How to scan keys on this triangular keyboard

holikey

How to scan keys on this triangular keyboard [Copy link]

The bottom row is connected to GND, and the others are connected to IO. When scanning the keys, set the first row to 0, scan the first column, set the second row to 0, scan the second column, and so on. But when you scan and press the bottom row of keys, it will always pull down the other rows being scanned, causing the result to be wrong. Can anyone tell me in detail how to scan to solve this problem? I'm new and need it urgently. .

ddllxxrr

I think it needs a joint scan, that is, select the upper half as 1 and read the lower half, and then vice versa, the lower half is 1 and read the upper half, and then a key value can be determined.

maychang

"The bottom row is connected to GND, and the others are connected to IO. When scanning keys, the first row is set to 0, the first column is scanned, the second row is set to 0, the second column is scanned, and so on. However, when the bottom row key is pressed, the other rows being scanned will always be pulled down, causing the result to be wrong." Why should the bottom row be grounded? If the bottom row is also connected to an I/O port line, can't it be scanned? This triangle connection method is not as good as a rectangle (matrix connection method).