ST0324 Internet of Things CA2 Step-by-step Tutorial

SCHOOL OF COMPUTING (SOC)

ST 0324 Internet of Things (IOT)

• Section 1 Overview of Smart Home
• Section 2 Hardware required
• Section 3 Hardware Diagram
• Section 4 Create a “Thing”
• Section 5 DynamoDB Setup
• Section 6 Reading RFID/NFC tags setup
• Section 7 Program setup
• Section 8 Expected outcome

Smart Home enables users to remotely monitor and manage applicances such as lighting, humidity and door access. There are several features to our project. Firstly, users will be able to view the humidity of their house via a web application. Secondly, users will be able to control their lightings remotely by clicking the on and off button on the web application. Aside from that, users will also be able to view how bright is their home is. Last but not least, we also have an RFID feature that allows user to access their door with a access card instead of the traditional way of using keys. The door will be open for 5 seconds and after that the door will be locked automatically. We also made a function that allows users to view real time values of their humidity, light and temperture level.

Final Set-up

Overview of SmartHome internally

Our application has several functions that requires specific hardware and below is the list of hardware needed and explains the details about each hardware.

2 Light Dependant Resistor (LDR)

An LDR is a component that has a (variable) resistance that changes with the light intensity that falls upon it. This allows them to be used to sense light values. We will use this hardware to sense the light values of the surroundings.

2 Analog to Digital converters (MCP3008)

The Raspberry Pi has no built in analogue inputs which means it makes it difficult to use many of the available sensors, with this converter it helps to convert analog to digital signals for the RPI.

4 LED (Any colour)

The LED lights indicates whether the lights are on or off. Insert the LED with the anode (long leg) towards the board.

8 Resistors (4 x 330 Ω Resistors, 4 x 10K Ω Resistor)

Resistors help with the current flow and to prevent the Raspberry Pi from being damaged.

2 DHT Sensors

DHT sensors are used to measure temperature and relative humidity. These sensors contain a chip that does analog to digital conversion and spit out a digital signal with the temperature and humidity. We used to to monitor the temperature and humidity.

2 RFID / NFC MFRC522 Card Reader Module

This module can read/write to tags and cards and also "act" like a NFC tag. The RFID Reader Module can be used in a wide variety of hobbyist and commercial applications, including access control. We use the card to access to the main door by tapping on the NFC card reader.

1 RPI Camera Module

We use the RPI camera module to take pictures and it will upload to AWS cloud service (S3 bucket). The camera has a function to detect general object such as humans, bottle etc.

In this section, The Fritzing iagram shows all the necessary components described in Section 2.

Firstly, navigate to IoT Core within the AWS website by clicking on services, then IoT Core.

Under manage, select things and choose register a thing.

Choose Create a single thing.

Give a name for your thing, for example, SmartHome. Ignore the rest of the fields. Click next.

Select create certificate and you will be redirected to the following page. Download all four files. As for the root CA, download the Amazon Root CA3

Once done, rename the four files accordingly.

Move the four files into a directory in the raspberry pi (RPI).

Click activate.

Click register thing. Policy will be created later.

Go to policies under the secure section. Select create a policy.

Give a name for your policy, for example, SmartHomePolicy and enter the following under Add statements

Go to certificates under secure section. Select the certificate you created previously, and click attach policy. Attach the policy you created previously.

Run the following command on your Raspberry Pi to install the AWS Command-line client on your Raspberry Pi

sudo pip install awscli --upgrade --user

Edit the .profile to include the path of the AWS client

sudo nano ~/.profile

Add in the following code after the last line and save the file

export PATH=~/.local/bin:$PATH

Type the following command at the command-line prompt to make the new settings take effect immediately

source ~/.profile

Type the following command to install the AWS Command-Line Interface Client on your Raspberry Pi

sudo pip install awscli

Copy down your AWS educate’s Access Key ID and Secret Access Key ID.

First, Go to DynamoDB within the AWS website by clicking on services, then DynamoDB. Click create table.

Enter the table name and the primary key, then click create.

Next, go back to IoT Core within the AWS website by clicking on services, then IoT Core. Click Act, then create button at the top right corner.

Create the rule with the name “iotdata”.

Under Set one or more actions section, choose add action, select “split message into multiple columns of a database table”. Select configure action. Under table name, select the “iotdata” table. Under IAM role name, select the role you created previously, “iotlab11role”. For mine i'm using back an old role. Click add action, then create rule.

Now that we had created the rules, we can add items to the data table. Navigate to the test section of IoT Core in AWS.

Scroll down to Publish. Enter the topic “sensors/light”. Enter the following in the text field below:

{
“deviceid”: "HomeMonitor",
“Light”: “”
}

The data is in the iot table.

If your raspberry pi is new, you will need to configure it with the MFRC522 libraries, you can follow the following instructions to set it up.

Run raspi-config, choose menu item “5 Interfacing Options” and enable SPI.

sudo rasp-config

Modify the /boot/config.txt to enable SPI

sudo nano /boot/config.txt

Ensure these lines are included in config.txt

device_tree_param=spi=on
dtoverlay=spi-bcm2835

<< Install Python-dev>>

Install the Python development libraries

sudo apt-get install python-dev

<< Install SPI-Py Library >>

Set up the SPI Python libraries

git clone https://github.com/lthiery/SPI-Py.git
cd /home/pi/SPI-Py
sudo python setup.py install

<< Install RFID library >>

Clone the MFRC522-python library and copy out the required files to your project directory

git clone https://github.com/rasplay/MFRC522-python.git
cd MFRC52 2 - python

Edit the MFRC522.py file that you just cloned from GitHub.

sudo nano ~/iotca2/MFRC522.py

To ensure that the guide is not to wordy, we won't be explain all the codes that we did for the project. Instead we will zip all the files needed for this project.

Install Mosquitto using the command below.

sudo apt-get install mosquitto mosquitto-clients

To run Node Red using the command below.

Node-red start

Install the AWS Python library

sudo pip install --upgrade --force-reinstall pip==9.0.3
sudo pip install AWSIoTPythonSDK --upgrade --disable-pip-version-check
sudo pip install --upgrade pip

To view our project video please visit this link https://youtu.be/43--SwQEI5I

LED Light Lights can be turn on and off by using the web interface. Note that toilet light will only be turned on when the envirionment is dark.

Humidity DHT sensor will sense the humidity and temperture level will be reflected on the web and data will be stored in DynamoDB

Camera Camera will be able to take pictures and detect if its an object or human and results will be displayed as well.

RFID User can scan the card to unlock the door

Website Website allows user to view real time values and turning off and on their lights. Apart from that, they will also be able to control the camera function and view the door status.

-- End of CA2 Step-by-step tutorial --