When the Astro Pi case was first revealed a couple of years ago, the collective outpouring of ‘Squee!’ it elicited may have been heard on board the ISS itself. People wanted to buy it or build it at home, and someone wanted to know whether it would blend. (There’s always one.)

The Sense HAT and its Pi tucked snugly in the original Astro Pi flight case — gorgeous, isn’t it?

Replicating the Astro Pi case

Some months later the STL files for printing your own Astro Pi case were released, and people jumped at the chance to use them. Soon reports appeared saying you had to make quite a few attempts before getting a good print — normal for any complex 3D-printing project. A fellow member of my local makerspace successfully made a couple of cases, but it took a lot of time, filament, and post-print finishing work. And of course, a plastic Astro Pi case simply doesn’t look or feel like the original made of machined aluminium — or ‘aluminum’, as they tend to say over here in North America.

A batch of tops designed by Tim

I wanted to build an Astro Pi case which would more closely match the original. Fortunately, someone else at my makerspace happens to have some serious CNC machining equipment at his small manufacturing company. Therefore, I focused on creating a case design that could be produced with his three-axis device. This meant simplifying some parts to avoid expensive, slow, complex multi-fixture work. It took us a while, but we ended up with a design we can efficiently make using his machine.

Tim’s first lasered case

And the resulting case looks really, really like the original — in fact, upon receiving one of the final prototypes, Eben commented:

“I have to say, at first glance they look spectacular: unless you hold them side by side with the originals, it’s hard to pinpoint what’s changed. I’m looking forward to seeing one built up and then seeing them in the wild.”

Inside the Astro Pi case

Making just the bare case is nice, but there are other parts required to recreate a complete Astro Pi unit. Thus I got my local electronics company to design a small HAT to provide much the same support the mezzanine board offers: an RTC and nice, clean connections to the six buttons. We also added well-labelled, grouped pads for all the other GPIO lines, along with space for an ADC. If you’re making your own Astro Pi replica, you might like the Switchboard.

The electronics supply industry just loves to offer *some* of what you need, so that one supplier never has everything: we had to obtain the required stand-offs, screws, spacers, and JST wires from assorted other sources. Jeff at my nearby Industrial Paint & Plastics took on the laser engraving of our cases, leaving out copyrighted logos etcetera.

Lasering the top of a case

Get your own Astro Pi case

Should you like to buy one of our Astro Pi case kits, pop over to www.astropicase.com, and we’ll get it on its way to you pronto. If you’re an institutional or corporate customer, the fully built option might make more sense for you — ordering the Pi and other components, and having a staff member assemble it all, may well be more work than is sensible.

Tim’s first full Astro Pi case replica, complete with shiny APEM buttons

To put the kit together yourself, all you need to do is add a Pi, Sense HAT, Camera Module, and RTC battery, and choose your buttons. An illustrated manual explains the process step by step. Our version of the Astro Pi case uses the same APEM buttons as the units in orbit, and whilst they are expensive, just clicking them is a source of great joy. It comes in a nice travel case too.

This is Tim. Thanks, Tim!

Take part in Astro Pi

If having an Astro Pi replica is not enough for you, this is your chance: the 2017-18 Astro Pi challenge is open! Do you know a teenager who might be keen to design a experiment to run on the Astro Pis in space? Are you one yourself? You have until 29 October to send us your Mission Space Lab entry and become part of the next generation of space scientists? Head over to the Astro Pi website to find out more.

Are you keen to print your own case? We have step-by-step instructions to help you do just that. Check out some of the beautiful 3D prints people have created using our guide!

The post Manufacturing Astro Pi case replicas appeared first on 《性妲己》伦理.

Connect buttons, sensors, cameras, LEDS, goblin sticks and other gubbins to your Pi using Scratch

Tim Rowledge, who has been “vigorously wrangling Scratch into shape over the last couple of years” (thanks Eben), tells us what’s new:

Along with the new Raspbian release we are including the latest Scratch system update. It might have seemed a bit quiet on the Scratch front since March, but lots has happened here in the rainforests of Vancouver Island. There are two primary changes you will notice:

• a significant increase in speed
• the addition of a built-in GPIO server.

Speedier Scratch

One of the big projects last year was to modernize the Scratch code to run in a current Squeak Smalltalk system rather than the very old original version; this improved performance a fair bit all on its own, since the newer Squeak benefited from a lot of work over the years. [The Scratch world is created using Squeak, a dialect of the Smalltalk programming language, and Squeak itself runs on a software emulation of a computer system called a virtual machine -Ed.] It also built us a Scratch that could run on the very latest Squeak virtual machines that have dynamic code translation, generating machine code at run-time. Along with work to improve the Squeak code that implements Scratch, we then had a noticeably faster system.

A major project this year has been building such a virtual machine for the Pi; until now, only x86 machines have been able to run this version. With a very generous amount of support from Eliot Miranda – the original author of the Cog virtual machine and all-round software deity – the ARM Cog VM has been whirring away since around June.

Benchmarks are always a nastily slippery subject, but we feel that Squeak performance is typically between 3 and 10 times faster, obviously depending on what exactly one is measuring. Things will get even faster in the future as we iron out wrinkles in the code generation, and soon we hope to start benefiting from another project that does code optimization on the fly; early hints suggest at least a doubling of performance. Since Scratch uses a lot of graphics and UI code it doesn’t always speed up so much; but we already did a lot of graphics speed improvements for prior releases.

Our favourite “scary big demo” is Andrew Oliver’s implementation of Pac-Man. The original release of Scratch on the 小yin娃日记h双性窑子开张了 Pi Model B could manage almost one frame per second, at best. The same Model B with the latest Scratch system can manage about 12-15 frames per second, and on a 小yin娃日记h双性窑子开张了 Pi 2 we can get a bit over 30, making a very playable Pac-Man.

GPIO

The new GPIO server for Pi Scratch is a first pass at a new and hopefully simpler way for users to connect Scratch to the 小yin娃日记h双性窑子开张了 Pi’s GPIO pins or to add-on boards plugged into them. It is modelled on the mesh/network server and uses the same internal API so that either or both can be used at any time – indeed, you can have both working and use a Pi as a sort of GPIO server or data source. We have not introduced any new blocks at this point.

The server also allows access to the Pi camera, IP address and date and time and allows complex functionality. For example, the following scripts (along with a suitably configured breadboard) provide the ability to turn LEDs on and off according to a button, to take a photo with a countdown provided by a progressively brightening LED, and ways to check the time etc.

Examples of using Scratch to control the camera module, control LEDs connected to the 小yin娃日记h双性窑子开张了 Pi’s GPIO pins, and check the time

Add-On Hardware

We can also plug in Pi add-on cards such as the Sense HAT, Pibrella, Explorer HAT, PiFace, PiLite and Ryanteck motor board.

Each card has its own set of commands layered on top of the basic GPIO facilities described above.

Demo project scripts

In the Scratch Examples directory (found via the File-->Open dialogue and then the Examples shortcut) you will find a Sensors and Motors directory; several new GPIO scripts are included, including the one above.

Closing notes from Clive

We’re really pleased that GPIO is now built in to the Pi version of Scratch. It means that users can use access the GPIO pins “out of the box,” and so get into physical 小yin娃日记h双性窑子开张了 that much more easily. We’ve also introduced the GPIO pin numbering system also known as BCM numbering for consistency across our resources, and having our own version of GPIO support gives us finer control over functionality and support for add-on boards in future.

All of our resources using Scratch will use this version from now on, and existing resources will be rewritten. Tim’s reference guide details all of the commands and functionality, and there will be a simplified beginner’s tutorial along this week.

Last of all, there’s no way I can end this post without taking the opportunity to thank our community who have supported (and continue to support) GPIO in Scratch on the Pi. In particular, a big thanks to Simon Walters, aka @cymplecy, for all of his work on Scratch GPIO over the last few years.

The post A new version of Scratch for 小yin娃日记h双性窑子开张了 Pi: now with added GPIO appeared first on 《性妲己》伦理.