample application In the following sample
application, I will try and show to you how to
communicate with the Azure IoT Hub easily. To
understand this sample you need a basic
understanding of C. If you want to build the
application, you will need Visual Studio
2015. To run the example, you will also need an
Azure account. You will need to create a free
Azure IoT Hub and create a device on your Azure
IoT Hub. You can use the device explorer to do
this. Device explorer documentation can be found
here. Here I am going to show you a small example
of a server-side application that takes messages
from the IoT Hub and processes them. This code is
really simple and is not meant for the production
environment.
CHAIRMAN
11
It is only to show you how easy it is to
communicate with the Azure IoT Hub. In this
example, we only receive the message from the
device and send new messages back to the same
device. You will have to modify the server-side
code with your connection string.
As you can see in my sample, I have only called
the method connect of the class TDXServerEmulator
12
This will take care of receiving and responding
to messages. To use the clients, you need to
replace the URL to Azure IoT Hub with your URL.
Device.cs.
CHAIRMAN
Inside your client you need to create a new
Device object and register the OnMessageReceived
event. This will allow you to get all the
messages sent from the Azure IoT Hub to your
device.
13

After this, you will be able to run the demo
project. After youve executed the project, two
console applications will appear. You have to
wait for the server application to be ready for
connection
CHAIRMAN
14

After the server is ready, you can select Send
Hi from the client application.
CHAIRMAN
In the image above, you can see the client
sending Hi. After the server received the
message from client, it responds with the
following message, Hi from IoT Hub.
15

As you can see in my sample, it is really easy to
communicate with the Azure IoT Hub and send
simple messages. For more complex applications,
there are many things that can be improved but
that also makes the sample application more
complex. With this sample and explanation, you
should be able to develop simple applications
using Azure IoT Hub. Also all Toradex modules
support Azure IoT Hub. You can read more about
the type of support offered by the Toradex
modules here. You can also download SDKs for
WinCE and Linux.
CHAIRMAN
16
Thank you!