3x4 keypad -- > Grayhill

Other Hardware General Electronics
1

Hi to all.

Does someone knows what are the rows and columns for this keypad ?
There is 7 pins male connector on the back side but i can not define what is what.
I found one data sheet bum am dont know how to read the truth table correctly.

I have 4 resistors soldered on my PCB but i can not define keypad rows...

Any input is more then welcome !

Grayhill 88AB2-152

2

Which image does it look like?
https://www.google.com/search?site=&tbm=isch&source=hp&biw=980&bih=244&q=3x4+keypad&oq=3x4+key&gs_l=img.1.1.0l5j0i30j0i8i30l2j0i24l2.4225.13994.0.16159.7.7.0.0.0.0.124.784.0j7.7.0....0...1ac.1.64.img..0.7.782.EBCoOMCJ3Zo

3

Like this:

Its 88 series.

4

See table:

http://www.grayhill.com/assets/1/7/Keypads_88.pdf

image.png
image.png800×433 131 KB

.

5

Solved. Thank you.

Well there is still a problem. I run one simple code on one standard 3x4 matrix and it's working as it should ( i connected 8 pins directly to mega board + 4 resistors on rows) . After i have connected Grayhill keypad ( on the same way ) i can get any output. Not even wrong ones :-)
Nothing... Any idea why is this happening ?

6

OK. Any help is welcome because am running on low battery :-)

Am using pins 45, 44, 43, 42, 41, 40, 39 on the arduino mega board.
Pins 45,44,42,38 are connected over 10k resistors ( look at link ).

http://tinypic.com/view.php?pic=xexag&s=9

If i use this code:

const byte ROWS = 4; // four rows
const byte COLS = 3; // three columns
char keys[ROWS][COLS] = {
{'1', '2', '3'},
{'4', '5', '6'},
{'7', '8', '9'},
{'*', '0', '#'}
};

byte colPins[COLS] = {39, 41, 43};
byte rowPins[ROWS] = {40, 42, 44, 45};

i can trigger just keypads 8, 9, 0 and #.
Nevertheless, i get wrong outputs for this ones too.
Keypad 8 = 9
Keypad 9 = 7
Keypad 0 = 6
Keypad # = 4

What could be a problem ?
Any input is welcome !

7

It's likely you have the rows/columns wrongly defined.

Using a simple multimeter (or 3v battery and an LED if you don't have one) double check that what you think are the correct rows/ columns are indeed those.

So connect a row to a column and press the keys on the matrix until you get a response. If you get none then you are not connecting a row with a column. If you do get a response then work onto the next column to get the next set. And so on.

If that all works out just try shorting the Mega ROW pin to the COL pin that you think should work and see whether the MEGA gives you the expected response. (All without using the keypad).

8

Hi,
Looking at LarryD's link.

I see there is quite a few pins some are only for the "single pole common bus terminal" while some are also for the "matrix terminal. It looks like they are all on the one header on the keypad.
If you carefully check which pins you are using.
If it is the one in the spec sheet above then pins D to K are for the matrix (they don't use I for a pin to avoid any confusion).