12V Mini PCB Relays Arrive

FINALLY! The mini Songo 12V PCB Relays arrived!! There was a slight shipment issue according to the eBay seller so I waited a much longer time for delivery but luckily the first batch of 10 have arrived so now I can begin work on my Relay board for my Lower Console makeshift Space Matt buttons I had made out of the old calculator. You may remember from an earlier post. I basically want the Space Matt buttons to activate the DTMF tones generated by the Knight Rider World Voice Box. Now given the configuration of how my Space Matt buttons are wired and that I am NOT an electronics expert by ANY means this was the best and easiest solution I could come up with. Now these Songo Relays are very tiny and will more than do the job needed by my Space Matt buttons to activate one Relay for the DTMF tone for each button and also another Relay for any given function I choose.

Now like I say I had worked out a diagram that should do the job needed for my Space Matt buttons. As you can see here the DTMF tone request pulse is isolated from the button device function activation pulse. Someone more electronics savvy may have another option but this was what I came up with given my limited electronics knowledge and the way my Space Matt buttons were configured. The Songo relays are very small so I can get a lot of them into a small space by soldering them onto some Proto Board and wiring them in accordance to my diagram.

Lower Console Make Shift Space Matt Buttons Additional Wiring Scheme

"Not now Michael, I have a headache"

There may be a better way of doing this but this is for now how I figure I am most likely to approach this particular problem. You see my makeshift Space Matt buttons I made using an old Texas Instruments Calculator are wired like this; All of the buttons grounds are connected but each button makes and individual connection to that ground. Now the Voice Box's built in DTMF random tone generator request a tone by making a connection to ground. You may be begging to see the challenge here ;) So what I have done in this diagram is I have mapped out a way of using two sets of SPST Relays connected to each of the Space Matt buttons individual ground connection wires. What happens here is the first relay in the "Yellow" zone is isolated that it makes the ground connection for the V.B. DTMF tone request connection. The second SPST Relay in the "Blue" zone is isolated in that each one can momentarily activate a device. I could complicate this further by introducing "Step Relays" in order to make the momentary button into a latching button but lets not go there ;) Complicated I know but it will get the job done and do what I need it to do.

Alternate Space Matt Buttons Wiring Scheme

I was having some issues trying to work out a way to utilize each of my Space Matt buttons that I had made out of an old Texas Instruments Calculator. The problem was that the V.B. (Voice Box) random DTMF tone generator needs a ground pulse to activate a random tone, but with this type of button configuration where all of the buttons are connected to one wire (in this case ground) and the other buttons individual connections to that ground it was difficult coming up with a way to activate both a device and generate a tone through the V.B. So I came up with this idea. Seen here in my diagram I have two buttons wired to show a way in which they can all be wired in the same way to do just that, activate a device and generate a tone. In my diagram the ground connection through any one chosen Space Matt buttons will activate the relay's magnetic coil causing it's internal switch to close, in this case the needed ground connection from the V.B.'s DTMF tone generator to ground. It's a bit daunting having to use all of those relays but I can't think of another way off hand how to do this. Maybe those small "Songle" I think is the name of them relays would do the trick for this?

Example Image of "Songle" relay.

Testing Out My Calculator Space Matt Buttons

Although I have not gotten all of the wires from my make shift Space Matt Buttons wired into Molex Connectors yet, almost there just need to get some more 22 AWG wire as I ran out yesterday. I figured I would work out a diagram of how the buttons are configured and what I'm proposing to do with them in regards to using them to cycle through the message in the Message Centre and have then produce a random DTMF tone from the built in tone generator in the Knight Rider World Voice Box (V.B.)

Theoretically I'm thinking this should work based on the instructions that came with the Knight Rider dash electronics. As you can see in my diagram I have combined all of the momentary switch button wires into one wire to ground, they do have the option to be used individually in the future as I have wired them up to the Molex connectors separately. But for my immediate purpose right now just a single ground signal from all of the buttons to cycle through the Message Centre and request a random DTMF Tone from the V.B. will do for now. I know from my test yesterday that the Message Centre will cycle through with a simple Momentary switch. My only concern right now is are the V.B. DTMF Tone Generator and the Message Centre momentary switch options wired the same way?? This is something that needs to be figured out.

NOTE: Today I did a Multi Meter test on both the Message Centre Cycle Connections and the V.B. DTMF Tone Request Connections and get a reading of around 3.9 when set to DC Voltage so I think they are set up the same way as far as input signal. 

Installing And Wiring My Space Matt Buttons

"Buttons, Wires and Connectors, Oh My!"

Well I installed my make shift Space Matt buttons a little differently that I wanted too. I was going to cut out my rectangular hole a little bigger so as to sink the Space Matt buttons array into the hole so it would sit flush, but I'm a little hesitant to do that because the hole is cut to the size of the USB Space Matt Keyboard buttons that you can get from Knight Rider World, and like I say these may just be temporary buttons for me to use until I get around to ordering the USB buttons. Of course me doing it this way means that my plastic overlay I made is a little too thick for how I have the Space Matt buttons placed into the console as in they sit a little deeper down. I may make a thinner overlay out of some metal stock I have kicking around, I'll see what ends up looking good.

I had drilled in a large enough hole into the top of the fibreglass console to be able to thread in my wires for all of the buttons. I had to add a little more length to the wires so I would have a little more room to put in my Molex Connectors. I had to get a couple of 15 Pin Connectors as the electronics place did not have anything bigger. That's OK though, it just means having another connector sticking out of the wire loom ;) Each one will be clearly marked so they can't get confused so no biggie.

I have the one wire that connects all of the buttons together on the far side of the Molex Connector and then the 4 rows of individual wires for each button connection using up the remaining pins of the connector. This way I can organize them on the connectors in rows from top to bottom. Here in this picture on the left you can see I have started putting together the wires into the connector, I have the main buttons feed wire in place and the first top row of buttons wires in place, now to complete the connectors by following the same format. ;)