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ST7 KEYPAD DECODING TECHNIQUES, IMPLEMENTING WAKE-UP ON KEYSTROKE

You have to press the chosen key at least 0.5 to 1 second depending on which key you

choose (table read from keypad_top to keypad). The faster the key is read into the table, the

faster it will be decoded and the faster the result will be sent on LEDS.

The keypad code is in the file constant.asm as follows:

.keypad

DC.B

$0E,$0E,$1

;PC0 PA0

DC.B

$0E,$0D,$2

;PC0 PA1

DC.B

$0E,$0B,$3

;PC0 PA2

DC.B

$0E,$07,$F

;PC0 PA3

DC.B

$0D,$0E,$4

;PC1 PA0

DC.B

$0D,$0D,$5

;PC1 PA1

DC.B

$0D,$0B,$6

;PC1 PA2

DC.B

$0D,$07,$E

;PC1 PA3

DC.B

$0B,$0E,$7

;PC2 PA0

DC.B

$0B,$0D,$8

;PC2 PA1

DC.B

$0B,$0B,$9

;PC2 PA2

DC.B

$0B,$07,$D

;PC2 PA3

DC.B

$07,$0E,$A

;PC3 PA0

DC.B

$07,$0D,$0

;PC3 PA1

DC.B

$07,$0B,$B

;PC3 PA2

keypad_top

DC.B

$07,$07,$C

;PC3 PA3