Monthly Archives: May 2012

Disaster boards received

The boards for Disaster were received yesterday (5/30/2012).  The gerbers were sent to the factory on 5/14/2012, so that is about a two week turn even using the slow boat from China.  (The original submission was on 5/10/2012, but the boards were rejected because it looked like multiple designs.  The back and forth took about a week until the approved the designs.  I need to remove the silkscreen on the back of the boards so it doesn’t look like individual boards.  The ground plane pours make it easy to figure out where to cut the boards.)

Two or three week turn is incredible for the price I paid.  Itead Studio is now my favorite cheap board house.  I look forward to using them frequently in the next couple of years.

Last week I populated a surface mount board using a hot plate and solder paste.  It went surprisingly well, and I only had two solder bridges because I had too much paste on the pads.  I’m sure that the process will go a little better the next time.  I need to remember to layout out all the components before hand because I dropped approximately 30% of the 0805 sized resistors on the floor around my desk.

As promised, I’m going to throw up the schematic for the open pinball boards.  Since I don’t know how to put up the Kicad stuff easily, I’ll just throw up the schematic itself in a PDF format.  At least other people will be able to read it.

Next up is to populate one of each of the individual boards, and then start testing them.  We are trying to embedded a motor in a board for a project at work, so the solenoid driver might be useful to drive that circuit.

1000 Schematic


Pinball Night 5/24/2012

Well tonight is pinball night.  Flash is waiting for a new processor to show up, so we won’t be doing much work on that.  Firepower II has an issue with the registering of the orbit shot, so that will be the top priority.  We also got a new flipper coil at the Allentown show so we can see if that makes any difference in the right flipper.  There are a couple other small issues with Firepower, so since we will have it opened up, we can try to fix all of those irritating things.  Gulf Stream is basically ready to be put back together after getting a clear coat.  Mark has probably done more on that machine than I have at this point.  It is almost a year since we started restoring that guy.

Sold a weight set out of the basement so now I can move some stuff into it’s place.  That should get the shuffle bowler out of the shed so that I can start restoring it.  It means that I can also take home Olympic Hockey from work.  It is currently just sitting there and nobody is using it.

Just received a note back that the Disaster boards were sent from China.  It should be another two or three weeks until they get here, but that isn’t the tall straw at this point.  I have a lot of work to get a version of code ready to run on the main controller.  I also need to place an order to get the parts to populate the boards.

Today at work we will try to populate a surface mount board.  Mark’s bringing in a hot plate, so we can see what how populating an SOIC28 goes.  It seems pretty relatively straight forward.

Disaster Boards Ordered

The board layout was checked, and I verified all the footprints last week.  Should have taken more time to review it, but I thought that I would just roll the dice and assume that any mistakes could be corrected.

I ended up sending the board layout to  I ordered a set of boards from them for work ($48 for 10 cm x 15 cm, then $30 for fast DHL shipping for a set of 5 boards).  The work boards just came in today and they look great.  Got the first one up and running.  The total time from order to boards in my hand was 13 days.  Incredible.

With the Disaster boards, I had some more issues.  Basically the layout consists of four solenoid controllers (each can drive eight solenoids), five inputs controllers (each can handle sixteen inputs), nine LED controllers (each can drive eight LEDs), a main controller, an RS232 interface, a power input controller, and four individual LEDs with mounts.  It is all slammed together on a 15 cm x 30 cm sheet.  I put silkscreen lines between each controller, and I got caught for panelizing boards.  Now I understand that they don’t want to collect divergent designs and put them onto a single panel, but this is one design in my mind.  It was my bad for adding silkscreen to the bottom of the board to indicate this, but live and learn.  (Oh yeah, I also separated each controller into a separate ground pour.  That probably made it look like multiple boards.)

When I tried to correct this two nights ago by sending new Gerbers, I ended up sending the same original Gerbers as before.  I tried to correct it last night, but the factory had already started the boards, so I guess that they accepted the design.  I should find out tomorrow morning if the design is in process.  Cost for 5 sets of the 15 x 30 panels is $110 + $9 to ship to the US.  That is just crazy low prices.  If this works out, I will be singing the praises of ITEAD Studio.  This means the non-populated board cost for a pinball machine is $24 in quantity 5.  That gives me $76 for parts to hit my target.  Seems possible.

Allentown Pinball Show 2012

Mark and I made it to Allentown.  We drove down on Friday night, and stayed somewhere in NJ.  Ended up pretty nice because we found a plaza that all the restaurants were BYOW and there was a liquor store.  Mark and I grabbed a four pack and enjoyed the warm muggy night while eating our supper at about 9:00 pm.

I went to the show expecting to find out what people were paying for pinballs, and seeing what the possibilities of selling a pinball at a show were.  There were supposed to be about 200 free play pinballs there, and it seemed like 80% of the machines were for sale.  We hit the show about 9:15 and played a lot of good games.  We mostly focused on Williams machines, and some of the newer DMD games.

My take on most newer pinballs is that they all have a really similar feel.  We played T3, Tron, LOTR, Spiderman, bunch of other games, and I don’t think I could really tell the difference.  Most of the shots were the same between games with not much different than some theming changes between them and maybe one toy.  Don’t get me wrong, they are a blast to play, and I’d love to own any of them, but I only want to own one of that type.  Why own any others.  I did get a chance to play a round of Medieval Madness which strangely enough had almost exactly the same shot layout as these machines.   All of them are great “shooter” games, but there just didn’t seem the be the breadth of different styles as the old games.  Of course that being said, if I owned one of these machines, it would probably quickly become my go to machine for playing most frequently.

We probably played a couple hundred games of pinball.   All different varieties and different ages.  It was really fun.  It did make me think that some of the ideas that I have for Disaster have not been done before.  At one point we kept playing games with shaker motors, and it simply seemed like somebody figured out how to install a motor and everyone needed to add them to their machines.  Most of them didn’t add to the game play.

I was looking for a playfield that I could use to test my solenoid driver boards.  Found an Atari playfield complete and in great shape for $50, but somebody had already paid for it.  I ended up focusing on a Shaq Attack playfield with most of the stuff but missing the drop targets, and the rotating basket assembly.  It had all the wiring and was in good shape.  The guy wanted $100 but I ended up getting it for $60.  It is also nice because I can look at a modern playfield which, judging by the wiring on the bottom is no more modern than the early 80s.  It continues to amaze me that pinball architecture hasn’t been updated since then.  Who pays the guy who spends a 3 days wiring a single machine.  Maybe that is why machines are so expensive.

The drive to and from Allentown was long, but I’m glad we did it.  I just found another pinball show up in Ottawa in September which is only four hours away.   That might make a nice weekend trip.  Maybe I could sell a couple of machines up there.  I’m doubtful I can get Disaster running by then unless I start working a lot harder.

First cut of schematic is done

Just finished the first cut of the schematics  and sent them off to a free DFM checker to take a look at them.  I need to verify all the footprints and do a sanity check on it, but it looks pretty good at this point.  The end board consists of a couple different subsections including solenoid driver boards, LED lighting driver boards, input boards, a main controller board (the brains of the pinball), and a power supply board.  Since I had the extra space, I also tossed in a debugger board to interface with the other smart cards.

Basic design is as follows:  main controller board talks to LED light boards using the SPI bus.  Simple, and the processor I picked (MCF52212) can do this in a state machine, so no wasted cycles to update these LEDs.  Main controller also talks to input boards/solenoid driver boards using an asynchronous serial port.  (RS232 but at 3.3/5.0 volt levels).  Each of these boards is daisy chained together so that the processor can “discover” the boards when initializing.  The solenoid/input boards each have a MC9S08SE8 processor on them to either fire the solenoid, or collect the inputs.  The main controller sends commands to these boards over the serial link, and the responses are daisy chained together, and returned back to the main controller.  The scheme was designed to minimize the wiring.  Oh, how I hate wiring.  It should make for a very flexible and clean looking back of the playfield.

Each solenoid driver board has inputs for each of the solenoids, so that they can be fired very quickly for the pop bumpers/kickers.  The small processor collects these switch presses and sends them back to the main controller when requested.  That way all of the real time stuff happens locally, but info that affects the score, can be collected and sent for “batch” processing at the main controller.   Serial communications support debugging commands such as firing solenoids during test modes.

Input driver boards collect inputs from switches and present single edges to the main controller.  They get rid of all the bounciness of the real world.  Basically these boards are very similar to a smart PIA in current pinball machines.  I tried to make this part out of a Xilinx FPGA, but I just couldn’t get it any cheaper than putting a small $1.50 processor on there.

I now get to start adding up the costs to see if the BOM is coming in below target.  Target for the boards is $100.  It’s going to be close.  If I could do this stuff in any quantity, it would be easy, but building stuff for a hobby means you don’t get to use anything more than quantity 10.

All of the PCBs have been done in Kicad.  I’ve been very impressed with the amount of tweaking that I can do in the program.  I basically made each board as a single board, and laid it out.  Then I did an overall plan to put all individual small boards onto a single PCB.  I created a new schematic and put all of the sub boards in separate sheets in the schematic.  (For some reason, couldn’t use a relative link to the old boards, but made a copy of the schematic sheets and boards into the new larger project.)  I linked all of these together, altered the reference designators so I could have multiple copies of each board, and then copied the board files into the end layout.  It all worked fantastically well.  I’m sure that I could not have done all those things in Pads.   Kicad is very intuitive for me.  It seems like it was written by programmers.

That’s all for tonight.  Hopefully more later this week or this weekend.  Off to see the show in Allentown on Saturday.

New RAM chips are here!

Well the new 5101 RAM chip came in, and it seems that Flash acts no differently with the new chip installed.  Very disappointing.  I think we are going to need to get the test PROM working to really debug this board.  If we hook the logic analyzer up to it, we should be able to see the code executing.  (Amazing easy to debug since every bus cycle is external to the processor.)  Of course, I would give anything to just hook a BDM debugger up to this thing and quickly see why it isn’t getting past the initialization routine.  Oh well, tonight is pinball night so hopefully we will have more info then.