Button Array - Do I need to use diodes?

[JockMunro]

Hi,

I'm looking at building a button array using hw_button_array_add to interface a 737 CDU. I've been researching stuff and note most matrixes (matrices?) use diodes to stop ghosting. Is this something we should use with AM? I note diodes are not used in the example given on the AM Wiki but here https://www.baldengineer.com/wp-content ... xample.jpg, for example, they are.

Thanks a lot.

Jock Munro

[Ralph]

Shouldn't be necessary, but I can't vouch for each setup, you'll have to try to be sure.

[JockMunro]

Thanks Ralph.

That'll make it simpler. I'll run some tests first though.

Cheers

Jock

[Keith Baxter]

Hi,

Just a heads up. There is a limit to a matrix. If memory serves it is 8 on each row or column (8x8). Remember asking when I was going to use a RPi for a CDU.

Keith

[Sling]

Diodes are required if there is a risk of multiple button presses at once. If you can understand what the ghosting term means and its implications you'll understand why you may choose to use the diodes or not.

Tony

[jph]

Diodes are required if there is a risk of multiple button presses at once. If you can understand what the ghosting term means and its implications you'll understand why you may choose to use the diodes or not.

Tony

Agreed,