Remote-processing BASIC 52 Uživatelský manuál stáhnout pdf (Strana 69)

RPBASIC-52 PROGRAMMING GUIDE

2-50

KEYPAD

Syntax: A = KEYPAD(function)

Where: function = 0 or 1

0 = return keypad position pressed from buffer

1 = returns number of keys in buffer

Function: Returns keypad pressed position or number of keys in keypad buffer.

Mode: Command, Run

Use: A = KEYPAD(0) Returns a keypad position

Cards: All

DESCRIPTION

The keypad is automatically scanned, debounced, and placed in an 8 position buffer in the background. Key

presses are buffered until retrieved by the KEYPAD(0) function. Keypad positions are returned as a number

from 1 to 24. W hen a 0 is returned, there are no more keys in the bu ffer.

Position numbers 1 - 4 correspond to the top row while positions 12 - 16 are the bottom row of keys on the

KP-1 and KP-3 keypads. Thus, the letter 'B' on the KP-1 corresponds to position 8.

Use CL EAR KEYPAD to remove all characters from the buffer.

ON KEYPAD branches to a subroutine when a key is pressed. (check card for availability)

CLEAR KEYPAD, ON KEYPAD

ERROR

BAD DATA When function is out of range.

EXAMPLE

The following program prints out the keypad position as a key is pressed.

10 CLEAR KEYPAD

20 DO

30 UNTIL KEYPAD(1) = 1

40 PRINT KEYPAD(0)

50 GOTO 20

1 2 ... 64 65 66 67 68 69 70 71 72 73 74 ... 162 163

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Remote-processing BASIC 52 Uživatelský manuál Strana 69