Running Easel On Raspberry Pi

Sacha De’Angeli uploaded Easel on the Raspberry Pi turning it into a CAD workstation.

Sacha De’Angeli uploaded Easel on the Raspberry Pi turning it into a CAD workstation.


The Raspberry Pi has been used for everything from a stand-alone PC to an arcade machine emulator but could it be used to run as a CAD workstation? The answer to that question used to be no, however Sacha De’Angeli over at Simple Switch Labs was able to turn that answer into a yes with the help of Raspberry Pi.

The secret to his success lies with Inventables’ Easel cloud-based 2D/3D CAD software, which does most of the heavy lifting for design and fabrication projects. Sacha loaded the Easel app on his Raspberry Pi (model B) running Raspian and the Epiphany browser to grab 2D and 3D files, turning them into g-code. That code is then sent to an Arduino (via USB) that’s running the GRBL CNC milling controller, which provides the needed instructions to run his Shapeoko milling machine. Suffice it to say, there’s no longer a need to use an expensive laptop or desktop to power a Shapeoko, which is notorious for producing dust when carving out materials. To read a complete walkthrough on how Sacha built his setup head on over to the Simple Switch blog.

Programmer Revives Teletype With Raspberry Pi

Sudo Bob’s Teletype (image courtesy of Sudo Bob)

Sudo Bob’s Teletype (image courtesy of Sudo Bob)


If you were around before desktop computers were commonplace in-home, then you probably remember the teletype. Well folks, the old school communication device is making a comeback, thanks to the efforts of a self-proclaimed nerd by the name of Robert Coggeshall (co-programmer of sudo), and of course, the popular Raspberry-Pi SBC.

Teletype (image courtesy of Sudo Bob)

Teletype (image courtesy of Sudo Bob)


Teletypes fell off the radar with the advent of the fax machine and personal computer, but for some (like Sudo Bob), having retro devices that are much more difficult to use than the newer gadgets brings a certain level of nostalgia. It’s like rushing home to use your corded home phone, even though you have a cell phone, just because you still like wrapping that curly cord all around the living room furniture. Ah. It gets you every time.

Regardless, Sudo Bob resurrected the teletype just because he can. He snagged a spare teletype from another 70s kid from the NYC Resistor crew at the 2013 Maker Faire and the rest is history. Oh glorious teletype, you have returned!

Diagram of Bob's RPi and relay board (image courtesy of Sudo Bob)

Schematic for wire the connections of Bob’s RPi and relay board (image courtesy of Sudo Bob)


With a 2-Channel Relay Module, Raspberry-Pi, N-Channel Mosfet, 200 OHM 1 Watt Resistor, 24VDC Wall Wart, F<>F Rainbow Jumper Wiring and a little rewiring, the 50-year-old device has been fully restored. Bob also used the Raspbian Wheezy distro and ran the Ras Pi headless for coding, but use your own discretion if you’re building your own.

The complete package that powers the Teletype (image courtesy of Sudo Bob)

The complete package that powers the Teletype (image courtesy of Sudo Bob)


If you’ve got an old teletype you’re looking to restore as well, check out Sudo Bob’s blog for the full specs and building process for making your own.


Raspberry Pi Model A+ Revealed: Smaller and Just $20


Update: We’ve got them in the Maker Shed!   This morning, the Raspberry Pi Foundation took the wraps off of their newest creation, the Raspberry Pi Model A+. Just as the original Model A was a stripped-down version of the Model B, the new A+ inherits the many improvements from the Model B+, but in a smaller size and with fewer features. Available for purchase starting today and pegged at a mere $20, the Model A+ is now cheapest Raspberry Pi that you can buy.

The A+ has a lot of the same specs as its predecessor, the model A. It’s the same Broadcom BCM2835 system on a chip (SoC) with 256 megabytes of RAM. But unlike the model A, it has a much nicer look and feel. No longer are there unpopulated parts of the PCB, which means that its overall footprint is smaller and it’s much lighter. Like the improvements brought with the Model B+, it has the expanded 40 pin breakout, takes MicroSD cards, and has rounded corners with mounting holes in each corner. In fact, you may notice that the mounting holes are aligned with the Model B+ mounting holes. Not only will this make swapping the B+ for an A+ rather easy, but also HAT expansion boards will be compatible with the A+ in addition to the B+.

“When we announced Raspberry Pi back in 2011, the idea of producing an ‘ARM GNU/Linux box for $25’ seemed ambitious, so it’s pretty mind-bending to be able to knock another $5 off the cost while continuing to build it here in the UK, at the same Sony factory in South Wales we use to manufacture the Model B+,” said Eben Upton in the announcement post blog post.


Thanks to the Raspberry Pi Foundation, I’ve had a Model A+ to experiment with over the past couple weeks. My first impression was how remarkably small and light it is. With no Ethernet port and only a single USB port, it has a very slim profile. That, combined with its smaller PCB footprint means its overall dimensions and weight are greatly reduced. The difference in size is striking. Since many Raspberry Pi projects entail putting the board in some tight spots, the A+ will be useful in cases when the B+ is just too big. I should note that although the Model A+ can fit into an Altoids tin, the board doesn’t quite lie flat inside.

The second significant feature is its price tag. At $20, it’s amazingly affordable and priced very competitively against microcontroller boards and single board computers that are available to makers now. It’s no surprise since Raspberry Pi has always been a leader in affordability. After all, the mission of the non-profit foundation is to get these boards in the hands of young people so that they can learn how computers work and how to program them. By setting the price so low, it removes a big barrier to experimentation with computers.

Booting up the board, it’s everything you’d expect from a Raspberry Pi. Just keep in mind that with 256 megabytes of RAM, the model A+ has half the volatile memory of the B+. (This was also true with the previous generations of both boards.) This means that memory-intensive applications will take a performance hit when compared to a B+. Using the basic tools from the command line and desktop environment, I didn’t notice a ding in performance. Keep in mind that the amount of RAM that’s allocated between the CPU and GPU is adjustable with the raspi-config configuration tool. You may need to make adjustments to optimize the Pi for your application.

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Without the extra components, the Raspberry Pi Model A+ draws about 30% less electrical current than the B+. After booting to the Raspbian login with a USB keyboard and mouse plugged in, the A+ drew about 220 milliamps whereas a B+ with the same setup draws about 310 milliamps. With this power savings, the A+ would make a good choice for battery-powered projects.

It’s no secret that the original Model A hasn’t been a big seller for the Raspberry Pi Foundation. In an interview with John Biggs at Techcrunch Disrupt, Eben Upton said that there was only about 100,000 Model A units sold versus the nearly 4 million sold of the Model B and B+ combined. Perhaps with the lower price, smaller size, and a bunch of “plus” enhancements, the new Model A+ will start to earn its keep in the world.

Stereo Depth Perception with Raspberry Pi


One of the features of the Raspberry Pi Compute Module Development Kit is that the IO board has two camera serial interface connectors. This means that you can connect two of the official (and popular) Raspberry Pi Camera Modules to the board. Argon Design intern David Barker used this enhancement to create a camera capable of depth perception, which requires two separate images and a stereo depth algorithm. Here’s how he explains it:

The algorithm we used is a variant of one which is widely used in video compression. The basic idea is to divide each frame into small blocks and to find the best match with blocks from other frames – this tells us how far the block has moved between the two images. The video version is designed to detect motion, so it tries to match against the previous few frames. Meanwhile, the depth perception version tries to match the left and right camera images against each other, allowing it to measure the parallax between the two images.


David started with some Python code to try out, but translated it into C to speed up the image processing by a factor of over 1,000. He then translated it once again to Assembly for the Raspberry Pi’s GPU… no doubt an impressive feat! Now the process of getting the images from the cameras, processing them to get the depth data, and displaying the results on screen takes around 90 milliseconds, which translates to a respectable 12 frames per second.

For more details on how he accomplished this, check out his case study. [via The Raspberry Pi Blog]

Cat Lover Makes DIY Google Glasses With Raspberry Pi

Nur with his prototype (image courtesy of Nur’s Idea Studio)

Nur with his prototype (image courtesy of Nur’s Idea Studio)


If you’ve been eyeballing the progress of the Google Glasses, wondering when and how you can build your own, never fear – DIY makers are here! Maker Nur, who loves coffee and his cats (have cat ladies lost their flair?), devised a way to create his own smart eye-wear, using Raspberry-Pi and a homemade iOS Air App.

Nur calls the creation Air Glasses. The homemade smart eye-wear relies upon an application he calls the Air App. An Air App is a web-based, micro, push application, which takes the image on an iPhone and projects it onto the glasses, courtesy of Raspberry-Pi and a hotspot connection.

Air Glasses User Interface (image courtesy of Nur’s Idea Studio)

Air Glasses User Interface (image courtesy of Nur’s Idea Studio)


While the only hard supplies needed were sunglass frames, a Raspberry-Pi mini computer, video glasses LCD components and a mobile hotspot connection, mad hacking skills are a must for anyone planning to tackle this project. Only the best software engineers and app developers will make it out without a scratch! Regardless, if you’re up for the challenge, you can save yourself a nice chunk of change by designing smart glasses yourself. Nur’s prototype doesn’t exactly include GPS and X-ray vision, but displaying the time is a good start. Nur may go on to develop more complicated Air Apps for the eye-wear, but only after he spends quality time with the kitties.

Raspberry Pi and Arduino Home Automation

Home automation made easy with the help of Raspberry Pi and Arduino

Home automation made easy with the help of Raspberry Pi and Arduino

Everybody knows that good things happen when you pair a Raspberry Pi with an Arduino, which includes everything from a Star Trek-like tricorder to a kegerator interface. One Instructables user (Electronichamsters) decided to take the boards and design an extensive home automation platform that’s able to monitor just about everything inside and outside of user’s homes.

Instead of using the boards for simple things such as automated blinds or lights, Electronichamsters ‘Uber Home Automation’ platform can monitor for water leaks, loud noises and even alert users when the mail arrives. His design makes use of a series of cheap wireless sensor nodes (PIR, heat, light, sound, etc.) that can be placed anywhere and on anything that needs monitoring. Those nodes relay the data to a wireless gateway and an Ethernet gateway (an Arduino Uno), which in turn sends the data to the Raspberry Pi.

Electronics basic design schematic gives users a rough idea of how the platform works

Electronics basic design schematic gives users a rough idea of how the platform works

The RPi then uploads the data to the internet where users can monitor using their smartphones. It even sends alert emails when something is amiss, allowing users to view the issues through a web cam. The whole setup costs a little over $270, assuming users already own a Raspberry Pi. Those that want to see the build process can head over to Instructables, which has a detailed list of parts and code to get things up and running. Want to know more… head over to project’s Indtructables page.

Ahh... the adhoc project enclosure... It may look crude but this sound sensor is very effective and can be placed anywhere

Ahh… the adhoc project enclosure… It may look crude but this sound sensor is very effective and can be placed anywhere


How-To: Building a Raspberry Pi WiFi Controlled Car


When you don’t like what it is offered, make it yourself. At least that’s what German based maker Ingmar Staple did. When shopping for his niece and nephew, Ingmar was unimpressed with the selection of toys at toy stores. So, he decided to make one of his own. A Raspberry Pi WiFi radio controlled RC car, with a cardboard chassis.



After finishing the project, friends of Ingmar insisted he put together a How-To guide and share it. It’s divided nicely into 12 chapters, and includes lots of great information for building your own RC car. The project uses a short list of tools to build the cardboard part of the car which include glue, a hot glue gun, a carpet knife, scissors, a ruler, a pan, and a circle, and is simple to make.

DIY Game Boy Pocket Using the Raspberry Pi

Don’t be fooled, this isn’t an actual Game Boy but a Raspberry Pi-based Pocket Pi.

Don’t be fooled, this isn’t an actual Game Boy but a Raspberry Pi-based Pocket Pi.

The Game Boy Pocket hit the market back in 1996 and is still popular with fans of the handheld gaming system that they can still be bought today. Yeah, there’s nothing like gaming on a black and white screen, which was better than the pea-green screen of the original Game Boy. Those who are fans of the Pocket but would like to have a color screen and be able to play games from other systems should take a look at Travis Brown’s Pocket Pi.

All of these parts, including the RPi and modified button pad fit nicely inside the Game Boy case.

All of these parts, including the RPi and modified button pad fit nicely inside the Game Boy case.

Travis designed the Pocket Pi by removing the guts from an old Game Boy Pocket and replaced them with a Raspberry Pi SBC running Retro Pi to emulate Game Boy games. To get it to fit correctly, Travis had to modify the case a little bit in order to pack the Pi, 2.5-inch LCD screen, modified Game Boy game pad and battery pack, however it still looks good with all the electronics packed into the small area. The best part is that the Pocket Pi can play games from other platforms as well, including NES, Sega Master System and even Game Gear using the Retro Pi emulator.

PiGRRL Raspberry Pi Game Boy replica with 3D printed case looks suspiciously like the real thing.

PiGRRL Raspberry Pi Game Boy replica with 3D printed case looks suspiciously like the real thing.

Of course, this isn’t the first time someone has made a Raspberry Pi-based Game Boy replica as Make reported on a 3D printed Replica from Adafruit back in July of this year (make it so). In that case, the Game Boy clone made use of a Raspberry Pi, SNES controller and PiTFT mini kit to play emulated games. The kicker was that it could be had in several different colors using a customized 3D printed case. It just goes to show what Nintendo fans are capable of when they want to get their retro gaming on! A video showing the game selection and play can be viewed below. See more about this build through this link.

Raspberry Pi Hardware Discussion: Compute Module, HATs, and Model B+

At MakerCon, I had the pleasure of sitting down with James Adams, the Director of Hardware Engineering for Raspberry Pi. We talked about his role in the design of the Linux single-board computer and the newest hardware. Their new Model B+, the HAT specification, and the Compute Module.

James is also on the team behind Slice, the Compute Module-based media player. In our interview, we covered how the process of developing Slice lead to software and hardware improvements in the Compute Module. Come to World Maker Faire New York this weekend to see a prototype of Slice and check out all the Raspberry Pi projects and programming.