how do TOY switches work? (matrix switches??)

[loss1234]

Hello. I am new to bending and have been having some luck but one area I can find NO information on is how the buttons/switches work on 90 percent of newer toys. From what I can tell there is a gold circuit board area where a rubber button touches (makes contact) to turn the sound or light or song ON but what i want to know, is how can i rewire or remove the switches and use them in something else.

I get how a pot works but these switches all seem to connect to a common bus and then travel down some thin cable. Do they HAVE TO HAVE A GROUND or can i just connect the wire to another device?

ALSO, what kind of signal do these send out? is it resistance based like a pot or is it a logic signal?

any info or schematics appreciated.
I have tons of toys with these sorts of matrix switches and i cant figure them out for the life of me.

[Kassen]

Yes, nearly always it's a matrix, meaning a button will make a connection between one of a number of pins "A" and one of a number of pins "B". The one set is the matrix's inputs, the other the outputs.

This comes down to a logic signal. What happens when you connect these to other devices is anybody's guess; it might mean the first device will do something, perhaps the second will, perhaps both, perhaps neither. Perhaps this will be influenced by the button. Perhaps smoke will come out.

The way these matrices are build (cheaply without diodes to prevent this) means that pressing certain combinations of two buttons might result in a third button's signal being send as well. The good news is that buttons are relatively expensive as parts of toys so sometimes some buttons get removed from the design during development so for some devices it's possible to access extra sounds by holding down odd combinations of buttons.

Pots are cool for lots of things but typically not in these matrices, at some setting the pot will make the voltage drop below the input's treshold resulting in a dead connection so you might as well use switches if that's functionality you are interested in.

Happy bending.

[loss1234]

"The one set is the matrix's inputs, the other the outputs. "

so how do i go about figuring out which wire is for the input and which for the output? is there a way to test them or use a voltmeter to figure it out?

or are there any books or links that might explain it more in depth (or with a diagram?)

sorry to be a pest but i'd love to learn how to use/fix these.
often the flimsy ribbon cables connected to these buttons break when i open the case up, and if i knew which button needs which wires, maybe i could repair and or reconfigure the buttons.


i appreciate the help

[theMinister]

http://www.sailormouth.org/index2.php?pg=membrane.inc
thats specific to a speak& keypad but all matrices are essentially the same. think of it like battleship, a grid of numbers and letters and where the lines cross you have a connection being made. most are easily replaced with momentary on switches, or some combination of switches. sailormouth has moe on that. if holding the button down causes the toy to repeat itself a patchbay might work as well.

[Luka]

i broke the matrix ribbon on my speaknspell when i was cutting a hole for my trigger patchbay.

if you can work out a way to rebuild it loss, pls report.

instead i am about to work out a way to trigger the buttons using a differnt kind of matrix. i think i may use sinesurfers's ems matrix patchbay to do it now as its compact.
link>
http://www.strings.ph.qmul.ac.uk/~thomas/synthdiy/patchpanels.htm

in the end this will work out really well as now i haveroom for my sequencer triggers and a big body contact section