Author Archives: Alex Bate

Using Raspberry Pi for deeper learning in education

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Using deeper learning as a framework for transformative educational experiences, Brent Richardson outlines the case for a pedagogical approach that challenges students using a Raspberry Pi. From the latest issue of Hello World magazine — out today!

A benefit of completing school and entering the workforce is being able to kiss standardised tests goodbye. That is, if you don’t count those occasional ‘prove you watched the webinar’ quizzes some supervisors require.

In the real world, assessments often happen on the fly and are based on each employee’s ability to successfully complete tasks and solve problems. It is often obvious to an employer when their staff members are unprepared.

Formal education continues to focus on accountability tools that measure base-level proficiencies instead of more complex skills like problem-solving and communication.

One of the main reasons the U.S. education system is criticised for its reliance on standardised tests is that this method of assessing a student’s comprehension of a subject can hinder their ability to transfer knowledge from an existing situation to a new situation. The effect leaves students ill-prepared for higher education and the workforce.

A study conducted by the National Association of Colleges and Employers found a significant gap between how students felt about their abilities and their employer’s observations. In seven out of eight categories, students rated their skills much higher than their prospective employers had.

Some people believe that this gap continues to widen because teaching within the confines of a standardised test encourages teachers to narrow their instruction. The focus becomes preparing students with a limited scope of learning that is beneficial for testing.

With this approach to learning, it is possible that students can excel at test-taking and still struggle with applying knowledge in new ways. Educators need to have the support to not only prepare students for tests but also to develop ways that will help their students connect to the material in a meaningful manner.

In an effort to boost the U.S. education system’s ability to increase the knowledge and skills of students, many private corporations and nonprofits directly support public education. In 2010, the Hewlett Foundation went so far as to develop a framework called ‘deeper learning’ to help guide its education partners in preparing learners for success.

The principles of deeper learning

Deeper learning focuses on six key competencies:

    1. Master core academic content
    2. Think critically and solve
      complex problems
    3. Work collaboratively
    4. Communicate effectively
    5. Learn how to learn
    6. Develop academic mindsets

This framework ensures that learners are active participants in their education. Students are immersed in a challenging curriculum that requires them to seek out and acquire new information, apply what they have learned, and build upon that to create new knowledge.

While deeper learning experiences are important for all students, research shows that schools that engage students from low-income families and students of colour in deeper learning have stronger academic outcomes, better attendance and behaviour, and lower dropout rates. This results in higher graduation rates, and higher rates
of college attendance and perseverance than comparison schools serving similar students. This pedagogical approach is one we strive to embed in all our work at Fab Lab Houston.

A deeper learning timelapse project

The importance of deeper learning was undeniable when a group of students I worked with in Houston built a solar-powered time-lapse camera. Through this collaborative project, we quickly found ourselves moving beyond classroom pedagogy to a ‘hero’s journey’ — where students’ learning paths echo a centuries-old narrative arc in which a protagonist goes on an adventure, makes new friends, encounters roadblocks, overcomes adversity, and returns home a changed person.

In this spirit, we challenged the students with a simple objective: ‘Make a device to document the construction of Fab Lab Houston’. In just one sentence, participants understood enough to know where the finish line was without being told exactly how to get there. This shift in approach pushed students to ask questions as they attempted to understand constraints and potential approaches.

Students shared ideas ranging from drone video to photography robots. Together everyone began to break down these big ideas into smaller parts and better define the project we would tackle together. To my surprise, even the students that typically refused to do most things were excited to poke holes in unrealistic ideas. It was decided, among other things, that drones would be too expensive, robots might not be waterproof, and time was always a concern.

The decision was made to move forward with the stationary time-lapse camera, because although the students didn’t know how to accomplish all the aspects of the project, they could at least understand the project enough to break it down into doable parts and develop a ballpark budget. Students formed three teams and picked one aspect of the project to tackle. The three subgroups focused on taking photos and converting them to video, developing a remote power solution, and building weatherproof housing.

A group of students found sample code for Raspberry Pi that could be repurposed to take photos and store them sequentially on a USB drive. After quick success, a few ambitious learners started working to automate the image post-processing into video. Eventually, after attempting multiple ways to program the computer to dynamically turn images into video, one team member discovered a new approach: since the photos were stored with a sequential numbering system, thousands of photos could be loaded into Adobe Premiere Pro straight off the USB with the ‘Automate to Sequence’ tool in Premiere.

A great deal of time was spent measuring power consumption and calculating solar panel and battery size. Since the project would be placed on a pole in the middle of a construction site for six months, the students were challenged with making their solar-powered time-lapse camera as efficient as possible.

Waking the device after it was put into sleep mode proved to be more difficult than anticipated, so a hardware solution was tested. The Raspberry Pi computer was programmed to boot up when receiving power, take a picture, and then shut itself down. With the Raspberry Pi safely shut down, a timer relay cut power for ten minutes before returning power and starting the cycle again.

Finally, a waterproof container had to be built to house the electronics and battery. To avoid overcomplicating the process, the group sourced a plastic weatherproof ammunition storage box to modify. Students operated a 3D printer to create custom parts for the box.

After cutting a hole for the camera, a small piece of glass was attached to a 3D-printed hood, ensuring no water entered the box. On the rear of the box, they printed a part to hold and seal the cable from the solar panel where it entered the box. It only took a few sessions before the group produced a functioning prototype. The project was then placed outside for a day to test the capability of the device.

The test appeared successful when the students checked the USB drive. The drive was full of high-quality images captured every ten minutes. When the drive was connected back to Raspberry Pi, a student noticed that all the parts inside the case moved. The high temperature on the day of the test had melted the glue used to attach everything. This unexpected problem challenged students to research a better alternative and reattach the pieces.

Once the students felt confident in their device’s functionality, it was handed over to the construction crew, who installed the camera on a twenty-foot pole. The installation went smoothly and the students anxiously waited to see the results.

Less than a week after the camera went up, Houston was hit hard with the rains brought on by hurricane Harvey. The group was nervous to see whether the project they had constructed would survive. However, when they saw that their camera had survived and was working, they felt a great sense of pride.

They recognised that it was the collaborative effort of the group to problem-solve possible challenges that allowed their camera to not only survive but to capture a spectacular series of photos showing the impact of the hurricane in the location it was placed.

BakerRipleyTimeLapse2

This is “BakerRipleyTimeLapse2” by Brent Richardson on Vimeo, the home for high quality videos and the people who love them.

A worthwhile risk

Overcoming many hiccups throughout the project was a great illustration of how the students learned how to learn and
to develop an academic mindset; a setback that at the beginning of the project might have seemed insurmountable was laughable in the end.

Throughout my experience as a classroom teacher, a museum educator, and now a director of a digital makerspace, I’ve seen countless students struggle to understand the relevance of learning, and this has led me to develop a strong desire to expand the use of deeper learning.

Sometimes it feels like a risk to facilitate learning rather than impart knowledge, but seeing a student’s development into a changed person, ready to help someone else learn, makes it worth the effort. Let’s challenge ourselves as educators to help students acquire knowledge and use it.

Get your FREE copy of Hello World today

Issue 12 of Hello World is available now as a FREE PDF download. UK-based educators can also subscribe to receive Hello World directly to their door in all its shiny printed goodness. Visit the Hello World website for more information.

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Don’t forget about Steam Link on Raspberry Pi

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Connect your gaming PC to your TV with ease, thanks to Steam Link and Raspberry Pi.

A Steam Link to the past

Back in 2018, we asked Simon, our Asset Management Assistant Keeper of the Swag, Organiser of the Stuff, Lord Commander of the Things to give Steam Link on Raspberry Pi a try for us, as he likes that sort of thing and was probably going to do it anyway.

Valve’s Steam Link, in case you don’t know, allows users of the gaming distribution platform Steam to stream video games from their PC to a display of their choice via their home network, with no need for cumbersome wires and whatnot.

Originally produced as a stand-alone box in 2018, Valve released this tool as a free download to all Raspberry Pi users, making it accessible via a single line of code. Nice!

The result of Simon’s experiment was positive: he reported that setting up Steam Link was easy, and the final product was a simple and affordable means of playing PC games on his TV, away from his PC in another room.

And now…

Well, it’s 2020 and since many of us are staying home lately, so we figured it would be nice to remind you all that this streaming service is still available.

To set up Steam Link on your Raspberry Pi, simply enter the following into a terminal window:

sudo apt update
sudo apt install steamlink

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How to use a button with a Raspberry Pi

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Here’s our latest How to use video, showing you how to connect a button to your Raspberry Pi.

HOW TO USE a BUTTON with Raspberry Pi

Learn how to use a tactile button with your Raspberry Pi. They’re a great addition to any digital making project! Subscribe to our YouTube channel: http://rp…

Connect a button to Raspberry Pi

Attaching a button to your Raspberry Pi is a great way of introducing digital making into your coding experience. Use it to play music, turn lights on and off, or even shut down your device.

Follow our other How to use videos to learn how to use a servo motor, LED, and Raspberry Pi camera module with your Raspberry Pi. Try linking them together to build something grander, such as a digital camera, a robot, or a music box.

How to use Raspberry Pi

You’ll find a full list of our current How to use videos here – be sure to subscribe to our channel for more content as we release it.

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Create Boing!, our Python tribute to Pong

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Following on from yesterday’s introduction to Pong, we’re sharing Boing!, the Python-based tribute to Pong created by Eben Upton exclusively for Code the Classics. Read on to get a detailed look at the code for Boing!

You can find the download link for the Boing! code in the Code the Classics book, available now in a variety of formats. Be sure to stick with today’s blog post until the end, for a special Code the Classics offer.

From Pong to Boing!

To show how a game like Pong can be coded, we’ve created Boing! using Pygame Zero, a beginner-friendly tool for making games in Python. It’s a good starting point for learning how games work – it takes place on a single screen without any scrolling, there are only three moving objects in the game (two bats and a ball), and the artificial intelligence for the computer player can be very simple – or even non-existent, if you’re happy for the game to be multiplayer only. In this case, we have both single-player and two-player modes.

The code can be divided into three parts. First, there’s the initial startup code. We import from other Python modules so we can use their code from ours. Then we check to make sure that the player has sufficiently up-to-date versions of Python and Pygame Zero. We set the WIDTH and HEIGHT variables, which are used by Pygame Zero when creating the game window. We also create two small helper functions which are used by the code.

The next section is the largest. We create four classes: Impact, Ball, Bat, and Game. The first three classes inherit from Pygame Zero’s Actor class, which amongst other things keeps track of an object’s location in the game world, and takes care of loading and displaying sprites. Bat and Ball define the behaviour of the corresponding objects in the game, while Impact is used for an animation which is displayed briefly whenever the ball bounces off something. The Game class’s job is to create and keep track of the key game objects, such as the two bats and the ball.

Further down, we find the update and draw functions. Pygame Zero calls these each frame, and aims to maintain a frame rate of 60 frames per second. Gameplay logic, such as updating the position of an object or working out if a point has been scored, should go in update, while in draw we tell each of the Actor objects to draw itself, as well as displaying backgrounds, text, and suchlike.

Our update and draw functions make use of two global variables: state and game. At any given moment, the game can be in one of three states: the main menu, playing the game, or the game-over screen. The update and draw functions read the state variable and run only the code relevant to the current state. So if state is currently State.MENU, for example, update checks to see if the SPACE bar or the up/down arrows are pressed and updates the menu accordingly, and draw displays the menu on the screen. The technical term for this kind of system is ‘finite state machine’.

The Game class’s job is to create and keep track of the key game objects

The game variable references an instance of the Game class as described above. The __init__ (constructor) method of Game optionally receives a parameter named controls. When we create a new Game object for the main menu, we don’t provide this parameter and so the game will therefore run in attract mode – in other words, while you’re on the main menu, you’ll see two computer-controlled players playing against each other in the background. When the player chooses to start a new game, we replace the existing Game instance with a new one, initialising it with information about the controls to be used for each player – if the controls for the second player are not specified, this indicates that the player has chosen a single-player game, so the second will be computer-controlled.

Two types of movement

In Boing!, the Bat and Ball classes inherit from Pygame Zero’s Actor class, which provides a number of ways to specify an object’s position. In this game, as well as games in later chapters, we’re setting positions using the x and y attributes, which by default specify where the centre of the sprite will be on the screen. Of course, we can’t just set an object’s position at the start and be done with it – if we want it to move as the game progresses, we need to update its position each frame. In the case of a Bat, movement is very simple. Each frame, we check to see if the relevant player (which could be a human or the computer) wants to move – if they do, we either subtract or add 4 from the bat’s Y coordinate, depending on whether they want to move up or down. We also ensure that the bat does not go off the top or bottom of the screen. So, not only are we only moving along a single axis, our Y coordinate will always be an integer (i.e. a whole number). For many games, this kind of simple movement is sufficient. Even in games where an object can move along both the X and Y axes, we can often think of the movement along each axis as being separate. For example, in the next chapter’s game, Cavern, the player might be pressing the right arrow key and therefore moving along the X axis at 4 pixels per frame, while also moving along the Y axis at 10 pixels per frame due to gravity. The movement along each axis is independent of the other.

Able to move at any angle, the ball needs to move at the same speed regardless of its direction

For the Ball, things get a bit more complicated. Not only can it move at any angle, it also needs to move at the same speed regardless of its direction. Imagine the ball moving at one pixel per frame to the right. Now imagine trying to make it move at a 45° angle from that by making it move one pixel right and one pixel up per frame. That’s a longer distance, so it would be moving faster overall. That’s not great, and that’s before we’ve even started to think about movement in any possible direction.

The solution is to make use of vector mathematics and trigonometry. In the context of a 2D game, a vector is simply a pair of numbers: X and Y. There are many ways in which vectors can be used, but most commonly they represent positions or directions.

You’ll notice that the Ball class has a pair of attributes, dx and dy. Together these form a vector representing the direction in which the ball is heading. If dx and dy are 1 and 0.5, then each time the ball moves, it’ll move by one pixel on the X axis and a half a pixel on the Y axis. What does it mean to move half a pixel? When a sprite is drawn, Pygame Zero will round its position to the nearest pixel. So the end result is that our sprite will move down the screen by one pixel every other frame, and one pixel to the right every frame (Figure 1).

We still need to make sure that our object moves at a consistent speed regardless of its direction. What we need to do is ensure that our direction vector is always a ‘unit vector’ – a vector which represents a distance of one (in this case, one means one pixel, but in some games it will represent a different distance, such as one metre). Near the top of the code you’ll notice a function named normalised. This takes a pair of numbers representing a vector, uses Python’s math.hypot function to calculate the length of that vector, and then divides both the X and Y components of the vector by that length, resulting in a vector which points in the same direction but has a length of one (Figure 2).

Vector maths is a big field, and we’ve only scratched the surface here. You can find many tutorials online, and we also recommend checking out the Vector2 class in Pygame (the library on top of which Pygame Zero is built).

Try Boing!

Update Raspbian to try Boing! and other Code the Classics games on your Raspberry Pi.

The full BOING! tutorial, including challenges, further explanations, and a link to the downloadable code can be found in Code the Classics, the latest book from Raspberry Pi Press.

We’re offering £1 off Code the Classics if you order it before midnight tomorrow from the Raspberry Pi Press online store. Visit the store now, or use the discount code PONG at checkout if you make a purchase before midnight tomorrow.

As always, Code the Classics is available as a free PDF from the Wireframe website, but we highly recommend purchasing the physical book, as it’s rather lovely to look at and would make a great gift for any gaming and/or coding enthusiast.

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Build a Raspberry Pi Zero W Amazon price tracker

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Have you ever missed out on a great deal on Amazon because you were completely unaware it existed? Are you interested in a specific item but waiting for it to go on sale? Here’s help: Devscover’s latest video shows you how to create an Amazon price tracker using Raspberry Pi Zero W and Python.

Build An Amazon Price Tracker With Python

Wayne from Devscover shows you how to code a Amazon Price Tracker with Python! Get started with your first Python project. Land a job at a big firm like Google, Facebook, Twitter or even the less well known but equally exciting big retail organisations or Government with Devscover tutorials and tips.

By following their video tutorial, you can set up a notification system on Raspberry Pi Zero W that emails you every time your chosen item’s price drops. Very nice.

Devscover’s tutorial is so detailed that it seems a waste to try and summarise it here. So instead, why not make yourself a cup of tea and sit down with the video? It’s worth the time investment: if you follow the instructions, you’ll end up with a great piece of tech that’ll save you money!

Remember, if you like what you see, subscribe to the Devscover YouTube channel and give them a thumbs-up for making wonderful Raspberry Pi content!

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Build a Raspberry Pi laser scanner

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You really don’t need anything too fancy to build this Raspberry Pi laser scanner, and that’s why we think it’s pretty wonderful.

Rasperry Pi 3D Laser Scanner

Cornell University: ECE 5725 Michael Xiao and Thomas Scavella

Building a Raspberry Pi laser scanner

The ingredients you’ll need to build the laser scanner are:

  • Raspberry Pi
  • Raspberry Pi Camera Module v2
  • Stepper motor and driver
  • Line laser
  • Various LEDs, resistors, and wires
  • Button

To complete the build, access to a 3D printer and laser cutter would come in handy. If you don’t have access to such tools, we trust you to think of an alternative housing for the scanner. You’re a maker, you’re imaginative — it’s what you do.

How does the laser scanner work?

The line laser projects a line an object, highlighting a slice of it. The Raspberry Pi Camera Module captures this slice, recording the shape of the laser line on the object’s surface. Then the stepper motor rotates the object. When the object has completed a full rotation and the camera has taken an image of every slice, the Raspberry Pi processes all the images to create one virtual 3D object.

Instructables user mfx2 has written a wonderful tutorial for the project, which also includes all files needed to build and program your own version.

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