AVR Push button problem

[nzkunal]

push button avr

I am having some problem using a push button with an AT90S8535.

Basically the PB is connected to supply negative (GND) and the other end to an input pin PORTB.2. PORT B direction is input and initial value 1 (High)

When I prees the PB my code doesn;t seem to respond. I have checked the hardware connection i.e PORTB.2 does actually go to GND when PB is pressed, cant figure out why code doesn't respond. Is checking if PORTB.2 = 0 or 1 the right way to do it can anybody suggest some simple test code.

 

[SphinX]

avr push button

Hi nzkunal,

I have no exprience with AVRs.
But Does PORTB have internal pullup resistor? If yes?

If No, you must connect a resistor (~ 4.7k) from the PORTB.2 pin to VCC

So the PB in open state the PORTB.2 is High , when you press the PB the PORTB.2 be LOW

So just read the input of the PORTB.2 to know if it's close or open.


Bye

 

[nzkunal]

avr push

Sorry, problem solved... before anyone points it out I just realised to read input ports in AVR u have to use PIN not PORT.