In 2013 the dean of an Ethiopian university addressed Maker Faire Hannover and outlined one of his concerns; that the high price of developed-world textbooks was holding back the cause of education for universities such as his own in developing countries. He was there to ask for help from the maker community to solve his problem, and a group of his audience took up the challenge to create an affordable and accessible automatic book scanner.
Their scanner builds on the work of Google engineer [Dany Qumsiyeh], whose open source linear book scanner turns pages by traversing the opened book over a triangular prismic former such that pages are turned by vacuum as they pass over carefully designed slots in its surface. Their modification replaces the vacuum with the Coandă effect, to more gently tease open each page and it is hoped reduce the chance of damaging the volumes being scanned.
The whole machine is controlled by a Raspberry Pi, and the scanning is performed by linear scanning optics, sensors, and electronics taken from flatbed scanners.
An important design goal of the project was to ensure that the scanner could be built without special tools or expertise that might be difficult to find in a developing country, as well as that it should be as inexpensive as possible. The frame of the machine is off-the-shelf extruded aluminium, and the body is acrylic sheet which can be cut to shape with a hand saw if necessary. It is estimated that the device will cost in the region of 500 Euros (about $568) to build.
Writing from the perspective of having been peripherally involved in a professional book scanning operation at a large publisher the benefits of this machine are immediately apparent. Removing the binding and automatically scanning each page as an individual sheet produces a very fast and high quality result, but by its very nature damages the volume being scanned. This machine promises to deliver a solution to the problem of book scanning that is considerably less intrusive.
It is also worth noting that the project does not address any copyright issues that might arise from scanning commercially published textbooks, though this is more of a concern for the end user in terms of what they scan with it than it is for the maker.
There’s a reason that the bog-standard serial port will never die. It’s just so robust and simple. When you need a console that will absolutely work with minimal software and hardware, UART is the way to go. Because of this, UART hacks abound. Here’s a new one to us, and a challenge to our readers.
[Tiziano Bacocco] decided to use UART signals as a type of PWM to create audio. That’s right, he’s plugging the serial TX line straight into a speaker. This gives you eight possible PWM output voltage levels. The trick is using some Python code (using the awesome pyserial module) to down-quantize the audio data to fit these eight possible values and then push them out at the correct sampling rate. ffmpeg is used to pre-process the files.
There are a number of ways to control an automobile without using the pedals, and sometimes even without using the steering wheel. Most commonly these alternative control mechanisms are installed in vehicles whose owners are disabled in some way, but [Anurag] has taken this idea of alternative control one step further. He has built a car that can be driven by hand gestures alone.
On a remote controlled car, a Raspberry Pi 2 was installed that handles processing and communication. A wireless network is created on the Pi, and a laptop connects to the Pi over the network. The web camera on the laptop regularly captures frames at 15 fps to check for the driver’s hand gestures. The image is converted to gray scale, thresholded, contours are obtained, and the centroid and farthest points are obtained.
After some calculations are done, a movement decision is taken. The decision is passed to the Pi, which in turn, passed that to the internal chip of the car. All of the code is available on the project’s github page. [Anurag] hopes that this can be scaled up to full sized cars in the future. We’ve seen gesture-based remote controls before that rely on Sonar sensors, so it’s interesting to see one that relies strictly on image processing.
[TK] is a retro computer enthusiast who’s had some difficulty locating a joystick for his trusty Amiga 500. New ‘sticks are expensive, and battered survivors from the 80s go for more than they should.
Happily these old controllers were simple devices, having only five control lines for the four directions and a fire button which were active low. [TK] therefore cast around the available components and decided to craft his own controller from a numerical keypad.
Numerical keypads may be ubiquitous, but they’re not the perfect choice for a joypad. Instead of individual switches, they are wired as a matrix. [TK]’s controller works within that constraint without butchering the keypad PCB, though his layout has the left and right buttons below the up and down buttons. Looking at the schematic we wonder whether the 4-5-6 and 7-8-9 rows could be transposed , though joypad layout is probably a matter of personal choice.
Making the controller was a simple case of wiring the pad to a 9-pin D socket in the correct order, and plugging it into the Commodore. He reports that it’s comfortable to use and better than some of the lower-quality joysticks that were on the market back in the day. Veterans of Amiga gaming will understand that sentiment, there were some truly shocking offerings to be had at the time.
We’ve been scratching our heads about the various voice-recognition solutions out there. What would you really want to use one for? Turning off the lights in your bedroom without getting up? Sure, it has some 2001: A Space Odyssey flare flair, but frankly we’ve already got a remote control for that. The best justification for voice control, in our mind, is controlling something while your hands or eyes are already busy.
Dedicated pedal switches for your computer can be really expensive. Keyboards on the other hand, despite having way more buttons, are dirt cheap! What if you could use a keyboard to build a pedal board? This hack is so simple, it’s almost ingenious.
[Shrodingers_Cat] took one of his spare keyboards, a rather nice Logitech G510 gaming keyboard, and pulled all the keys out except for four. You can do this with a flat head screwdriver quite easily — it’s also rather satisfying sending keys flying with each flick of the blade.
He then cut up some spare DVD cases he had, and turned them into pedal covers. They’re actually just nested inside the keyboard — he added some electrical tape to make sure they stayed in place and put it under his desk for the first test — it works great!
For his final project at the Copenhagen Institute of Interaction Design, [Andreas Refsgaard] decided to make something that matters : a system that allows anyone to control a musical instrument using only their eyes and facial expressions. Someone should enter this into a certain contest that’s running…
Dubbed the Eye Conductor, [Andreas] has created a highly customizable system that allows for a control interface that can be operated using only your eyes, and some facial expressions. Designed with the intent to allow everyone to enjoy playing music, [Andreas] user test the system at schools, housing communities for people with physical disabilities, and anyone he could find in a wheel chair. His intent is to continue the project so that all people can enjoy playing music.
The system is open, designed for inclusion and can be customised to fit the physical abilities of whoever is using it.