I realise there’s a few people taking this mod approach at the minute and a few new logs started up, which is a good thing I think!
Anyway, here’s my log. The intention of this log is to show to people that beginner’s can make mod controllers. As a background, I have no experience of modding nor of any electronic work. So, if that sounds like you, follow this log if you wanna make your own mod controller. This one will be a 4 x 4 grid in the Midifighter shape for 8 cue points per decks, hopefully with LEDs.
Here’s the numpad that I’m using.
This is my first post, and I’m needing help already!
I’m wondering how I will be wiring the buttons to the brain and how I can calculate what connects to where. There are 4 pics attached. They are front view and rear view of brain, the keypad with the underneath plastic layout part (which was folded up in half and had a ribbon connector that slot into the connector socket) and then one of the plastic part opened out.
looks like there are 12 contacts just before the ZIF slot - you probably need to solder 12 wires to each of those points. You then need to find earth. Once that’s done you can daisychain 12 buttons to each other (daisychain the earth) and then solder the wires to each of the 12 buttons.
weird that there is 12 contacts - hopefully I can’t see a few other contacts… if there’s only 12 then it’s possible that the numpad uses some sort of matrix/mux… which would be a pain for a beginners project.
edit: oh dear - judging by the plastic contact sheets, it doesn’t appear that all 12 contacts are used on the ZIF socket anyway. Looks like 3 or 4 are unused which might mean that they’re in a matrix circuit… bit beyond my abilities… perhaps someone else can help?
The black bit slide out so the ribbon can slide into the ZIF slot, then pushing the black bit back in lock them in place. Would this work with wires too, or would they definitely need to be soldered?
There is also a green LED on there, assumingly for the num lock. I’m hoping to put the num lock on the side of the case with the LED and USB socket, then have the 4x4 grid on top. Does that look possible with this board?
you sound a bit like me 6 months ago! I spent ages trying to work out a way to make a DIY controller without doing any soldering (or as little as possible). It really isn’t possible to make a controller without doing some soldering, I’ve come to find out!
The good news is that it’s easy… just takes a bit of practice
So no, I seriously doubt you can just stuff some wires into the ZIF socket and hope that they stay in place. You need to solder wires directly to the solder points just before the ZIF socket, I’d imagine.
The ZIF socket is the largest plastic bit on the board. The one where you usually get ribbons (thin plastic usually) that slide into them and lock in rather than loads of wires (or so I understand it).
MiL0 - on the second pic, you can see the ZIF socket has some soldering behind it on each of the 12 strips. Is this where I should be soldering the wires? Is there a way to completely remove the ZIF socket.
what you could do is precisely copy the circuit on the plastic contact sheets. That way, if there is some sort of matrix being used, it’ll still work properly.
the contact sheet circuit is quite easy to see - should be relatively simple to emulate with wires and arcade buttons. The bonus should be that you won’t need to do as much soldering
Nothing complex about that Numberpad. Some have that socket and some don’t. Same goes for keyboards.
The sheets of plastic with white dots on them have conductive traces leading back to that socket. When the top sheet is pressed onto the bottom sheet the white dots touch and complete the circuit which types out a character.
So with this in mind you first need to decide which characters you want to use then follow the traces back to the socket on both the top and bottom sheet (Please note that a multimeter with built in Continuity tester will make light work of this process)
As an example say you want to use the number 1 button.
You follow the trace from the white dot on the top sheet and it goes to pin 3 on the socket, then you do the same for the bottom sheet which might lead to pin 7 (these are just examples)
So what does this tell us?
Well now we know that pin 3 and 7 create the number 1 so if you was to solder a wire to each of these pins and then touch them together it would type out the number 1. You will find that some numbers lead back to the same pin like in this image.
This is example from this project.
Repeat this process for the other buttons.
As for pushing the wires directly into the socket. That is the first thing I would try, you might get lucky.
Sorry, complete noob here. But what exactly does this mean?
I’m assuming what you mean is treat the circles on the plastic sheets as the arcade buttons and the straight lines as wires, and kind of daisy chain the arcade buttons as per the mapping on the plastic contact sheet. Am I right in thinking that?
If so, how would I daisy chain the arcade buttons?
daisychaining the arcade buttons might mean soldering more than one wire to each terminal on the arcade button… you need to look at the plastic contact sheets and work out what’s going on.
if no one else attempts it, I’ll try and knock up a wiring diagram in mspaint later tonight.
also, extraclassic is right on the money… you don’t need to understand how the matrix works… just that by completing the circuit in different ways causes one of the numpad buttons to be pressed. Have you got a multimeter? If not, time to get one! They’re very cheap on eBay (mine was less than £5) and are pretty much essential for this kind of project.
yeah that’s the one I got (mine was a few quid cheaper but from China).. it works pretty well except that it doesn’t have a buzzer… just a visual alert instead.
I think Maplin are doing a cheap one at the moment too:
Fab stuff! Got two Maplin stores within a mile and they’re opening a third within about three minutes of my flat in a couple of weeks. Will pop in tomorrow to pick up the multimeter you linked to. Cheers Mil0!
Ok, from the pointers so far. I’ve tried to work the mapping out on the plastic cointact card. The numbers are the number on the 12 ‘ZIF’ contacts. As far as I understand from looking at the ribbon connector, the first 3 aren’t used. Now, I think I’ve worked it all out, but need someone who understands it to check if possible please.
Find this thread fascinating. Good effort on starting this mate.
Now that you know which wires have to connect to generate each number on the numpad whats next? how does this info now help you to the next stage of your mod?
