DataTouch - an tactile text output device

MOTIVATION
One of the themes I've become interested in lately is screen-free computing. Mobile devices, and others designed to minimize cognitive load can take advantage of channels of human sensory perception other than the visual system. Since tactile is an under-used channel of information transmission I decided to design a system to convey messages entirely by touch.

OVERVIEW
DataTouch is a tactile text renderer. When it detects a hand resting on top of it, the machine launches itno action, pulsing information onto the fingertips via its 5 strategically-placed solenoids. Using a binary encoding for a numerical representation of the alphabet (A = 1, B = 2, etc..), datatouch pulses out a different pattern for each letter of the alphabet. Using DataTouch proficiently requires the memorization of the binary representation of the numbers from 1-26. Attached to an Internet-connected computer, DataTouch facilitates online chatting without sight or sound!

FABRICATION
Here are the parts of the device, grouped according to the themes we studied in MAS863:

	Design Tools I used CorelDraw extensively for 2D modeling of the acrylic pieces. (didn't use any 3D modeling tools for this project)
	Laser, waterjet, NC Knife cutting Lasercut all of the acrylic for the surrounding box (most is press-fit, and connectors are epoxied/bolted in place)
	Microcontroller programming yes. Programmed in C for the PICF876 to enable the behavior of the box. Pic was reading digital sensor data from the IR switch, driving the solenoids, and doing bi-directional serial communication with my PC.
	Circuit Design I designed a digital circuit to connect the microcontroller, IR sensor, solenoids, max233 chip and assorted ports.
	3D printing/NC Machining Although I had experimented with making mounting brackets for the solenoids using the 3D printer, my final design used lasercut acrylic.
	PCB Design and Fab I made 5 little solenoid driver boards with the modela which are mounted to the inner walls of the box.
	Forming and Joining Epoxy holds some of the IO ports in place. Lock-washers are keeping the bolts from un-screwing. Zip-ties also came in handy to give the springs a little more slack!
	Sensors, actuators and displays An IR sensor tells the device when there's a hand on top of it. Solenoids pulse the user's fingertips with data.
	Wired and wireless communication I hooked up a Max233 chip for my serial communication with the connected computer. Also hooked up a PS/2 port for keyboard connectivity, although this feature didn't make it in for demo-day. (I had this working on its own board earlier, but for some reason the data line was going between 2 and 5 volts rather than 0 and 5 after I integrated all of the pieces..) And I've been experimenting with MIDI during this term.

Some extra photos

• The solenoid boards, from the bottom
• The solenoid boards, from the top
• The solenoids
• Some lego wheel assemblies that helped the top of the device spring back after the hand is removed
• Epoxy holds these little washers in place
• That's my hand.. and I'm apparently doing some testing
• All debugged-out at the 11th hour

Back to main page