Scratch Advanced – Week 3 – Cryptography

Hope everyone enjoyed last week.

This week we began a series of sessions on Cryptography. We began by demonstrating why we might use Cryptography. What is Cyrptography

What created a Scratch project to Encrypt a single word or sentence using a Reverse Cipher. Notes for this Scratch project are at: Scratch Project Notes (Reverse Cipher)

We then improved the Scratch project to Decrypt the same word or sentence back to its original form.

We discussed the limitations of a Reverse Cipher and began the introduction of the next session where we will be creating a Scratch program to Encrypt and Decrypt a word or sentence using one of the most famous ciphers the “Caesar Cipher”. Named after the Roman figure Julius Caesar.

Scratch Beginners – Ghostcatcher Game

Hi everyone,

Thanks to everyone that showed up today. Again, a big thank you to Julie for taking the session last week.

This week, we built a new game which we were calling “Ghostcatcher” We used code that we have learnt over the last two weeks and again used variables. We will continue to do this over the next couple of weeks, we will make new games but will continue to go over the basic programming concepts each week.

This was our first time creating our own Sprite rather than using one from the library. The paint editor can be great fun and you should experiment with it, creating lots of new Sprites.

Remember ! think in shapes, like we did with the ghost.


A pdf version of the full notes from todays session can be found here: CDA-S3-Challenge03-GhostCatcher.pdf

Try adding your own variables, the code is there for you to look at but why not have a go at it yourself first.

No Coderdojo Athenry next week but hope to see you all back the following Saturday the 27th.

Enjoy the Halloween break!



Python Beginners – Week 3: Functions

This week the Python group looked at Functions, Escape Characters and Boolean Operators. We also started to rewrite the Dragon’s Realm game which we will continue with after the break. Don’t forget to look at chapters 5 and 6 of “Invent Your Own Computer Games with Python” . Here are my slides from today- python session3

Scratch Beginners – Week 2 – Adding More Functions to First Game

CDA-S3-Challenge01-FirstGame-Part2We had a great crowd for our second session of Scratch beginners. Julie did a great job as lead mentor in Martha’s absence.

This week, we added lots of new functionality to our first game: make things happen when Jaws catches the Diver and keeping track of lives.

Here are the presentation slides from the day, in PDF format: CDA-S3-Challenge01-FirstGame-Part2.pdf

See you next time!

Python Beginners-Week 2: Our First Real Game

We had a good turn out at the python group again today. We did a lot of typing which some of the younger Ninjas found hard going. We won’t be doing that much again for a few weeks. We did a number guessing game which contained some concepts which are used in most computer programs. Our number guessing game is explained in chapter four of “Invent Your Own Computer Games with Python” by Al Sweigart

Scratch Advanced – Week 2 – Lets finish the Calculator.

Hope everyone enjoyed last week.

This week we are going to use a drawing application or msPaint, whichever people prefer to use to finish the Calculator off properly.

What we need to do is set the Background in the Calculator to a picture of a real calculator, something like this one…



And then using or any other graphics tool we are going to cut out the different numbers and save them all of to seperate files and then use these files as the Sprites.

You should end up with loads of these…

Image        Image

Do one for each number, one for +, -, X and divide. Oh and don’t forget the dot 🙂

If any one is feeling adventurous we might even try and do something with Memory.

Python Beginners-Week 1

We had a slow start to the Python session due to Wi-Fi and installation issues. However once we got moving we managed to cover variables including strings, math operators and inputs and outputs.
Ninjas are encouraged to read the first three chapters of Invent Your Own Computer Games with Python by Al Sweigart, which is available at .
Next week we will be looking at loops and decisions in a number guessing game and comparing it to a similar scratch program.

Here are my slides from Week-1

Scratch Beginners – Week 1- First Game “Jaws”

We had a great crowd for our first session today in Scratch beginners. Thank you all for coming and for your patience while we got everyone sorted out with downloading Scratch 2.

We started today with our first game”Jaws”, as well as learning how to write commands to move our sprites, we took a brief look at the interface for Scratch 2.


We also took a first look at some fundamental concepts that we will be using throughout the year. Today we looked at the X and Y axis as well as the number of degrees in a circle.








Here are the presentation slides from the day, in PDF format: CDA-S3-Challenge01-FirstGame-Part1.pdf

I hope you all enjoyed today and hope to see you all again over the next couple of weeks!

Scratch Advanced – Week 1 – Calculator.

Hi all and welcome back to what we hope will be an exciting year in Coder Dojo Athenry.

We will be using Scratch 2 this year. So the first thing that we need to do is install it.

There are two Applications that you need to install:

1. AdobeAir

2. Scratch2

I will have all the Versions that I can find on USB, which should cover both Windows and Mac. I have installed the Windows version, so I know that one works. I won’t have tested the Mac version though.

Scratch2 introduces the idea of making your own Blocks of code that you can then use in your programs. So for the first week we are going to try these out and see how they can help us write Code once but use it many times.

And for that we need a project to work on – A Calculator.

  • We will learn about Functions (Code Blocks in Scratch2)
  • We will learn about passing information into Functions

We are going to design and build a fully functioning Calculator that can Add, Subtract, Multiply and Divide. If you get really adventurous you can add some other functions as well – percentages maybe?

Like you I haven’t written it yet, so it going to be a bit scary tomorrow as we have to make it all up as we go along, but hey, you’re the advanced crowd, and should be able to handle that!

Once we have a fully working version I will update this blog with the full details of how and why we did what we did.

If we can get anything like the following picture, I think we are definitely Advanced…


Everything that you see on this calculator is perfectly possible in Scratch2, we will start with the four basic options of Addition, Subtraction, Multiplication and Division.