Category: Blockly

• Scratch

  Scratch is a block based programming language. You do not need to type code, but you just assemble projects with blocks of different functionality and configure those with simple entry of numbers and text. Scratch runs on a web browser and you can also interface it with some hardware. But where to start with Scratch?

  The Code Club is a UK charity that promotes computer science for young people as yourself.  They offer very comprehensive and detailed project tutorials, from small animations to a more complex  RPG(*) game.

  Here is the link to the site:

  Code Club Project Create your own world

  (*) A role-playing game (sometimes spelled roleplaying game;^[1][2] abbreviated RPG) is a game in which players assume the roles of characters in a fictional setting. Players take responsibility for acting out these roles within a narrative, either through literal acting, or through a process of structured decision-making regarding character development.^[3] Actions taken within many games succeed or fail according to a formal system of rules and guidelines.^[4] [Source: Wikipedia]

  September 18, 2019

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• Micro:bit – Catch Game Part II

  The game should now look as follows, it is already fully playable:

  

  Replacing the buttons with the accelerometer

  An important remark first, do it like a pro …

  When developming the program, do it like a pro. Professionals develop and test their software on simulators and with special test software. We do not have the later, but we have a simulator. You can check your changes immediatly when you launch your program on the simulator at the left. Do it!

  First we want to replace the buttons with values supplied by the accelerometer. Then we only need to tilt the micro:bit from left to right or bottom to top so to control the movement of our sprite. This is much more convenient. Have a look again at the code we implemented last week. We need to replace the two blocks with “on button A/B pressed” by something new comprising out of a block to change the position of the sprite, getting the values of the accelerometer and these two embedded in a “forever” loop.

  The values provided by the accelerometer vary between -1023 and +1023. That’s a lot, we only have 5 x 5 LEDS on our micro:bit. So if we do nothing, an even so small movement will always make our sprite move from one border to the other. So we need to transform this big range down to something feasable for our display. We do this by dividing the value coming from the accelerometer by 1000, an approximation for the actual range of values coming from the sensor, matching the single moves we need to. A `round` block makes sure that we get whole numbers.

  Another problem is the forever loop we will embed our acceleration block into. It is providing values too many times per second, so when we move our micro:bit even a tiny bit, it will record many movements and each of them will relocate our sprite again to the border of the display. We can avoid this if we place a pause block after taking a value from the accelerometer. In the example below, we take values every 350 ms, you may find better suited values, try it out!

  Try this out by yourself before looking at the solution. Then compare your solution with the one below.

  

  Completing the Game

  Now we can finish the game. What is still missing to get a real game?

  Here are my suggestions:

  1. We need to allow the player to do the game many times. So each time we need to delete the old target and create a new target.
  2. Get a timer that counts down, so we have a fixed time to play.
  3. We need to count the points and at the end show the score.

  The following program does that all. but I suggest that you try to figure out yourself what to do first. Most of the blocks you need, you can find in the category “Games”.

  

  TIPP: This game may work great on the simulator, but depending on your choice of values for the pauses and the transformation of values coming from the accelerator, it may not run properly on the micro:bit. In case you have problems, adjust the values for pauses, and more important for the acceleratior. Then you will get the game running on the micro:bit.

  micro:bit Curriculum: Variables

  • Why do we use data, in particular in science and mathematics?
  • What type of data do we have around us?
  • How do we track those data in real live? Which operations do we use in CS?
  • Difference between a constant and a variable
  • Which data types can constants and variable hold in Javascript? (numbers, booleans, text, objects and functions)
  • What operations do we have available to calculate with those variables? They are different depending on their type!

  Let’s make a scorekeeper and then see how we can use variables to count values coming from our sensors on board of the micro:bit

  Make a scorekeeper

  Everything counts

  October 10, 2018

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• Micro:bit – Accelerometer, the Game Blocks and a Catch Game Part I

  What we do here

  First, you get to know the acceleration sensor, then you get to build a simple game with the Game blocks available on MakeCode. Once you have mastered those to prerequisites, you continue in Part 2 to build a more sophisticated game using both accelerometer and Game blocks.

  Accelerometer

  For this game we need to use the accelerometer to sense the orientation of the micro:bit. The sensor and how to use it is described in the documentation. You find it under “Reference” or just click here on accelerometer.

  

  The accelerometer measures acceleration caused by gravity and sudden movements. Here is a sketch explaing about the three coordinates it uses to put the acceleration into numbers. In the centre you find the micro:bit board with the connector ports in the +Y direction. You can measure the acceleration in directions (X, Y, Z) at a time. The values have a range between -1023 and 1023, in the following game we assume for simplicity that it varies between -1000 and +1000.

  

  Here is the link accelerometer so that you can have a look.

  The documentation is interactive, so you can also upload a sketch to the IDE and run it there. Furthermore, you find examples that you can also easily transfer to the editor, no need to rebuild the projects.

  ToDo: Get to know sensors and how to program them.

  Get the examples running on the simulator and your micro:bit. By moving the mouse, you can simulate the various movements you can make with the micro:bit. As a next step, find the documentation for the magnetic sensor and implement a compass.

  Game module

  In the micro:bit editor under Advanced you find the category “Game”. It contains blocks to make small games.

  The small display of the micro:bit contains 5 x 5 LEDs. In the game module you can address each LED with its coordinates (x, y). You may know coordinate systems from school, they have their origin (0,0) always at the lower left corner. In computer science we normally put the origin at the upper left corner.

  

  Create your first game

  This is a simple game. It uses the 5 x 5 LED matrix and the buttons A and B. The goal of the game it is to move a randomly appearing LED with the two buttons to overlap with the LED at the centre at location (2,2).  The button A controls the horizontal position of your sprite, button B the vertical position.

  The code below implements the game basics, missing is the functionality for button B. Try to understand what is happening when you press the button. Then finish the game by coding the functionality for button B and test it thoroughly.

   

  To Do:

  • try out the program,
  • figure out what is happening when you press  Button A and
  • then add the missing functionality for button B.

  October 3, 2018

  Activity

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• More Experiments with the micro:bit II

  If you have completed all activities from the previous week, you can implement the following two projects as well:

  Temperature Activity

  

  The micro:bit has many sensors on board, also a temperature sensor. Here you will use it to measure the environmental temperature. Click on the attached link to go the page with the instructions on how to program your activity.

  Temperature Activity

  Some background: Computational Concepts I

  Once you have done one or two projects, it may be time to get to know some key computational ideas that will help you to modify exisiting projects and also create your own. Have a look here

  Die Roll Activity

  

  This small project allows you to build an electronic die. When shaking the micro:bit, it will show you a number, like on a real physical die. This small program contains a variable and a series of if conditions. When implementing the program, focus on the use of variables and the if conditions. You find some more information about these two concepts on the following page.

  Click on the attached link to go the page with the instructions on how to program your activity.

  Die Roll Activity

  September 24, 2018

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