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Commands - 67

KEYPAD$

Process Function

SYNTAX: a$= KEYPAD$(0)

a= KEYPAD$(1)

PURPOSE: To return a one– character string in response to a keypad input or return the position of the key.

REMARK S: KEYPAD$(0) returns a single– character string that has been assigned to a key. It is most useful on

16– key devices. If no key was pr essed , or if you r ead the keypad again before another key is

pressed, a null string is returned.

KEYPAD$(1) r eturns the key position. Keypads often have legends that ar e not single letters. T hus,

the first syntax may not make sense. If no key was pressed, or if you read the keypad again before

another key is pressed, a zero is returned.

A table in RAM can be programmed to return any A SCII value. The table is set up so that the first

character is in the upper– left– hand corner and the last character is in the lower– right– hand

corner. See SYS(8).

You can assign a single– character string to the keys in the following manner.

10 FOR X=0 TO 15

20 READ A$

30 POKE SYS(8)+X,ASC(A$)

40 NEXT

50 DATA 1,2,3,A,4,5,6,B,7,8,9,C,*,0,#,D

This example matches many 16 position keypads.

RELATED: ON KEYPAD$, INPUT KEYPAD$

EXAMPLES: 40 ON KEYPAD$ GOSUB..Key_interrupt

50 GOTO 50

60 ..Key_interrupt

70 PRINT KEYPAD$(0)

80 RETURN

The RPC-2350 requres an extra parameter (16 or 24) after KEYPAD$ to designate keypad size.

ERROR: none

1 2 ... 95 96 97 98 99 100 101 102 103 104 105 ... 207 208

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Remote-processing CAMBASIC Manuale Utente Pagina 100