Mikroelektronika MIKROE-350 Ficha De Dados

477

- SOFTWARE AND HARDWARE SOLUTIONS FOR EMBEDDED WORLD

CHAPTER 6

PORTC is inverted on every PORTB.B0 one-to-zero transition :

program Button

' Button connections
dim Button_Pin as sbit at PINB.B0       
dim Button_Pin_Direction as sbit at DDRB.B0 
' End Button connections

dim oldstate as bit    

' Old state flag

main: 

Button_Pin_Direction = 0          ' Set Button pin as input

DDRC  = 0xFF                      ' Configure PORTC as output
PORTC = 0xAA                      ' Initial PORTC value

oldstate = 0                      ' oldstate initial value

while TRUE 

if (Button(1, 1) = 1)           ' Detect logical one

oldstate = 1                  ' Update flag

end if
if (oldstate and Button(1, 0)) then ' Detect one-to-zero

transition

PORTC = not PORTC                ' Invert PORTC
oldstate = 0                     ' Update flag

' Endless loop

end.