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�C Provides Wireless Keypad Control: 10/08/98 EDN-Design
Ideas |
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4 Bit �P's a / D Converter Decodes Keypad's Inputs: 10/13/94
EDN-Design Ideas |
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4 Digit Keypad: |
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Alarm Control keypad: |
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Decimal to BCD Convertor: This circuit will provide an
output in Binary Coded Decimal from any of the input switches.
The input switches may be expanded to 16 switches, providing a
Hexadecimal to BCD conversion. |
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Electronic Keypad: |
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Four Digit Keypad: |
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Key Reading Circuit Saves I/O Pins: 03/06/03 EDN-Design
Ideas / PDF contains multiple circuits - scroll to find this
circuit |
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Keypad Encoder Commands Tape Transport: 09/02/96 EDN-Design
Ideas |
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Keypad sequence activates relay: 10/12/00 EDN-Design Ideas /
PDF contains multiple circuits - scroll to find this circuit
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Low Power Keypad Consumes only 100 NA : 01/24/02 EDN-Design
Ideas / Often in the use of products with keypads, one or more
keys become "stuck" or are being pressed.
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Low power keypad consumes only 100 nA: 01/24/2002 EDN -
Design Ideas / Often in the use of products with keypads, one or
more keys become "stuck" or are being pressed. For example, a
cell phone in the bottom of a purse or in a hip pocket could
have one or more of its keys inadvertently pressed and held down
for a considerable period. Depending on the circuit design and
implementation of the keypad interface, this condition could
cause excess current to flow,... . |
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Novel idea implements low cost keyboard: 04/03/03 EDN-Design
Ideas / Many applications that use a microcontroller also use a
keyboard. If your application uses a relatively powerful
microcontroller, you can use several free I/O pins or an unused
input with an ADC to effect an easy keyboard connection. But, if
the microcontroller in your system has too few free I/O pins and
no on-chip ADC, you can be in trouble... |
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One Pin Keypad Features Low Component Count: 05/26/03
Electronic Design - Ideas for Design / While
current-shunt-monitor ICs like the INA168 can be connected to
current-shunt resistors at supply voltages of up to 60 V, the
circuit shown in the figure allows current sensing at even
higher voltages.... |
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OnePin Keypad Interface Conserves Battery Power : 11/11/02
Electronic Design - Ideas for Design / This idea builds on a
previous IFD, "Connect Any Keypad With Any Microcontroller Using
Only One Pin" (electronic design, May 1, 1998, p. 126), where a
555 timer connects a keypad switch matrix to a microprocessor.
The timer converts a... |
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PIC Based Keyboard Emulator: |
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RS232C Serial Port Scans Remote Keypad: 12/04/97 EDN-Design
Ideas |
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Security Circuit Eschews Sophistication: 05/26/94 EDN-Design
Ideas |
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X Y Keypad uses �C's Serial Port: 10/10/96 EDN-Design Ideas |
