Eye-Controlled Wheelchair Advances from Talented Teenage Hackers

[Myrijam Stoetzer] and her friend [Paul Foltin], 14 and 15 years old kids from Duisburg, Germany are working on a eye movement controller wheel chair. They were inspired by the Eyewriter Project which we’ve been following for a long time. Eyewriter was built for Tony Quan a.k.a Tempt1 by his friends. In 2003, Tempt1 was diagnosed with the degenerative nerve disorder ALS  and is now fully paralyzed except for his eyes, but has been able to use the EyeWriter to continue his art.

This is their first big leap moving up from Lego Mindstorms. The eye tracker part consists of a safety glass frame, a regular webcam, and IR SMD LEDs. They removed the IR blocking filter from the webcam to make it work in all lighting conditions. The image processing is handled by an Odroid U3 – a compact, low cost ARM Quad Core SBC capable of running Ubuntu, Android, and other Linux OS systems. They initially tried the Raspberry Pi which managed to do just about 3fps, compared to 13~15fps from the Odroid. The code is written in Python and uses OpenCV libraries. They are learning Python on the go. An Arduino is used to control the motor via an H-bridge controller, and also to calibrate the eye tracker. Potentiometers connected to the Arduino’s analog ports allow adjusting the tracker to individual requirements.

The web cam video stream is filtered to obtain the pupil position, and this is compared to four presets for forward, reverse, left and right. The presets can be adjusted using the potentiometers. An enable switch, manually activated at present is used to ensure the wheel chair moves only when commanded. Their plan is to later replace this switch with tongue activation or maybe cheek muscle twitch detection.

First tests were on a small mockup robotic platform. After winning a local competition, they bought a second-hand wheel chair and started all over again. This time, they tried the Raspberry Pi 2 model B, and it was able to work at about 8~9fps. Not as well as the Odroid, but at half the cost, it seemed like a workable solution since their aim is to make it as cheap as possible. They would appreciate receiving any help to improve the performance – maybe improving their code or utilising all the four cores more efficiently. For the bigger wheelchair, they used recycled car windshield wiper motors and some relays to switch them. They also used a 3D printer to print an enclosure for the camera and wheels to help turn the wheelchair. Further details are also available on [Myrijam]’s blog. They documented their build (German, pdf) and have their sights set on the German National Science Fair. The team is working on English translation of the documentation and will release all design files and source code under a CC by NC license soon.

Hacklet 46 – ODROID Projects

It seems you can’t mention the Raspberry Pi these days without someone bringing up the Odroid. Named after the combination of Open and Android, the current Odroid brand covers several boards – the U3, the UX3 with its 2 Ghz Samsung quad-core processor, and the C1, which is directly aimed at our favorite fruit pie computer. With all this popularity, one would expect a few awesome projects based around the Odroid machines, and you’d be right! This week’s Hacklet is all about projects using the Odroid on Hackaday.io!

Robbie jrWe start with [herrkami] and CRONUS. Cronus started life as a Robbie Junior, Radio Shack’s re-branded version of Takara Tomy’s Omnibot Jr.  [herrkami] has upgraded Cronus’ brain with an Odroid U3. Cronus can now reliably respond to voice commands thanks to a little help from Google’s speech recognition engine and the accompanying Python API. Cronus is rather conversational as well, all due to the AIML framework. [herrkami] hopes to cut the cord (or WiFi link) once he gets CMU sphinx up and running. Some of [herrkami’s] best work is in his cardboard templates to create a mechanism for turning Cronus’ head. These are some pretty sweet updates for a 1986 vintage robot!

 

serverNext up is [tlankford01] with Linux Tutorial: Odroid U3 Server w/ Seafile Cloud. [tlankford01] walks us through setting up a file server using the Odroid, a 16 Gigabyte EMMC card, and a hard drive to hold the files. As one might expect, this tutorial covers a LAMP (Linux, Apache, MySQL, PHP) server stack. The 9 project logs take us from a bare microSD card to a full server. The Odroid’s 2 Gigabytes of ram are put to good use running the open source Seafile cloud server package. Tutorials like this deserve lots of love from the Hackaday.io community. Sometimes you just need to get a solid file server up and running. When that happens, this type of project is often just what the doctor ordered! So don’t be a lurker, head over to [tlankford01]’s page and give him a skull!

 

touch[Victor] gets us one step closer to an Odroid tablet with the HDMI touchscreen. HDMI touchscreen is a project to connect a 7″ 1024 x 600 LCD with a capacitive touchscreen to HDMI based computers. The heart of the project is Texas Instrument’s TFP401 panelbus DVI receiver chip. This chip makes interfacing LCD screens to HDMI or DVI video cards (almost) painless. There still is a bit of X configuration to do to get things running. [Victor] even got his Odroid running in Android with his custom screen setup. Those of us who have spent time in display an input configuration file limbo know that this is no small feat!

htpcFinally we have [darth_llamah] with Odroid-U3 HTPC. [Darth] raided his junkbox and parts drawers to build a solid home theater PC using the Odroid-U2. The U2 is a bit older than the current U3 models, but all [Darth’s] work should apply to any of the Odroid series. An old Itona case provided the frame for this hack, but it took a lot of custom work with plastic and epoxy to make everything fit. [Darth’s] software stack is the popular OpenELEC Linux build. [Darth] even setup a real “soft” power button using an ATtiny85 connected to USB and s Adafruit’s TrinketHidCombo library.

If you want to see all the Odroid projects in one place, check out our new Odroid projects list!

That’s it for this Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

The Smallest Portable Pi

What do you get when you take an extremely small Raspberry Pi clone and stuff it inside a Game Boy Advance SP? We don’t know what to call it, but it’s probably one of the best portable gaming machines ever made, able to run emulators ranging from the Apple II to playing Quake III natively on a tiny flip-top display.

This isn’t the first time we’ve seen [frostedfires]’ work on a tiny system stuffed into a Game Boy. The initial post on this build over on the bacman forums just covered the basics – getting an Odroid W up and running, and putting Quake III on the tiny display. Now that the build is complete, we can get a look at what it takes to turn a Raspberry Pi clone into one of the smallest portable projects we’ve ever seen.

Using a Raspi clone as the only component in a tiny portable emulation station isn’t possible, so [frostefires] added a few other bits of electronics to make everything work. There’s a joystick from a PSP in there to work as the mouse, a few extra buttons in addition to the stock Game Boy ones, A USB hub, WiFi adapter, speaker and amplifier, a battery and the related charging electronics, and a Teensy 3.1 to handle all the input.

It’s a very impressive build that can run emulators ranging from the Apple II to later generation Nintendo consoles and handhelds (including the Game Boy Advance), but since the HDMI connector is availble on the outside of the case, [frostedfires] can also use this as a tiny, portable media center. Check out the video below to see this Game Boy in action, playing Mario Kart and 1080p video.

Continue reading “The Smallest Portable Pi”

A Raspberry Pi in a Game Boy Advance SP

It’s not the biggest use of a Raspberry Pi, but running emulators for old game systems is by far the most visible use of the Pi. In fact, putting Pis inside old game systems has led to a resurgence of case modding not seen since the heyday of the Mini-ITX craze of the early ‘aughts.

You’d think every possible Pi casemod had been done by now, but [frostedfires] is still raising the bar with a Pi casemod that stuffs a clone of everyone’s favorite credit card sized computer into a Game Boy Advance SP.

[frostedfires] isn’t using a real Raspi from The Foundataion. Instead, he found the Odroid W, a raspi compatible board that’s about half the size of a model B. It still has everything needed to complete the build – analog video out, a reasonable Linux system, and enough processing power to run Quake III. Right now, [frostedfires] has the screen working – that was taken from a car backup camera. Other than that, the only portion of the build left to go is a few buttons.

This is officially the smallest derivative casemod we’ve ever seen. the previous record holder was the still tiny Game Boy Pocket build from last summer. That build required heavy modifications to the Model B board, though, so if you’re aiming for a smaller build, the Odroid is the way to go.

Thanks to the Bacman forums for yet another great build.

A Real Raspberry Pi Clone (Not ‘Inspired By’)

odroid A few years ago, Broadcom had a pretty nice chip – the BCM2835 – that could do 1080 video, had fairly powerful graphics performance, run a *nix at a good click, and was fairly cheap. A Broadcom employee thought, “why don’t we build an educational computer with this” and the Raspberry Pi was born. Since then, Broadcom has kept that chip to themselves, funneling all of them into what has become a very vibrant platform for education, tinkering, and any other project that could use a small Linux board. Recently, Broadcom has started to sell the BCM2835 to anyone who has the cash and from the looks of it, real Raspberry Pi clones are starting to make their way into the marketplace.

Other Raspberry Pi clone boards out there like the Banana Pi and the HummingBoard don’t use the same BCM2835 found in the Raspi and the new Odroid. The new board also has the same 26 pin GPIO expansion socket, and runs the same binaries as the Raspberry P;. It is a clone in every sense, with a slightly different form factor geared towards very tiny, portable, and battery-powered use cases.

Unlike the official Raspberry Pi Compute Module, the Odroid isn’t meant to be used as a system on module, shoved into any product that needs a fast-ish ARM core without needing engineers to actually design a circuit with an ARM. The Odroid is a cut-down, extremely minimalist version of the Raspi, perfect for any project where space is at a premium.

There are a few interesting features included on the Odroid: there’s an on-board battery connector, a real-time clock on the board, and more of the BCM2835 GPIOs are exposed (although not the same ones as the upgraded RPi Model B+). There’s no Ethernet, but odds are if you’re building something that’s battery-powered, you won’t need that anyway.

As far as price goes, you can pick one of these Odroids up for $30 USD, with $9 shipping from South Korea. That’s pretty comparable to the price of a real Raspberry Pi, but if the features in the Odroid are worth it to you, it might be a worthwhile clone.

Autonomous Balloon Popping

Quadcopter drone for popping balloons

Taking on an autonomous vehicle challenge, [Randy] put together this drone which can locate and pop balloons. It’s been assembled for this year’s Sparkfun Autonomous Vehicle Competition, which will challenge entrants to locate and pop 99 luftbaloons red balloons without human intervention.

The main controller for this robot is the Pixhawk, which runs a modified version of the ArduCopter firmware. These modifications enable the Pixhawk to receive commands from an Odroid U3 computer module. The Odroid uses a webcam to take images, and then processes them using OpenCV. It tries to locate large red objects and fly towards them.

The vision processing and control code on the Odroid was developed using MAVProxy and Drone API. This allows for all the custom code to be developed using Python.

The Sparkfun AVC takes place tomorrow — June 21st in Boulder, Colorado. You can still register to spectate for free. We’re hoping [Randy]’s drone is up to the task, and based on the video after the break, it should be able to complete this challenge.

Continue reading “Autonomous Balloon Popping”

Odroid: all the open, none of the contract

The Odroid derives its name from the combination of Open and Android. The hardware is aimed at the portable gaming market and runs Android. The specs are amazing, the device is open and begging you to develop for the platform.

The Samsung S5PC100 System-On-A-Chip provides the device with an ARM Cortex-A8 processor running at 833MHz. The usual suspects are all here, a capacitive touchscreen, accelerometer, SDHC slot, and WiFi. What you usually don’t expect to see is a serial debugger and 720p HD output. But the best part, we get all of this without a 2 year contract or the hardware being locked down as we’re used to with and Android based cell phone.

[Thanks Stillbourne via LinuxDevices]