I'm busy fiddeling around with a microcontroller, keypad and lcd and have question about the lcd backlight.
everytime I press a key on the keypad I would like the lcd backlight to come on for say 2 seconds. if another key is pressed the light stays on. if no key is pressed within 2 secs the light goes off.
the problem is that i've run out of pins on the microcontroller so am looking for another way to do it - otherwise I could have used some coding to do it. When a keypad is pressed a buzzer makes a short beep.
Now my question - can I link the buzzer to some kind of timer (555?) to do the switching of the light on and off.
Can anyone offer any help - am I on the right track, or is there an easier way?
everytime I press a key on the keypad I would like the lcd backlight to come on for say 2 seconds. if another key is pressed the light stays on. if no key is pressed within 2 secs the light goes off.
the problem is that i've run out of pins on the microcontroller so am looking for another way to do it - otherwise I could have used some coding to do it. When a keypad is pressed a buzzer makes a short beep.
Now my question - can I link the buzzer to some kind of timer (555?) to do the switching of the light on and off.
Can anyone offer any help - am I on the right track, or is there an easier way?