Upper Key Limit?

[degroof]

Not submitting as a bug (I've already written a workaround). Just curious...

I ran into an issue where the keypad library was working fine for a 6×10 matrix (i.e. 6 rows, 10 columns) but started giving phantom key codes for a 5×15 matrix. The symptoms were as follows:

• I would press a key and get a keypress event for that key.
• This would be immediately followed by 2 keypress events for a completely different key.

From what I can tell, this appeared to be due to something akin to a buffer overflow issue.

Is it possible there's an upper limit on the number of keys the library can scan? It seemed like the limit was somewhere between 60 and 75. I'm guessing 64.

Hardware: Adafruit Feather M0 Bluefruit LE (ATSAMD21G18).