Table of Contents
The purpose of this sequence of resources is to allow teachers to complete most of the Stage 3 DT coding learning outcomes in just the single historical context of the electric telegraph and sending a distress signal
The various iterations of SOS KookaBlockly code for these resources, together with a pdf of the resources can be downloaded from within the SOS.kby.zip file in the sidebar to the right.
This plan is targeted at students in years 5&6 (Stage 3) but can be introduced in Stage 3 and as a bridging course between visual and text-based programming languages in Stage 4. This is because KookaBlockly allows students to see the text-based python code behind the blocks.
This resource could probably be implemented over a number of Terms if all the coding activities were implemented successively and coupled with research into the electric telegraph.
Learning Outcomes & Curriculum Mapping
- Learn about the invention, spread and significance of the electric telegraph. [Electric circuits, history of communications and commerce] AC9TD16P01
- Learn about digital systems [integration of peripherals with the Kookaberry] AC9TD16K01
- Observe how data can be represented by off and on states and by numbers and symbols [Morse Code] AC9TI6K04
- Observe how digital systems form networks to transmit data [MorseCode App] AC9TDI6K02
- Write and edit a programme in a visual programming language [KookaBlockly] AC9TDIP05
- Recognise that steps in algorithms need to be accurate and precise [Length of sleep times are critical]
- Learn about, use, and control different output devices [LED and Buzzer] AC9TD16K01
- Learn how to trouble shoot through trial and error whilst programming in real time [Vary sleep times]
- Learn how to use branching statements (if/do) in programmes [If button pressed] AC9DI6P02
- Learn about repeat loops [Repeat a dot or a dash three times for the letters S and O] AC9TDI6P05
- Learn how functions can reduce the number of coding steps [Set up functions for each of S and O] AC9TDI6P05
- Learn how to position and write text on a screen [Vary position and size of font on the Kookaberry’s screen] AC9TDI6P03 AC9TDI6P05
- Learn how to input and change user data in a programme [Pin numbers and sleep duration] AC9TDI6P04
- Save and rename files across multiple locations [Add a .kby suffix]
Before commencing this set of resources, teachers and students should be familiar with the following concepts and technology fundamentals.
- Copying, moving, and pasting files
- Digital Systems: Introduction to digital systems
- Using the Kookaberry: Getting started with the Kookaberry
- Using KookaBlockly: KookaBlockly
In the middle of the 18th Century, Samuel Morse co-invented the electric telegraph and the Morse Code. His code consisted of just two data states – a dot and a dash – to represent the letters of the alphabet; the numbers 0-9; and a few punctuation marks and symbols.
The electric telegraph is basically an electrical circuit between two destinations. The earliest systems consisted of single wires strung on poles.
An electrical voltage was applied to the overhead wire by batteries at a transmitting station, and the circuit was completed by the electric current travelling back to the battery through the earth. A telegraph key was held down briefly to make a short signal, a dot, and slightly longer for a dash.
The electric telegraph spread around the world transforming commerce and influencing society with its instant global news. When Marconi invented long distance radio in 1901, morse code was used to transmit text messages.
The British Empire used telegraph cables, both overland and under the sea, to connect its Colonies together in what was called the All Red Line. The last link was the amazing 3,200km overland telegraph between Port Augusta in South Australia, and Darwin completed in 1902.
After the Titanic sank in 1912, telegraph operators and their radios were required to be on all ships so that they could call for help and transmit their location if they were in distress. Although Samuel’s code is no longer in commercial use, the universal name for his distress signal – SOS – is still well known today.
FunFact: SOS does not mean Save Our Souls or any other message. It is just a very recognisable and easy to remember sequence of morse code letters – dot, dot, dot, dash, dash, dash, dot, dot, dot.
[Question: What do think is the reason why the letter E is just a single dot in Morse code?]
Kookaberry & USB lead
Connect the Kookaberry to your PC or Mac, and plug the LED Module into socket P1 on your Kookaberry
The Morse Code Distress Signal
In Morse Code. “S” is three dots and “O” is three dashes. The timing is as follows. Pick a duration time of 0.2 secs for a dot
- a dash is 3x the duration of a dot
- the silence between dots and dashes is the same as a dot.
- the silence between letters is equivalent to 3x dots or a dash
- the silence between words is a minimum of 7x dots
SOS Resource 1: Blinking a LED
Open KookaBlockly; open the Control menu; and drag the “every loop” Control block onto the canvas. Then go the Pins menu and drag the “turn pin….on” into the control loop. The default Pin number is P1, but this can be set to other Pins from the drop down menu within the block.
Now go back to the Control menu and drag the “sleep for ….seconds” into the control loop. Set the sleep time for the amount of delay required (2 secs in the example shown)
Now turn P1 off for the required number of seconds by dragging the blocks into the control loop.
The KookaBlockly code in the downloaded zip folder for this resource is called SOSblink.kby.py. Run the programme.
SOS Resource 2: Simple code repetition
To send the SOS message, take the blink code created SOS Lesson Plan 1, and create a dot and dash by varying the sleep interval between Pin ON and Pin OFF. The letters S and O are created by repeating the code for dots and dashes, taking care to use the correct spacing (sleep interval) between symbols (a dot or a dash); letters (S or O) and words (SOS). The resulting code will look like this in KookaBlockly.
Run the programme and see the distress signal sent once only.
Adding a control loop will repeat the message over and over.
The KokkaBlockly code in the downloaded zip file in the Sidebar, is called SOSsimple.kby. It shows the control loop programme blocks greyed out. This means that the instructions will be ignored when the programme is Run. Only one SOS message will therefore be sent.
The blocks within the loop can be enabled or disabled by right clicking on the control block to reveal the block’s dropdown menu. The same menu can be used to duplicate a block, or set of blocks.]
SOS Lesson Plan 3: Using the repeat loop
Computers are great at repeating instructions, or sets of instructions, at blinding speed. Programmers take advantage of this by setting up one instruction and then telling the computer how many times to repeat it. These instructions are called Loops and can be found in the Loops menu.
Drag the repeat 10 times loop onto the canvas and place the Dot sequence of steps inside it. Change the repeat times to 3. Repeat for the Dash sequence.
Now create just one dot and one dash sequence, and drag them into the repeat loops as shown below.
The KookaBlockly code for this resource in the downloaded zip folder is called SOSrepeat.kby.py. Run the programme.
…..Now hear it
Press the reset button on the back of the Kookaberry and swap the LED module for a Buzzer Module to hear the distress signal the same way as radio operators did in the past. If you have a problem, disconnect and reconnect the Kookaberry to your computer
SOS Resource 4: Using repeat loops and functions
One aim of good programming is to use as few lines of code as possible. This reduces programming errors (fewer instructions to get wrong) and takes up less chip memory.
The number of lines of code in the SOS programme can be reduced further by using Functions. Functions are specific tasks that you want a computer to do – such as “Move 10 steps” or look for a name in a table and return it to the programme. They can also be a specific thing requiring a number of programming actions – in this case a Dash or a Dot.
Drag the def “my function” block from the Functions menu onto the canvas and name it Dot by overwriting “my function” text in the block. This will create a separate “Dot” function in the Functions menu. Create the code for a Dot and bring it into the function. Repeat for a Dash function
Now all you have to do is to drag the Dot and Dash functions from the Functions menu into the repeat loops as shown below.
The KookaBlockly code for this resource in the downloaded zip folder is called SOSfunct.kby.py. Run the programme and then run it again with the Buzzer connected.
SOS Resource 5: Using the If statement and saving your programmes on your Kookaberry
In this resource students will learn how to save their code creations on their Kookaberries so that they can be run independently from a computer. They will also learn how to use the “if-Do” command
This will require the addition of the following instructions to any one of the programmes created in the previous resources. The example shows the additional code being used with the programme from Resource 3
Drag the “when button A is pressed” block from the Buttons menu onto the canvas. Drag “display clear” and “display show” blocks from the Display menu and place them inside the Button block. Then drag the “exit program” block from the Control menus underneath “display show”.
Drag the “when button A is pressed” block from the Buttons menu onto the canvas and insert it between the “every loop” block and the rest of the instructions. Change the button to C in the block’s drop-down menu.
Select the “display text value=” block from Display menu and drag it onto the canvas. Overtype the “Hello” text with “C to send SOS” and start the text at the coordinates shown. Repeat for the “A to Exit” text display.
[Note: the screen size is 128 pixels across and 64 pixels down]
[Tip: Don’t be afraid to use trial and error to position the text on the screen correctly. Just keep changing the “x’ or “y” values until you get it right. Remember that “x=64” and “y= 32” will start the text in the middle of the screen]
Save the file
Save your app with the .kby suffix. Go to the KookaBlockly Support page for information on saving it in Kookaberry Scripts and on your Kookaberry.
The KookaBlockly code for this Lesson Plan in the downloaded zip folder is called SOSButton.kby.py. Run the programme.
Programme your own morse code signals
Create other combinations of signals eg ABC as shown below
Blink an LED AND sound a buzzer
Modify your code to add the buzzer at P2 and have both operate at the same time. Or blink one of the embedded LED’s on the Kookaberry board as well as sound the buzzer.. [Hint: Look in the LEDs menu in KookaBlockly]
Experiment with the MorseCode App
Learn more about Morse Code by running the MorseCode app. Watch the dots and dashes being created and transmitted between Kookaberries.