Assistive technologies have a pretty big presence here on Hackaday, and this hack is nothing short of interesting. [kerchoo_22] is working on a hands-free video game controller as a final project for her engineering class and we think it’s worth sharing.
The basic premise of the circuit is pretty simple. She DIY’d a few contact switches using conductive plates made of cardboard, duct tape, and aluminum foil. The output of the switch is read by analog input pins on an Arduino Leonardo. When the switches are off, the analog input pins are pulled HIGH using 1 MegaOhm resistors. But when the user hits their head on one of the four conductive pads, the switch is engaged, and the analog input pins are shorted to ground.
The Arduino Leonardo, having a native USB port, is able to directly emulate a keyboard. Each conductive pad is mapped to a different key press corresponding to different functions within the game. Left, right, shoot, etc. And there you have it, gameplay without using hands or a controller!
Now, it seems as though [kerchoo_22] put an appropriate amount of cushion on the head pads, so there probably isn’t much danger of a concussion. Either way, you can never be too careful.
At the core of any assistive technology is finding a way to do something with whatever abilities the user has available. This can be especially difficult in the case of quadriplegia sufferers, the loss of control of upper and lower limbs caused by spinal cord damage in the cervical region. Quadriplegics can gain some control of their world with a “Sip-and-puff” device, which give the user control via blowing or sucking on a mouthpiece.
A sip-and-puff can make a world of difference to a quadriplegic, but they’re not exactly cheap. So to help out a friend, [Jfieldcap] designed and built an open source sip-and-puff mouse on the cheap. As is best for such devices, the design is simple and robust. The hollow 3D-printed mouthpiece acts as handle for a joystick module , and a length of tubing connects the mouthpiece to a pressure sensor. An Arduino lets the user move his head to position the cursor; hard sips and puffs are interpreted as left and right clicks, while soft mouth pressure is used for scrolling. In conjunction with some of the accessibility tools in modern OSes and personal assistant software like Siri or Cortana, the sip-and-puff opens up the online world, and for all of $50 in material.
We’re impressed by the effort and the results, but we worry that the standard PLA used for the mouthpiece won’t stand up to the cleaning it’ll need. Of course, printing extra mouthpieces is easy, but since it’s going to be in contact with the mouth, perhaps a review of food-safe 3D-printing is in order.
For most of us, our touch-screen smartphones have become an indispensable accessory. Without thinking we tap and swipe our way through our digital existence, the promise of ubiquitous truly portable computing has finally been delivered.
Smartphones present a problem though to some people with physical impairments. A touchscreen requires manual dexterity on a scale we able-bodied people take for granted, but remains a useless glass slab to someone unable to use their arms.
LipSync is a project that aims to address the problem of smartphone usage for one such group, quadriplegic people. It’s a mouth-operated joystick for the phone’s on-screen cursor, with sip-and-puff vacuum control for simulating actions such as screen taps and the back button.
To the smartphone itself, the device appears as a standard Bluetooth pointing device, while at its business end the joystick and pressure sensor both interface to a Bluetooth module through an Arduino Micro. The EAGLE board and schematic files are available on the project’s hackaday.io page linked above, and there is a GitHub repository for the code.
Technology is such a part of our lives these days, and it’s great to see projects like this bridge the usability gaps for everyone. Needless to say, it’s a perfect candidate for the Assistive Technology round of the Hackaday Prize.
A sip-and-puff device is an assistive technology used by people who cannot use their hands. Being a quasi-medical device, you can imagine this technology is extremely expensive, incapable of being modified, and basically a black box that can’t do anything except what it was designed for. For his Hackaday Prize entry, [Jason] is building his own sip-and-puff interface that’s cheaper and more capable than the available commercial versions.
Sip-and-puff devices can be mapped to control a wheelchair, click a mouse, or press a key on a keyboard. You can do a lot with USB, so for this open sip-and-puff device, [Jason] is using the ever-popular ATmega32U4 microcontroller.
USB is only one part of the problem, and to measure the sips and puffs of air through a plastic hose, [Jason] is using a pressure sensor from Freescale/NXP. While this is very similar to what would be found in the off-the-shelf version of a sip-and-puff device, it’s rather hard to interface with. The current version of the board is using an instrument amplifier, and the mechanical connection between the pressure sensor and the board is slightly bizarre. [Jason] has a few ideas for a better sensor, and for the rest of the Hackaday Prize he’s going to work on redesigning this device with simplicity in mind.