Sunday, April 7, 2013

Baby Steps

The last couple of days I got my thumbs out and got to it -

1) The motherboard minus light board. Like Ben Heck says,
'Always build something you can take apart later'. I'm glad I listened, Ben!
The observant can see a piece of electrical tape on one of the shift registers,
which in this case means a dead shift register.
I've removed the motherboard from the machine and tried to fix it.

The removal went easier than expected as I've somehow forgot that I made the board removable as a single piece - despite it being a rather lengthy process of actually removing it.
Once removed, I noticed that two out of five prongs in the USB-connector were broken so at first I simply tried to wiggle the cable in place - which worked. But just as I was going to hot glue the cable in place the remaining prongs broke off as well.

I then figured I'll just replace the USB-port but accidentally broke a circuitboard trace instead. Doh!
But, luckily, after a while on google and the Chipkit-forum, I found out that the one I broke wasn't actually in use for the Chipkit so I'm still good to go. The port is ordered and will hopefully arrive in my mailbox soon. It says "reflow procedure only" but as my friend says - nobody remembers a coward.

Since the work involved removing the board is rather cumbersome I've decided not to reinstall the board until the lightboard is completed, which at the moment it's at 50% complete.

While at it, I took a peek at the broken MOSFET for the left bumper. I couldn't see any immediate problems with it but decided to replace it and the diode on the solenoid itself, should it be the problem.
Hopefully this will keep the left bumper up and running. If not.... then I have no clue what the problem might be. I'll probably use a solid state relay on one of the minor solenoids and use the freed port for the bumper instead.

2) Neat cabling is A to Z. Go the extra mile!
Unless it won't be visible. Then you can cheat. 
I've also attached the spinners,spotlights and switches cables now so all the visible switches and lights are looking good. Still the actual connecting left to do - but having shrink wrapped cables with no visible solder joints does a pretty big difference in appearance!

As for programming, not much has been done since the USB-port is broken, but I've started to look at the profile system I've been planing to do for a while.

Since it's a home game with a rather deep ruleset along with achievements I figure it'll be hard to finish it all in one go - so I'm looking at writing a kind of save game functionality. It will be possible to create and assign profiles for record keeping and competitions etc. 

More about this in a later post!

3) Early shot of the multi color LED circuit. A downer was that
there seem to be a limit in the LED itself so I cannot mix colors
by applying voltage on several pins. I'll probably have to emulate
the yellow color in software to compensate for this.  
Mr Bubbles has gotten a slight update with a tiny circuitboard for the multi-LED in his helmet, along with the servo now properly installed in his belly.

I've unfortunately decided to back down on Mr B's movement pattern and will let his disco moves become subject to a future mod (but the swinging arm and drill is still present).

I'm thinking it's better to get it up and running first instead of not at all, right?

Took a lot less time to write up the summary than to do the actual work, but that's the way it is!


  1. Hi,

    Just read your blog from start to finish, it is a great read. It looks like it has been a huge undertaking, I don't see anything "poor" about it either! It is only something that most of us mere mortals could only dream about. Keep up the great work.

    One day, if I ever get a chipkit, I might be hassling you with questions!


  2. Hi!

    Thanks for your kind words!
    It's been a huge undertaking, that's for sure. Even larger than I anticipated from the beginning, mainly because I had limited or no knowledge of pinball machine internals. So every step I've learned there's another set of steps around the corner. But I also set the bar pretty high for myself with the ambition that it should measure up to a professional pin.

    As for the building - I can see the end now at least... ;)

    You're more than welcome to hassle me anyday!

  3. That might be a lot of questions, its been a long time since I did anything Computer Science related!

    PS the outline of Dogmeat and the Lone Wanderer gave away your original theme straight away. No further hints were required! It's one of my all time favourite games too but please don't give me any further ideas to lead me into temptation :)