Go Down

Topic: Testing whether a pin is an interrupt (Read 6066 times) previous topic - next topic

baum

So I only need 4 diodes? (I only have 5 in stock...)

And if this works, I can put everything on port b, simplifying things greatly.

baum

CrossRoads

"So I only need 4 diodes?"
That depends on what you are doing. As I said, my design used a combination of things.

If you wiring up your buttons like a 4x3 keypad, then yes.
If you are going with 12 buttons into 12 pins, then you need 12 diodes.

Here is the idea behind the 4x3 matrix.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

baum

Alright. But couldn't I make a 3x4 matrix and use only 3 diodes?

CrossRoads

Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

floresta

Maybe he's lying down and looking at the drawing sideways.

Don

baum

Terribly sorry... I was referencing CrossRoads's original drawing.
baum

Go Up