Coding the Micro Bit Creating your own Handheld

Coding the Micro: Bit Creating your own Handheld Games Console www. computerscienceuk. com

Learning Habits Which learning habits will be important for this unit of work and why? Adapting : Reflecting and making changes Noticing details Empathising… …with feelings and views Listening… …to understand Collaboration: Working effectively with others Independence: Working effectively alone Making links… …and recognising relevance Effective use of time Imagining… …how things could be and seeing a range of possibilities Meta Learning: Talking about how you have been learning Managing distractions… …and sustaining concentration Perseverance: Overcoming frustration and difficulty Reasoning: Thinking rigorously, methodically and giving explanations. Questioning: Asking questions to get below the surface Distilling… …what you have learnt and what you need to learn Imitation: Picking up good habits from others Capitalising: Using resources purposefully Planning… …your learning in advance www. computerscienceuk. com

Lesson Objectives • To develop our skills in programming using the blocks language • To understand the purpose of variables • To develop understanding of coordinates and see how they are used in developing graphical programs. • Success Criteria • ALL: To develop a simple pong game turning the device into a handheld console. • MOST/SOME: To be able to develop the code to solve a number of challenges. Literacy – Key Words Variables A memory store in a program (think of it as a box which stores a piece of data) Coordinates A system which enables us to locate the position of an object using a horizontal (x) and vertical (y). For example a pixel on a screen www. computerscienceuk. com

Lets Create Pong! To create a Pong we need to understand a few things. 1. Coordinates Whenever we create computer games, we will need to draw items on the screen and update their position over time. The position of screen objects is always described with screen coordinates and the Micro: Bit is no exception. The LEDs on the Micro: Bit can be thought of as screen pixels and each LED can be described using an X and Y coordinate. X-Coordinates Y-Coordinates This LED has the coordinate (3, 2) www. computerscienceuk. com

Lets Create Pong! 2. X-Velocity / Y-Velocity So we should now be OK with the idea of X and X positions of the LED’s on the Micro: Bit. The next thing to understand is that when we wish to update the position of a screen object (lit up LED), we do so using X and Y velocities. This is not as scary as it sounds. It simply stands for a number which we use to add to an item’s coordinate so that it can be repositioned on the screen and therefore appear to be moving. For example, if the LED (3, 2) had an X-Velocity of 1, it would move to the right 1 place each time the screen was updated. X-Coordinates Y-Coordinates This LED has the coordinate (3, 2) www. computerscienceuk. com

Lets Create Pong! 3. Variables So that we can keep track of the item’s coordinates and other data, variables are required. Variables are simply stores of data (think of them like boxes to store a stuff in). To create a variable and store data in them, we will need to use the following scripts: This allows us to create new variables and give them names This allows us to set our variables to particular values (ie store data in the variable) www. computerscienceuk. com

Step 1 - Coding Pong • Go to www. microbit. co. uk/create-code • Click on ‘New Project’ • Create the following script: This scripts will create the start screen, plotting the ball and paddle to start the game. 1. Create 5 variables 2. Set each variable to the values you see in the example script. 3. Use a ‘Show LEDs’ script and tick the bottom row. 4. Plot the ball using the ball’s x and y coordinates. 5. Plot the Paddle using the paddle’s y coordinate (hardcode the x coordinate to 0) www. computerscienceuk. com

Step 1 - Coding Pong • Next, create the following scripts: These scripts move the paddle up and down when the appropriate button is pressed. 1. Create a ‘when the A/B button is pressed’ script 2. Un-plot the paddle from the screen 3. If the paddle is not already at the top / bottom of the screen, change its y position so that it moves up /down 4. Otherwise, redraw the paddle in the same positon as before (ie. no movement). www. computerscienceuk. com

Step 1 - Coding Pong • Finally, create the following script: This script moves the ball around the screen, bouncing off walls and the paddle, or shows an X if the paddle misses the ball. 1. 2. 3. 4. 5. 6. In a forever script, begin by un-plotting the ball Then, in an IF statement, code the condition that if the ball is at the right hand side of the screen, change the x-velocity so that it moves left (bounces back) – otherwise let the ball continue to move left. Then in another IF statement, code the condition that if the ball is at the left side of the screen and level with the paddle, change the x-velocity so that it bounces off the paddle, otherwise clear the screen and show a cross (ie. game over). Then in a final IF statement, code the condition that if the ball is at the top or bottom of the screen, change the y-velocity so that it bounces back into play. Finally, update the position of the ball with the updated velocities and replot the ball. Pause for a short while and repeat. www. computerscienceuk. com

Step 2 – Compiling and Flashing If its working it is time to COMPILE and FLASH. • Press the COMPILE button. • Once the HEX file has downloaded, go into your documents and find it. • Now plug in your device to an available USB port. • Open the device up as if it were a USB memory stick. • Now drag the HEX file into the opened device folder (as if you were transferring files to a memory stick). • Now the FLASHING will be complete and you can try out your software on your Micro: Bit. www. computerscienceuk. com

Your Working Handheld Games’pong’sole www. computerscienceuk. com

Class Tasks Challenge 1 Speed up the game so that the ball moves faster. Challenge 2 Add a variable called score and add a script so that each time the paddle and ball meet, the score variable is updated by 1 and this score is shown at the end of the game. Challenge 3 Add a script which will pause the game when both the A and B buttons are pressed. www. computerscienceuk. com

Class Tasks – Possible Solutions Challenge 1 + Challenge 2 Challenge 3 + + www. computerscienceuk. com