INKEY

Action

Returns the ASCII value of the first character in the serial input buffer.

 

 

Syntax

var = INKEY()

var = INKEY(#channel)

 

 

Remarks

Var	Byte, Integer, Word, Long or String variable.
Channel	A constant number that identifies the opened channel if software UART mode

 

If there is no character waiting, a zero will be returned.

Use the IsCharWaiting() function to check if there is a byte waiting.

 

The INKEY routine can be used when you have a RS-232 interface on your uP.

The RS-232 interface can be connected to a comport of your computer.

 

As zero(0) will be returned when no character is waiting, the usage is limited when the value of 0 is used in the serial transmission. You can not make a difference between a byte with the value 0 and the case where no data is available.

In that case you can use IsCharwaiting to deterimine if there is a byte waiting.

 

 

See also

WAITKEY , ISCHARWAITING

 

 

Example

'-----------------------------------------------------------------------------------------
'name : inkey.bas
'copyright : (c) 1995-2005, MCS Electronics
'purpose : demo: INKEY , WAITKEY
'micro : Mega48
'suited for demo : yes
'commercial addon needed : no
'-----------------------------------------------------------------------------------------
 
$regfile = "m48def.dat" ' specify the used micro
$crystal = 4000000 ' used crystal frequency
$baud = 19200 ' use baud rate
$hwstack = 32 ' default use 32 for the hardware stack
$swstack = 10 ' default use 10 for the SW stack
$framesize = 40 ' default use 40 for the frame space
 
Dim A As Byte , S As String * 2
Do
 A = Inkey() 'get ascii value from serial port
's = Inkey()
If A > 0 Then 'we got something
 Print "ASCII code " ; A ; " from serial"
End If
Loop Until A = 27 'until ESC is pressed
 
A = Waitkey() 'wait for a key
's = waitkey()
Print Chr(a)
 
'wait until ESC is pressed
Do
Loop Until Inkey() = 27
 
'When you need to receive binary data and the bibary value 0 ,
'you can use the IScharwaiting() function.
'This will return 1 when there is a char waiting and 0 if there is no char waiting.
'You can get the char with inkey or waitkey then.
End

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