Handy Tech Galixa Piezo

This Galixa Piezo is based on the Texas Instruments Galaxy 40x and added a 10-cell braille display to the natural voice speech output of the Galixa Speech.

Numerical data on the display panel can be spoken digit by digit or as a complete number. It speaks all key functions: e.g. when the [SIN] key is pressed the calculator says "Sine"; these announcements can be repeated. It also has a built-in clock and alarm function. The volume can be adjusted using a knob.

The language of the Galixa Speech could be chosen between:

The Galixa Piezo provides like its sibling Galixa Speech not only a built-in loudspeaker and a headphone jack but even a 10-cell refreshable Braille display. Mr. Schoenherr invented already in 1975 the first generation of a Braille cell based on small pins pushed by electro-magnets and developed the Braillotron calculator based on the Texas Instruments TI-2550 II. Read more about the refreshable Braille display and Louis Braille.

Dismantling the Galixa Piezo reveals a complete different design of the refreshable Braille cells compared to the original approach. The upper shell of the base station holds once again the calculator, provides a connection to the custom specific electronics in the bottom shell, holds a loudspeaker and a tiny assembly with 10 Braille cell modules. 

Instead the six dots of the original design these cells use now eight dots. The cells are manufactured by Metec AG, Stuttgart - the world leader of Braille actuator cells for display applications. They supply their products to OEM manufacturers of Braille displays in fifteen countries worldwide including the US, China and all major Braille display manufacturers in Europe. 

Already in 1990 Metec developed the first European piezo-electric Braille actuator. Instead of the small magnetic pins lifted by small electro-magnets this innovative designs uses small piezo actuators of the bending type. Simply by providing a high voltage of about 200V DC the piezo elements bend a little and push the plastic parts towards the finger tip of the vision impaired people.

The interface of the Braille actuator cells is quite simple, an ASIC on each module implements a shift-register with 8 outputs representing the 8 pins. The driver voltage of the piezo actuators is switched with some discrete transistors. The ten cells of the Galixa Piezo are simply connected in a daisy-chain manner to the main electronics developed by EHG Handy Tech Elektronik GmbH .

Metec purchased two US based Braille actuator cell manufacturers (Telesensory, and United Braille) in 1998, moving their production to Germany. Metec will, of course, be involved in the cell actuator development and software for graphic tactile display.

Another approach to solve the communication with vison impaired people could be found in talking calculators like the TI-66 Calcu-Talk and the Orbit TI-34. 

If you have additions to the above article please email: joerg@datamath.org.

© Joerg Woerner, September 29, 2002. No reprints without written permission.