Arduino Nano 5x5 button Matrix unreliable

[frumpy]

Hi guys,

I built a 5x5 matrix with a Nano. I'm using relatively high-quality buttons. No further electronics like diodes or capacitators.
In general, AM detects the keypresses. Sometimes I have to press a button 4-5 times until the buttons gets recognised. Sometimes
they work just from the start. I cannot detect any row of column that is unreliable.

I will continue testing the current and resistance, but I wonder if there is any general fault in design? I've read about other people
doing a button-matrix.

Also a high-quality encoder is connected, it transmitts signals with a reliability of 80%. Direct pins, no matrix. I suppose I need to connect capacitators?

[Keith Baxter]

Hi,

The matrix requires diodes to work properly.

Something like this.

Keith

[Ralph]

Aren't the diodes just for when you want to press multiple button at the same time?

[frumpy]

Diodes are for double button presses, yes. Since I don't need this feature, I'll save 25 diodes.
It turned out one button was unreliable, also two soldering connections did not work correct either. I resoldered stuff and now things look better.