Insert Coffee - Circuit problems

[EightBySix]

Good spot - it is a JLF. The height was a trade off. I have limited vertical space for it - To mount it any higher I would have had to make the table base deeper to avoid rubbing my knuckles on the wood above. As it happens I tend to play with my finger tips anyway, so it's all good.

I think I'm happy with the microswitch sound levels now - I quite like the noise, but it's more 'classy' now 

[EightBySix]

Whilst I'm sanding parts and wating for various layers of oil to cure, my mind has turned to the admin buttons.

I'm aiming to embed capacative touch buttons below the veneer and acrylic top - in the bezel. This obviously wont work for buttons used during play, for the same reason iMame sucks without a proper controller.

For infrequently used buttons though, it should be a nice convenient way of accessing functions without cluttering up the control panel.

The idea is to have a grid of metal areas to represent the buttons, with some sort of visual but non functional panel on top.

The metal functions as a capacitor, that is charged/discharged frequently and the average charge time is measured. When your finger is nearby - it changes the capacitance and therefore the charge time, which is detected and counts as a button press.

Thats the concept. In practice, I'll be ordering a microcontroller this weekend (probably in the PIC 18 family) that has a CTMU (charge time measurement unit) built in.

The metal plates will be either an etched pcb, and the button images above could be marquetry icons in the veneer, or possibly I could etch some brass (laser cut would be nice - but cant find anwhere that would be cheap enough) in the shape of the icons and put them on top of the veneer, but under the acrylic top.

With a bit of coding on the microcontroller, I should be able to get a button press to send a signal to the iPac to represent a keypress.

I'd like to incorporate some feedback if possible. I've already ordered a small electro luminescent sheet to see if it will show through the veneer in the same way I did the LED matrix, so the button could light up on a press. Not sure if it would introduce electrical noise and screw up the capacitance etc though. I'll have a play and see. Alternatively, I could embed one of the tiny vibrator motors like those in phones.

Trying to post my thoughts in detail (and any progress I make) - in case any of you guys with CP art could make use of the idea - some kind of subtle indication on the image to indicate the button location might be fun to try and incorporate. If it's on the CP you would have to have some kind of shifted setup though I guess.

[CoryBee]

I like this idea and will keep a close eye on this part of your build. I have messed with building simple touch circuits before. If you go that route many props to you, but here are two things you might want to take a look at.

The "Makey Makey" - http://www.makeymakey.com/

They are about $30 - $40 bucks though

Or a super cheap one made from a simple 555 timer - Touch Sensitive OnOff Using 555 timer

By the way I absolutely love this design
 

[Kaytrim]

I am just getting back into the scene and spotted your build.  I have to say I love your taste in tools and woodworking.  Those half blind dovetails were very well done for a first timer.  The LED Matrix is a stroke of genius and I like the other touches you have developed along the way.  Keep it up, you are in the home stretch. 

Kaytrim

[EightBySix]

So much for my Christmas deadline! 

I've fitted in a bit of shed time here and there, so thought it was about time I recorded some progress

Power connector


I got this connector and shaved off the flanges on the edge to make it look a bit more discreet.


I went too far though and it became too small for the gap!
I had to revert back to plan a to cover my mistake. 

Coin-o-matic 3000

I re-did the softwood prototype of the coin counter I made, this time more compact and made of oak. Works a treat although the entry slot isnt big enough for a 50p coin (the biggest) but that's just a bit of filing.

I made a brass slot cover with a dremmel and some needle files. Turned out OK, but tarnished quickly. I painted it with some clear nail varnish but that went off before I could finish painting it. I tried thinning it with some nail varnish remover, but I think that must have some skin friendly additives in it that made the mix lumpy. I wonder if acetone is the thing to use? Anyone?

Boot PC on drawer opening.
This was an epic cockup. I sucessfully wired up an external connection to the power button. So far so good

I made a little brass contact that pressed a microswitch as the drawer slides past, which worked to a point, but it was possible to open the drawer too quickly.

The switch has to be closed for around half a second for it to boot.
So I thought why not have a bit of delay code in the microcontroller that I use for the Coin-O-Matic, with a relay to close the PC switch wire briefly.

All went well, until I realised that the circuit uses the same power/ground as the keyboard encoder, which - wait for it - is only powered on when the PC boots! Doh!

I then decided to use a seperately powered circuit, using a 555 timer and the relay. It was when I was getting my head round the fact that I needed the indefinate 'pulse' of the drawer contact opening to produce a brief output pulse to fire the switch that a thought occured to me.
I went to the PC, pressed the power button and held it. It booted without powering back down after a few seconds as I had assumed it would.

So after all that - I now have a microswitch as a drawer stop, with the PC power switch wired to the normally closed contact. Works a treat and much more simple.

Still - at least I've learned lots of new stuff


With the new microcontroller I bought, I now have more space to hold font bitmaps, so I'm going to double duty the coin-o-matic with the display of the LED data, so thats what I'm working on now. Initially as feedback for the coins inserted, and later as a 'front end' to choose games etc.

[DaOld Man]

Nice work.
All this talk about switches has me interested.

[EightBySix]

Some more progress to report - I *will* finish this thing!

I got around to making the player 2 control panel, and I also took the opportunity to re-do the original. After having had some play time, I realised I didn't want 3 buttons, and the curved layout from slagcoin didnt seem to be needed for 2, so I did them both for 2 buttons and added player 1 & 2 start too, now I had the room.

Here is a picture of them both installed, from above, to show how they both slide in under the monitor.



The black dust washers came with the joystics, and don't look right. I had a go at making some out of wood by partially drilling a hole:



And then taking slices from it:


Trouble is, it looks like crap:


So I'll shop for some white ones to match the buttons. I did consider brass to match the drawer handles, but I think it would look odd.

Now I had my final button setup finished it was time to figure out the capacitive admin buttons - and I DID IT! - I'll post some stuff up about it tomorrow, with a couple of vids.

(by the way - my 3 year old asked me why I had put 'toilet buttons' on. Took me a while to work out she was referring to the sign you get on the door of the gents toilet! Now that's all I see when I look at them  )

[emphatic]

You should get transparent washers, they blend in well and you won't need to colour match.   

[Yvan256]

You should get transparent washers, they blend in well and you won't need to colour match.   

I second the idea. Transparent washers won't detract from the "wooden furniture" look, it would probably also look better than white washers.

[drventure]

I saw "brass" and my ears perked up.  I'd say transparent would look good, but I'm a sucker for brass.

There are some VERY nice brass examples of "knob backplates" on various hardware sites that might work very well too.

black plastic mounted "underneath" would also look very clean

[Yvan256]

Black plastic mounted "underneath" would also look very clean.

Ok I take back what I said and I'm changing my vote to "black washers mounted underneath".

[Nephasth]

Black plastic mounted "underneath" would also look very clean.

Ok I take back what I said and I'm changing my vote to "black washers mounted underneath".

+1... and a little light!

[EightBySix]

Black plastic mounted "underneath" would also look very clean.

Ok I take back what I said and I'm changing my vote to "black washers mounted underneath".

+1... and a little light!

Trouble with that is the thickness of the wood the joystick is mounted on, it would just be a hole in the wood with a dust washer at the bottom. I cant recess the joystick because of knuckle space above.  I'll try white and brass and see how I feel about it.

Little light? I might have a strip of electro luminescent film in the drawer hole to light up the control panel area, but I think that's as far as the bling will go. I did put an led underneath the drawer handles, to give a clue you were supposed to open the drawer when its switched on, but you couldn't really see it. I think it was because there was nothing to shine onto.

Anyway - onto the update. I got a test circuit working with touch areas below the acrylic and took a video. I needed to do this to make sure the electrical noise from the monitor/speakers/etc didn't interfere with it.

Here is a video of it working:

I realised later that iPaq signals need to go low to register a key press  and I'll have to prevent multitouch, which will cause all sorts of issues.

Next I had to decide how to indicate where the touch areas were under the bezel. Two trains of thought here:

• Darker coloured wood icons
• Cut through the veneer to reveal the brass touch pad below

I saw "brass" and my ears perked up.

(this one's for you Doc!  )

Here is a picture of both options:


I think I'm going to go with the brass, but as that's a one way decision I did a mockup of the buttons in darker wood, to play around with the layout. Here is what I'm thinking (sorry about the reflections):


The icons are (from the bottom) Pause/Unpause, Volume on/off, The slider moves the volume up and down, or you'll be able to use the joystick, and exit to menu where you can zip through the list of games with the slider, or use the joystick.

Does that sound logical? Any alternative icon/layout ideas? They have to  be simple enough to cut out easily.

So to implement the touch pads, I made this:


The 'leg' goes through a hole drilled in the bezel to connect to the touch circuit below the monitor.

Here is a vid of it working - just the pause button so far.



The sensitivity needs to be turned down a bit, which is a parameter tweak in the firmware. It's actually quite cool as at the moment you dont actually have to touch it. You can pause the game by just passing your hand over it. Not so useful when the other buttons (exit!) are implemented though 

[Le Chuck]

That's sic man, love the touch.  Gotta do the brass, supa sharp!

[drventure]

That brass looks awesome, but the dark inlay is pretty damn nice too.

I'll throw another idea on your fire.

Etch the symbols into the glass. Use that liquid etch or sandblast technique.

Then, no mods to your wood at all, you just press the etched areas.

Finally, etch it on the BOTTOM of the glass and the top stays completely smooth for your cleaning pleasure!

[EightBySix]

That brass looks awesome, but the dark inlay is pretty damn nice too.

I'll throw another idea on your fire.

Etch the symbols into the glass. Use that liquid etch or sandblast technique.

Then, no mods to your wood at all, you just press the etched areas.

Finally, etch it on the BOTTOM of the glass and the top stays completely smooth for your cleaning pleasure!

I had a go at that. It gives the option of side lighting it too. I masked off an image on a piece of scrap plastic and went at it with sandpaper. The results werent fantastic... I'll look out for that liquid etch on google. I'm also looking at laser etching the veneer which could give me the option of quite fine detal or text like this

[SnaXen]

Very nice!!! 
I love it!   

 

[Rick]

As it would seem that with my own return to building my cab, I am also revisiting all of the cabinets that were in progress when I first left. As such, I have only HOLY CRAP!!! to offer. This is quite amazing, and looks better every new update!!!

[EightBySix]

Thanks for the nice words Rick  although they are a reminder of how long this is taking!

There are some updates, but they are under the hood at the moment...

Just got back from hols, and took my netbook for reading. Learned all about makefiles, c compilation, linking, etc and  downloaded the MAME 0.36 source (being on a data plan in another country focusses the mind) and finally managed to get myself a DOS compiled no-nag version using DOSBOX.

I'm also tweaking it to run the last played game if no parameters are supplied (I have a batch file hack to do that currently) so that it boots straight into a game (I dont have a front end - I have a back end.... you exit mame to choose a new game, which then become the default start up) and also to output to the serial port for displaying info on the LED matrix.

[nordemoniac]

I love this project!

I work in IT myself, and agree on the usage of hand tools etc. It's so nice for a difference to actually "see" what you are making.
However though, I don't have the time, and I have a huge table saw available at work, so for me it's power all the way.

I admire your sense of detail throughout the project, it really looks nice. I would have skipped the handles on the controllers, and rather have them automated like you did with the screen.

Can't wait to see your updates!

The touch-buttons is awesome. Please add some details on how they actually work. I'm thinking of doing something similar at work.

[EightBySix]

Cars have red lights at the back because that colour is more visible through spray and fog. I thought if I swapped green LEDs for red, they might shine through better. The LEDs that arrived seemed brighter than the old ones in the first place and they shine straight through the veneer, even when its not sanded thin. So that problem is solved, and I have some spare LEDs for another project one day.

Here's a video of me testing them out - check out the shine from the lights on the table:


Next I had to get them working so that I can send any string to be displayed. It turns out the chip I had cant address enough memory in one chunk to hold the font data, so I got the next model up. It's taken me forever to get it working, but I'm in a better place with it now. I can even program it whilst its still in the circuit, so I can write new firmware without taking the chip out, which is saving loads of time.



I needed to build a new circuit board. Seperate ones to manage the coin detector, the LEDs and the other stuff coing on was getting crowded, so I decided to put it all on one chip, on one board.

Heres the old one


And heres the new


It currently controls the coin detector, joystick inputs for menu selections, the outputs from the cap touch sensor and in the near future, a motor driver and RS232 port for comms with the PC.

I have to have the cap touch sensor code on a seperate chip because it has to be close to the sensor buttons.

The touch-buttons is awesome. Please add some details on how they actually work. I'm thinking of doing something similar at work.

Here is the chip that detects capacitance changes. The connectors to the left connect to the sensors (previous post) and the wires on the right go to the iPac (or in my case, another chip)

It works by measuring the time it takes to charge and discharge any capacitors (the hidden 'buttons') connected. When your finger gets near, you become part of the capacitor and that alters the charge time. It can have around 16 channels - but I only need 4: Pause, volume, exit and one more for 'future use'. They send a pulse which I pass to the main controller. It needs some tuning up, it's very sensitive to the size of the sensor and the length of the wires. PM me if you want the details, or I'll maybe start a seperate thread if anyone wants to make their own.

The pause and exit could have been connected directly to the iPac, but I wanted to intercept them to display some feedback to the user.

When you press pause - I display 'Paused' on the LEDs until you press it again.
When you press exit, it displays a countdown from 3 - you have to hold it so I avoid any accidental touches. On zero I send an exit keypress to the iPac which returns you back to choose another game.

Volume control is done by moving left and right on the joystick. It does nothing at the moment - I need a digital potentiometer to hook up to the existing manual control on the amplifier.

Here is a video of those controls in action.


The fade in/out took a while to work out, but I think it adds to the effect. The LEDs have 16 levels of brightness, and the lowest is just visible, so it looks like the image fades into the wood.
 
Almost there now. I'm going to move onto the motorised top next...
 

[markc74]

 

Amazing. That's it.

[emphatic]

OMG, that's frickin' cool! 

[drventure]

OMG, that's frickin' cool! 

Second that sentiment. Nicely done! 

[TopJimmyCooks]

Much respect.
 

[blueznl]

 

 

I just love that invisible dot matrix, incredible!

[ppv]

My shoes are soaked from all the drool on the floor. Very very well done sir!

[yotsuya]

Are you sure that's drool?

[Rick]

Amazing work. A-MAZING WORK.

[ppv]

Are you sure that's drool?

Well since  I am wearing a diap, errrr, Look! A duck!

[EightBySix]

Due to lots of counterfeit £1 coins here in the UK, they are designing a new one. I was annoyed because I might have to redesign my coin mech. Then I read that the new coin is due 2017, a long way off - but with current progress - who knows....

I had lots of holidays over Xmas and was hoping to get time to finish it. Ended up busier than expected and the free time didn't materialize. The work I did manage to get done was on my main circuit board - trying to add in the motor driver. Somehow I managed to screw it up - there is a short circuit on it somewhere and what with having packed it away over Xmas - I haven't found the determination to get back in the saddle.

So this is really a post to say I'm still here, and to kick myself into action. Lets see if I get done before I have to design for that new coin 

[drventure]

I SOOOO want to restore an old radio cab and embed leds like that all up and down the sides, sort of like an old style rockola jukebox, but where the side column lights are completely invisible (until they're not)!

Very nicely done! 

[AlienInferno]

Really glad you bumped your own thread.  Other then it being a very nice looking build I am planning to build a small bar to go in the corner of (what I hope to be) my game room/man cave.  Planning it to have a LED lit top that's interactive with people as well as the ability to play generic 8-bit type animations.  I was thinking your inlay controls would be great for it but your LED under the wood might work as well.  Lots of things to think about.

[jongunz]

Wow... All I can say.   

[rockyrocket]

Wow... All I can say.   

I agree, and how the hell did I miss this build?.

[EightBySix]

Probably because of the lack of progress since November 

I've been thinking about a way to fix my screwed up circuit board, and decide to cit off the new bit I was working on. This should help me diagnose where the short circuit is. I'm also thinking I should really keep the motor circuitry on a different board anyway, due to back emf and the 12V required etc.

So next task it to get the knife out and snap off the problem bit.

On a side note, I  came across a shop recently that 'engraves' wood with a laser, for personalised wine boxes and such. They said they would be able to cut oak veneer if I could supply a pattern in Corel Draw, which I happen to use at work. I think I'll get a more professional bezel done with the remaining veneer I have. Should also be able to get the cutouts  for the capacitive buttons done too, to let the brass show through.

No need to sand it thinner with my 'new' LED matrix either, they are bright enough without and gives a more diffused look.

[EightBySix]

I took the plunge and cut off the motor circuit. No luck, the shot circuit is still there, or at least I get no resistance between + and - which seems like a bad thing.



No difference! I must have screwed something else up.

So I'm asking for help. How would you go about tracking this down? Any tips?

[PL1]

Got pics of the underside and a schematic?


Scott

[nordemoniac]

Hey! Come back!
What happened?

[EightBySix]

Still here 

Got pics of the underside and a schematic?
Scott

When I was at university, we did a coding project to create a phone book database app, using Pascal and linked lists would you believe. The kicker was that when we had finished, part B* was to swap code with someone else and add a field.

The lesson was that it's really hard to modify code unless it's well documented and structured. I hit that problem with my circuit and code. Because I was learning as I went, and it started off simple enough to keep it all in my head, that sort of thing went by the wayside. When I came back to it months later - I cant remember what was where, and why.

So no - I don't have a schematic, but that's got to be the way forward. I'll make one and either etch or get a PCB printed and continue where I left off.

The shed project has taken my free time too, but at least I'll now have a better setup for projects, rather than making a mess in the house. The table actually helped with the shed too - a place to paint and glaze the windows - with suitable protection of course 

*(by the way - my code project used a config file to describe the fields - the next guy had an easy time of part B  )