Remote-processing CAMBASIC Manual de usuario descargar pdf (Pagina 199)

Event Multitasking - 10

Line 80 returns program execution to the place that it was executing before the key was pressed.

Inputting Multi– digit Numbers

The basic examples print out the key that was pressed. The following example is a variation of the basic 16– key demo

that inputs a multi– digit number.

10 'Input a multi–digit number

30 ON KEYPAD$ GOSUB ..Key_interrupt

35 PRINT R

40 DELAY .25

45 GOTO 35

50 ..Key_interrupt

55 B$=KEYPAD$(0)

60 IF B$=CHR$(13) THEN ..Get_value

65 IF B$="*" THEN B$="."

70 A$=A$+B$

75 RETURN

80 ..Get_value

85 R=VAL(A$)

90 A$=""

95 RETURN

Line 30 tells CAMBASIC to call a subroutine by the name of “Keypad_interrupt” every time a key

is pressed.

Line 35 prints the number that the input string will be converted to. Initially, it will be zero.

Line 40 is a 0.25 second delay for demonstration pur poses.

Line 45 is used only as part of this demo program so that the system will wait. You could insert the

rest of your control program.

Line 55 assigns the input to B$.

Line 60 tests to see if this is the term inator key for the input.

Line 65 tests to see if the input is an asterisk. If so, it converts it to a decimal point.

Line 70 adds the new value to the string.

Line 75 returns program execution to the place that it was executing before the key was pressed.

Line 85 converts the assembled string into a number.

Line 90 clear the assembled string to a null string.

Line 95 returns program execution to the place that it was executing before the key was pressed.

Fast Branching on Keys

Sometimes the input data is in the form of symbols. That is, rather than numbers and letters, the keypads legends might be

direction arrows or words like “Load” and “Stop”.

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Remote-processing CAMBASIC Manual de usuario Pagina 199