i am working on a project which uses a keypad, LCD with PIC16F877A, so can i please know how a buzzer can be used to alert a sound when a wrong password is entered through the keypad?
hi shiny,
as the early reply suggested you have to alter the software and you might want to use a transistor switch without driving it straight from the O/P pin so the pic won't be supplying the current directly to the buzzer. the supply voltage (9V shown here) will change according to your buzzer specifications but it will work ok with 5V. as for the transistor you can use any general purpose NPN transistor.