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TIDE and Tibbo BASIC User Manual
©2000-2008 Tibbo Technology Inc.
, all intended scan lines should be
configured as outputs, and all return lines -- as inputs (see
,
).
Scan lines can optionally perform a double duty and drive LEDs. One such LED can
be connected to each scan line, preferably through a buffer, as shown on the
drawing below. These LEDs can be used for any purpose you desire -- and this
purpose can be completely unrelated to the keypad itself.
If the LED is connected as shown on the drawing, you need to set the
corresponding I/O line LOW in order to turn this LED on. Each time the kp. object
is to scan the keypad for pressed keys -- and this happens every 10ms -- it will
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