WAITKEY
From MCS Wiki AVR
Contents |
Action
Wait until a character is received.
Syntax
var = WAITKEY()
var = WAITKEY(#channel)
Remarks
var |
Variable that receives the ASCII value of the serial buffer.
Can be a numeric variable or a string variable. |
#channel |
The channel used for the software UART. |
While Inkey() returns a character from the serial buffer too, INKEY() continues when there is no character. Waitkey() waits until there is a character received. This blocks your program.
See also
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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