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Two wire 4 by 4 key keyboard interface saves power - 08/17/06 EDN Design Idea Resistor matrix and microcontroller encode keypad - You can use a
microcontroller that includes an ADC to design a two-wire-plus-ground keyboard interface. For example, you can
use a resistive voltage divider to identify a. . . [by Stefano Salvatori, University of Rome, Rome, Italy, and
Gabriele Di Nucci, EngSistemi, Rome, Italy] |
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Two-wire, four-by-four-key keyboard interface saves
- 08/17/06 EDN Design Idea You can use a microcontroller that includes an ADC
to design a two-wire-plus ground keyboard interface. For example, you can use a resistive voltage divider to
identify a pressed key (Reference 1). A microcontroller€™s integrated . . . [by Stefano Salvatori, University of
Rome, Rome, Italy, and Gabriele Di Nucci, EngSistemi, Rome, Italy]
Using a Keyboard with the Microchip Graphics Library - AN1227 - Technology Inc. . . . [Microchip App Note - last updated on 28-Mar-10]
Water & vandal-proof keypad uses piezoelectric disc as sensor and buzzer - 04/21/14 EDN Design Idea An ingenious and low-cost method to create a rugged “UI”. This
design was done to get a sealed keypad for very wet environments (in my particular case, showers for swimming
pools). The keypad needed to be able to detect slight pressure on a stainless steel plate 0. 4mm thick. Apart
from water protection, the solution offers an esthetical finish, as the user side is absolutely flat, with
nothing visible other than the silkscreened print. Another advantage of this type of keypad is that it is
vandal-proof. . . [by Francesc Casanellas]
White LED driver backlights LCD and keypad - 11/13/03 EDN
Design Idea Designers widely use white LEDs to backlight color LCDs and keypads in handheld devices, such as
cell phones, MP3 players, GPS navigators, and PDAs. Their spectrum and brightness represent near-ideal light
sources. One possible con. . . [by Fabien Franc, Catalyst Semiconductor, Sunnyvale, CA]
White LED driver provides 64 step logarithmic dimming - 10-Jun-04 EDN Design Idea The circuit of Figure 1 is designed for portable-power
applications that require white LEDs with adjustable, logarithmic dimming levels. The circuit drives as many as
four white LEDs from a 3.3V source and adjusts the total LED cur. . . [by William Hadden, Maxim Integrated
Products, Sunnyvale, CA]
Wired
USB Keyboard - STMicroelectronics-Application. . .
XY Keypad uses
µC's Serial Port - 10/10/96 EDN Design Idea Interfacing
an X-Y keypad to a microcontroller usually uses a parallel port of 8 bits or more. But with the circuit shown in
Figure 1, a more efficient interface using a microcontroller's serial port reduces the number of connect. . .
[by James Mears, National Semiconductor, Tacoma, WA]
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