Working on a fully custom keyboard [SCHEMATIC]

MasterControl90

18 Aug 2020, 10:09

Hi,

I'm another madman going all in for a totally custom keyboard, I just need some sanity check.... Is this matrix schematic correct? thanks!
Schematic_60% custom_2020-08-18_10-01-30.png
Schematic_60% custom_2020-08-18_10-01-30.png (509.33 KiB) Viewed 465 times

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vvp

18 Aug 2020, 20:18

Looks OK. You may want to assign columns (green lines) to ports PB and PD only. You will save two instructions when reading out the column data. You will need to read PB and PD only instead of PB, PC, PD and PF (as you have it now).

MasterControl90

19 Aug 2020, 09:37

vvp wrote:
18 Aug 2020, 20:18
Looks OK. You may want to assign columns (green lines) to ports PB and PD only. You will save two instructions when reading out the column data. You will need to read PB and PD only instead of PB, PC, PD and PF (as you have it now).
OOF, thanks buddy, for whatever reason I wasn't sure the matrix itself was correct. Thanks a lot! :D

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vvp

19 Aug 2020, 11:48

The matrix itself is fine.
You select one row by setting the corresponding red line to 0V output. The other red lines are disconnected (temporarily set to input) or set to 5V output. Then you read all the column lines at once. The columns which return logical low are the ones in which a switch is pressed (and it is pressed in the selected row).
You do not have external pull-ups on the column lines but it does not matter. You must enable the internal pull-ups in ATmega32u4.
Good luck with your project.

Edit: You do not have any LEDs there. Most people want at least CAPs LED. I have all four of them.

kelvinhall05

20 Aug 2020, 19:34

This matrix looks good. If I were you, I'd switch to a Pro Micro and make the matrix not look exactly like what the keyboard's layout will be (for example, if you have a 5x14 matrix for a 60%, you can use an 8x8 matrix and that will fit on a Pro Micro without having to use the two onboard LED resistors as pins for your matrix).

gipetto

21 Aug 2020, 11:42

kelvinhall05 wrote:
20 Aug 2020, 19:34
This matrix looks good. If I were you, I'd switch to a Pro Micro and make the matrix not look exactly like what the keyboard's layout will be (for example, if you have a 5x14 matrix for a 60%, you can use an 8x8 matrix and that will fit on a Pro Micro without having to use the two onboard LED resistors as pins for your matrix).
duplexed matrixes are really confusing though

kelvinhall05

21 Aug 2020, 15:57

gipetto wrote:
21 Aug 2020, 11:42
kelvinhall05 wrote:
20 Aug 2020, 19:34
This matrix looks good. If I were you, I'd switch to a Pro Micro and make the matrix not look exactly like what the keyboard's layout will be (for example, if you have a 5x14 matrix for a 60%, you can use an 8x8 matrix and that will fit on a Pro Micro without having to use the two onboard LED resistors as pins for your matrix).
duplexed matrixes are really confusing though
Good thing I didn't suggest a duplexed matrix :)

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