Internte of Things Open Day

In this lab, we will learn how to control the lab lighting using a computer. This should reveal some of the amazing possibilities of the IoT, as well as some of the potential for misuse if security is not handled correctly. We will learn about this, while playing with a little bash scripting on Ubuntu Linux.

Turning the lights on and off

The lab you are sitting in contains network accessable lighting. Look directly above you and make a note of the FIXTURE NUMBER noted one your light. Note the command provided below.

curl -i -X PUT -H 'Content-Type: application/json' -d '{"target": "fixture","num": FIXTURENUMBER,"intensity": 255,"red": 255,"green": 0,"blue": 0,"temperature": 255,"fade": 1.0,"path": "Default"}' http://10.50.41.230/api/override

Copy the line above into a text editor, and then change the FIXTURENUMBER to the light found on your computer overhead. Once you have edited this in a text editor, Open a terminal, the black box on the side of your Desktop. Copy and paste the edited command from your text editor into the terminal. Did your light turn on? What was the colour? Change the values to make the light your favourite colour.

How do you think you could switch the light off? Play with the parameters and ask for help if you need some guidance.

Some Basic Bash Programming

This section will introduce you to looping in bash. Open a new text editor window and paste in the following code.

#!/bin/bash

for i in {1..5}
do
  echo "Hello World!"
  sleep 1s
done

Save the file as:

lighting.sh 

Then ensure that the file has execute permissions by typing the following into your terminal window:

chmod 777 lighting.sh

Then run the program in the terminal with the following command:

./lighting.sh

Press Ctrl+C to stop the program when you have seen enough hello worlds.

Tasks

• Can you modify the program to print ten Hello worlds?
• Can you modify the program to see if you can turn the light on and off every second?
• After you have done this, can you modify the program to change the color every second?