Tag Archives: emulators

[$] A look at terminal emulators, part 2

Post Syndicated from jake original https://lwn.net/Articles/751763/rss

A comparison of the feature sets for a handful of terminal emulators was
the subject of a recent article; here I follow that up by
examining the performance of those terminals.

This might seem like a
lesser concern, but as it turns out, terminals exhibit surprisingly
high latency for such fundamental programs. I also examine what is
traditionally considered “speed” (but is really scroll bandwidth) and
memory usage, with the understanding that the impact of memory use
is less than it was when I looked at this a decade ago (in
French).

Subscribers can read on for part 2 from guest author Antoine Beaupré.

[$] A look at terminal emulators, part 1

Post Syndicated from jake original https://lwn.net/Articles/749992/rss

Terminals have a special place in computing history, surviving along
with the command line in the face of the rising ubiquity of graphical
interfaces. Terminal emulators have replaced
hardware
terminals
, which themselves were upgrades from punched
cards and toggle-switch inputs. Modern distributions now ship with a
surprising variety of terminal emulators. While some people may be
happy with the default terminal provided by their desktop environment,
others take great pride at using exotic software for running their
favorite shell or text editor. But as we’ll see in this two-part series,
not all terminals are created equal:
they vary wildly in terms of functionality, size, and
performance.

MagPi 67: back to the future with retro computing on your Pi

Post Syndicated from Rob Zwetsloot original https://www.raspberrypi.org/blog/magpi-67/

Hey folks, Rob from The MagPi here! While we do love modern computers here at The MagPi, we also have a soft spot for the classic machines of yesteryear, which is why we have a huge feature on emulating and upcycling retro computers in The MagPi issue 67, out right now.

The MagPi 67 Retro Gaming Privacy Security

Retro computing and security in the latest issue of The MagPi

Retro computing

Noted retro computing enthusiast K.G. Orphanides takes you through using the Raspberry Pi to emulate these classic machines, listing the best emulators out there and some of the homebrew software people have created for them. There’s even a guide on how to put a Pi in a Speccy!

The MagPi 67 Retro Gaming Privacy Security

Retro fun for all

While I’m a bit too young to have had a Commodore 64 or a Spectrum, there are plenty of folks who read the mag with nostalgia for that age of computing. And it’s also important for us young’uns to know the history of our hobby. So get ready to dive in!

Security and more

We also have an in-depth article about improving your security and privacy online and on your Raspberry Pi, and about using your Pi to increase your network security. It’s an important topic, and one that I’m pretty passionate about, so hopefully you’ll find the piece useful!

The new issue also includes our usual selection of inspiring projects, informative guides, and definitive reviews, as well as a free DVD with the latest version of the Raspberry Pi Desktop for Windows and Apple PCs!

Get The MagPi 67

Issue 67 is available today from WHSmith, Tesco, Sainsbury’s, and Asda. If you live in the US, head over to your local Barnes & Noble or Micro Center in the next few days for a print copy. You can also get the new issue online from our store, or digitally via our Android and iOS apps. And don’t forget, there’s always the free PDF as well.

New subscription offer!

Want to support the Raspberry Pi Foundation and the magazine? We’ve launched a new way to subscribe to the print version of The MagPi: you can now take out a monthly £4 subscription to the magazine, effectively creating a rolling pre-order system that saves you money on each issue.

You can also take out a twelve-month print subscription and get a Pi Zero W, Pi Zero case, and adapter cables absolutely free! This offer does not currently have an end date.

We hope you enjoy this issue! See you next time…

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I am Beemo, a little living boy: Adventure Time prop build

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/adventure-time-bmo/

Bob Herzberg, BMO builder and blogger at BYOBMO.com, fills us in on the whys and hows and even the Pen Wards of creating interactive Adventure Time BMO props with the Raspberry Pi.

A Conversation With BMO

A conversation with BMO showing off some voice recognition capabilities. There is no interaction for BMO’s responses other than voice commands. There is a small microphone inside BMO (right behind the blue dot) and the voice commands are processed by Google voice API over WiFi.

Finding BMO

My first BMO began as a cosplay prop for my daughter. She and her friends are huge fans of Adventure Time and made their costumes for Princess Bubblegum, Marceline, and Finn. It was my job to come up with a BMO.

Raspberry Pi BMO Laura Herzberg Bob Herzberg

Bob as Banana Guard, daughter Laura as Princess Bubblegum, and son Steven as Finn

I wanted something electronic, and also interactive if possible. And it had to run on battery power. There was only one option that I found that would work: the Raspberry Pi.

Building a living little boy

BMO’s basic internals consist of the Raspberry Pi, an 8” HDMI monitor, and a USB battery pack. The body is made from laser-cut MDF wood, which I sanded, sealed, and painted. I added 3D-printed arms and legs along with some vinyl lettering to complete the look. There is also a small wireless keyboard that works as a remote control.

Adventure Time BMO prop
Adventure Time BMO prop
Adventure Time BMO prop
Adventure Time BMO prop

To make the front panel button function, I created a custom PCB, mounted laser-cut acrylic buttons on it, and connected it to the Pi’s IO header.

Inside BMO - Raspberry Pi BMO Laura Herzberg Bob Herzberg

Custom-made PCBs control BMO’s gaming buttons and USB input.

The USB jack is extended with another custom PCB, which gives BMO USB ports on the front panel. His battery life is an impressive 8 hours of continuous use.

The main brain game frame

Most of BMO’s personality comes from custom animations that my daughter created and that were then turned into MP4 video files. The animations are triggered by the remote keyboard. Some versions of BMO have an internal microphone, and the Google Voice API is used to translate the user’s voice and map it to an appropriate response, so it’s possible to have a conversation with BMO.

The final components of Raspberry Pi BMO Laura Herzberg Bob Herzberg

The Raspberry Pi Camera Module was also put to use. Some BMOs have a servo that can pop up a camera, called GoMO, which takes pictures. Although some people mistake it for ghost detecting equipment, BMO just likes taking nice pictures.

Who wants to play video games?

Playing games on BMO is as simple as loading one of the emulators supported by Raspbian.

BMO connected to SNES controllers - Raspberry Pi BMO Laura Herzberg Bob Herzberg

I’m partial to the Atari 800 emulator, since I used to write games for that platform when I was just starting to learn programming. The front-panel USB ports are used for connecting gamepads, or his front-panel buttons and D-Pad can be used.

Adventure time

BMO has been a lot of fun to bring to conventions. He makes it to ComicCon San Diego each year and has been as far away as DragonCon in Atlanta, where he finally got to meet the voice of BMO, Niki Yang.

BMO's back panel - Raspberry Pi BMO Laura Herzberg Bob Herzberg

BMO’s back panel, autographed by Niki Yang

One day, I received an email from the producer of Adventure Time, Kelly Crews, with a very special request. Kelly was looking for a birthday present for the show’s creator, Pendleton Ward. It was either luck or coincidence that I just was finishing up the latest version of BMO. Niki Yang added some custom greetings just for Pen.

BMO Wishes Pendleton Ward a Happy Birthday!

Happy birthday to Pendleton Ward, the creator of, well, you know what. We were asked to build Pen his very own BMO and with help from Niki Yang and the Adventure Time crew here is the result.

We added a few more items inside, including a 3D-printed heart, a medal, and a certificate which come from the famous Be More episode that explains BMO’s origins.

Back of Adventure Time BMO prop
Adventure Time BMO prop
Adventure Time BMO prop
Adventure Time BMO prop

BMO was quite a challenge to create. Fabricating the enclosure required several different techniques and materials. Fortunately, bringing him to life was quite simple once he had a Raspberry Pi inside!

Find out more

Be sure to follow Bob’s adventures with BMO at the Build Your Own BMO blog. And if you’ve built your own prop from television or film using a Raspberry Pi, be sure to share it with us in the comments below or on our social media channels.

 

All images c/o Bob and Laura Herzberg

The post I am Beemo, a little living boy: Adventure Time prop build appeared first on Raspberry Pi.

Desktop Sense HAT emulator

Post Syndicated from David Honess original https://www.raspberrypi.org/blog/desktop-sense-hat-emulator/

If this post gives you a sense of déjà-vu it’s because, last month, we announced a web-based Sense HAT emulator in partnership with US-based startup Trinket.

Today, we’re announcing another Sense HAT emulator designed to run natively on your Raspberry Pi desktop, instead of inside a browser. Developed by Dave Jones, it’s intended for people who own a Raspberry Pi but not a Sense HAT. In the picture below, the sliders are used to change the values reported by the sensors while your code is running.

sense-emu

So, why do we need two versions?

  • For offline use, possibly the most common way Raspberry Pis are used in the classroom.
  • To accommodate the oldest 256 MB models of Raspberry Pi which cannot run the web version.
  • To allow you to integrate your Sense HAT program with any available Python modules, or other Raspberry Pi features such as the Camera Module.

The emulator will come pre-installed in the next Raspbian release but, for now, you can just install it by typing the commands below into a terminal window:

sudo apt-get update
sudo apt-get install python-sense-emu python3-sense-emu python-sense-emu-doc sense-emu-tools -y

You can then access it from the Desktop menu, under Programming.

The emulator closely simulates the Sense HAT hardware being attached to your Pi. You can read from the sensors or write to the LED matrix using multiple Python processes, for example.

sense-idle

Write your code in IDLE as before; there are also a number of examples that can be opened from the emulator’s built-in menu. If you then want to port your code to a physical Sense HAT, you just need to change

sense_emu

to

sense_hat

at the top of your program. Reverse this if you’re porting a physical Sense HAT program to the emulator, perhaps from one of our educational resources; this step isn’t required in the web version of the emulator.

sense-emu-prefs

There are a number of preferences that you can adjust to change the behaviour of the emulator, most notably sensor simulation, otherwise known as jitter. This costs some CPU time, and is disabled by default on the low-end Raspberry Pis, but it provides a realistic experience of how the hardware sensors would behave. You’ll see that the values being returned in your code drift according to the known error tolerances of the physical sensors used on the Sense HAT.

This emulator will allow more Raspberry Pi users to participate in future Astro Pi competitions without having to buy a Sense HAT: ideal for the classroom where 15 Sense HATs may be beyond the budget.

So, where do you start? If you’re new to the Sense HAT, you can just copy and paste many of the code examples from our educational resources, like this one. You can also check out our e-book Sense HAT Essentials. For a complete list of all the functions you can use, have a look at the Sense HAT API reference here.

You can even install this emulator on other types of Linux desktop, such as Ubuntu! For more information on how to do this, please visit the emulator documentation pages here.

The post Desktop Sense HAT emulator appeared first on Raspberry Pi.

Sense HAT emulator

Post Syndicated from David Honess original https://www.raspberrypi.org/blog/sense-hat-emulator/

Over the last few months, we’ve been working with US-based startup Trinket to develop a web-based emulator for the Sense HAT, the multipurpose add-on board for the Raspberry Pi which is also the core component of the Astro Pi units on the International Space Station. We wanted to provide a unique, free learning resource that brings the excitement of programming our space-qualified hardware to students, teachers, and others all over the world.

We’re delighted to announce its release today, and you can try it for yourself right now. Click the Run button below and see what happens!

trinket-logo

The emulator will allow more people to participate in future Astro Pi competitions – you’ll be able to join in without needing to own a Raspberry Pi computer or a Sense HAT.

British ESA Astronaut Tim Peake with an Astro Pi unit on the International Space Station

British ESA Astronaut Tim Peake with the Astro Pi. Image credit ESA

The new emulator builds on Trinket’s existing Python-in-browser platform, and provides the following features:

  • Virtual Sense HAT with environmental controls and joystick input
  • Full Python syntax highlighting
  • Contextual auto-complete
  • Intuitive error reporting and highlighting
  • Image upload
  • HTML page embedding
  • Social media integration
  • Project sharing via direct URL
  • Project download as zip (for moving to Raspberry Pi)
  • All major browsers supported

sense_hat_emu

The Sense HAT has temperature, pressure and humidity sensors, and can change its behaviour according to the values they report. The Sense HAT emulator has sliders you can move to change these values, so you can test how your code responds to environmental variables.

Part of a screenshot of the Astro Pi emulator, showing three silders with buttons that can be dragged to change the temperature, pressure and humidity that the virtual Sense HAT's sensors are reporting

You can move the sliders to change what the sensors are reporting

Code written in this emulator is directly portable to a physical Raspberry Pi with a Sense HAT without modification. This means any code you write can be run by the Astro Pi units on board the ISS! It is our hope that, within the next 12 months, code that has been written in the emulator will run in space. Look out for news on this, coming soon on the Astro Pi site!

We owe huge thanks to Trinket, who have been wonderful partners in this project. The development work has been completed in just over two months, and has been a huge collaborative effort from the start. The software relies heavily on open-source technology and a global community of developers who are committed to making the power of code more accessible to students.

A closed group of beta testers, made up of previous Astro Pi participants and Code Club champions, has been putting the emulator through its paces over recent weeks. We’re proud to say that we’ve just had a bug-free open beta over the weekend, and now we’re looking forward to seeing it used as widely as possible.

So, where do you start? If you’re new to the Sense HAT, you can just copy and paste a lot of the code examples from our educational resources like this one. You can also check out our e-book Sense HAT Essentials. For a complete list of all the functions you can use, have a look at the Sense HAT API reference here; please note that the IMU (movement-sensing) functions will be supported in a future update. Head over to the main Sense HAT emulator site to see loads of other cool examples of what’s possible. Flappy LED, anyone?

Don’t forget to share your projects!

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Color-Code Your AWS OpsWorks Stacks for Better Instance and Resource Tracking

Post Syndicated from Daniel Huesch original https://aws.amazon.com/blogs/devops/color-code-your-aws-opsworks-stacks-for-better-instance-and-resource-tracking/

AWS OpsWorks provides options for organizing your Amazon EC2 instances and other AWS resources. There are stacks to group related resources and isolate them from each other; layers to group instances with similar roles; and apps to organize software deployments. Each has a name to help you keep track of them.

Because it can be difficult to see if the instance you’re working on belongs to the right stack (for example, an integration or production stack) just by looking at the host name, OpsWorks provides a simple, user-defined attribute that you can use to color-code your stacks. For example, some customers use red for their production stacks. Others apply different colors to correspond to the regions in which the stacks are operating.

A stack color is simply a visual indicator to assist you while you’re working in the console. In those cases when you need to sign in to an instance (for auditing, for example, or to check log files or restart a process), it can be difficult to immediately detect when you have signed in to an instance on the wrong stack.

When you add a small, custom recipe to the setup lifecycle event, however, you can reuse the stack color for the shell prompt. Most modern terminal emulators support a 256-color mode. Changing the color of the prompt is simple.

The following code can be used to change the color of the shell prompt:

colors/recipes/default.rb

stack = search("aws_opsworks_stack").first
match = stack["color"].match(/rgb((d+), (d+), (d+))/)
r, g, b = match[1..3].map { |i| (5 * i.to_f / 255).round }

template "/etc/profile.d/opsworks-color-prompt.sh" do
  source "opsworks-color-prompt.sh.erb"
  variables(:color => 16 + b + g * 6 + 36 * r)
end

colors/templates/default/opsworks-color-prompt.sh.erb

if [ -n "$PS1" ]; then
  PS1="33[38;5;<%= @color %>m[[email protected] W]\$33[0m "
fi

You can use this with Chef 12, this custom cookbook, the latest Amazon Linux AMI, and Bash. You may have to adapt the cookbook for other operating systems and shells.

The stack color is not the only information you can include in the prompt. You can also add the stack and layer names of your instances to the prompt:

We invite you to try color-coding your stacks. If you have questions or other feedback, let us know in the comments.