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KEYPAD

4 KEYPAD

The keypad used is a 4x4 matrixed keypad. Rows are connected to pins configured as inputs

with pull-up. So the initial state of these pins are a high level (1). When a key is pressed, a low

level is applied to the corresponding pin. For this reason, the keypad is coded as follows:

Table 1. Key values

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.

KEY

row

value

column

value

KEY

row

value

column

value

1

0x0E

0x0E

7

0x0B

0x0E

2

0x0E

0x0D

8

0x0B

0x0D

3

0x0E

0x0B

9

0x0B

0x0B

F

0x0E

0x07

D

0x0B

0x07

4

0x0D

0x0E

A

0x07

0x0E

5

0x0D

0x0D

0

0x07

0x0D

6

0x0D

0x0B

B

0x07

0x0B

E

0x0D

0x07

C

0x07

0x07

12

3

F

45

6

E

7

8

9

D

A

0

B

C

PC0

PC1

PC2

PC3

PA0

PA1

PA2

PA3