keypad matrix - daisy chain

Projects General Guidance
1

i'l like to have a 10x8 key pad matrix.. but the ones i found are usb based and cost like $226-$245

IE:

sooo.. only thing i can think of now is to daisy chain (4) 5x4 keypad matrixes with (4) 74hc595's and which would be perfect..

however, all i find are these 4x4's.. which would take 5 but would not align the way i want them to..

IE:

it seems there is never anything exactly what i want to find.. well, i found these.. but they don't show a price.. and the last 2 columns are not evenly spaced as the first 3 are.

IE:
![](https://2.imimg.com/data2/SP/VI/MY-1153657/5x4-keys-matrix-keyboard-interface-module-
500x500.jpg)

and to put these keypads in an enclosure, the buttons don't stick up high enough..

2

anybody have any alternatives or how i could do this 80 button matrix?

3

(deleted)

4

you can use a Adafruit Trellis and link up to 8 of them together to make arrays of different shapes and the modules maintain the same key pitch as the array is expanded

5

spycatcher2k:
Design the PCB and have it made. :slight_smile:

yeah i could.. if i really knew how.. been looking at easyEDA and such.. believe me i'd really like to start designing my own i'm just not good at that stuff.

clarktrans:
you can use a Adafruit Trellis and link up to 8 of them together to make arrays of different shapes and the modules maintain the same key pitch as the array is expanded

Adafruit Trellis Monochrome Driver PCB for 4x4 Keypad & 3mm LEDs : ID 1616 : $9.95 : Adafruit Industries, Unique & fun DIY electronics and kits

again, that also takes 5 of them to connect and not align the way i want them.. it's the same issue as the second picture in my first post.

6

Solder breadboard

7

just really wanted to see if anybody knows of a 5x4 instead of the 4x4 in my second picture in my first post.. i guess ultimately i'll just stick to designing my own and have it printed out.. tho i find it too costly for a more than likely 1 time project.

8

(deleted)

9

The picture of the "keyboard interface" board is designed to have keycaps on top of the switches.

Paul