KeypadRaw

Syntax:

    largevar = KeypadRaw

Command Availability:

Available on all microcontrollers.

Explanation:

This function returns a 16-bit value, in which each bit corresponds to a key on the keypad. If a key is pressed, its bit holds 1; if it is released, its bit holds 0. Because every key gets its own bit, KeypadRaw can detect multiple keys pressed at the same time — unlike KeypadData, which only ever reports one.

This table shows the key that each bit corresponds to:

Bit Key Position (row, col) Common Key Symbol

15

1,1

1

14

1,2

2

13

1,3

3

12

1,4

A

11

2,1

4

10

2,2

5

9

2,3

6

8

2,4

B

7

3,1

7

6

3,2

8

5

3,3

9

4

3,4

C

3

4,1

*

2

4,2

0

1

4,3

#

0

4,4

D

Example:

    'Program to show the keypad status using LEDs
    #chip 16F877A, 20

    'Keypad connection settings
    #define KeypadPort PORTB

    'LEDs
    #define LED1 PORTC
    #define LED2 PORTD
    Dir LED1 Out
    Dir LED2 Out

    'Declare a 16 bit variable for the key value
    Dim KeyStatus As Word

    'Main loop
    Do
        'Get key
        KeyStatus = KeypadRaw          ' <<< the KeypadRaw instruction

        'Display
        LED1 = KeyStatus_H 'High Byte
        LED2 = KeyStatus 'Low Byte
    Loop

Key line: KeyStatus = KeypadRaw — reads all 16 key states at once into a single word, so any combination of simultaneously pressed keys can be recovered by testing individual bits.

See Also:

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