I Dream In Infrared...

 F**king finally - opto's are online! 

Pardon the french, but I've been troubleshooting the optos for 6+ months without success, and yesterday the solution came to me lying half-awake in bed... It's stupidly simple, has a few downsides - but it works. 

After a few months of this...

1) Breadboard horror...

I realized (but not sure why) there was no power reaching the +3.3V line that powers the opto's. Come to think of it, pretty much all +3.3V devices are powered by the Chipkit already... hmm hmm. 

Turns out it was easier to create a new circuit on a breadboard and use a regular remote to trigger the IR receiver. This allowed me to see exactly what worked, and I could then apply the same method of troubleshooting on the board itself. 

2) Dusty horror....

Anyhow - I suspect a grounding issue (remember way back when I had problems with the +5V line not functioning correctly, or rather some of the MCP23S17 IC's would not work) so I simply took the same approach here. Basically, allowing the Chipkit to force the current the right way, since I suspect they're better at designing PCB's than I... 

And sure enough - we got opto's. 

3-4) Opto off and on. Tried and tested in the VUK, so it works
properly with a ball too and not just some giant hand covering it up.

Bloody brilliant! 

Pretty happy that I didn't had to make any (more) changes to the PCB and/or create external circuitry. This was also the last remaining hardware that needed to be solved, so onwards to creating the actual game!

Still here? 

What do you mean 'downsides'?

Well, yes. 

This change has pretty much rendered the fuses on the +3.3V and +5V lines completely useless as power will be drawn from the Chipkit (also) regardless. I have moved the screen to it's own power line now though, so worst comes to worst - only a few MCP's will burn to a crisp in case of failure. 

I hope. 

Operation Mother

So - finally got my greasy fingers around properly installing the motherboard inside the machine.

Still haven't got my opto's to work but at this moment I'll have to live without them. Will need to debug the circuit and possibly rebuild it separately in the future. 

Like most of the work on this build it's a bit of "one step forward, two steps back" since I was only going to screw the board to the backing plate. But... I forgot that the backing plate was made out of cheap fiber board so screws won't work - and - of course the cables didn't reach the intended position for the board.

So I did what any hobby engineer with(out?) self respect would have done; I cut a big hole inside the frame of the head.

This worked alright, but due to the placement of the intended cut everything turned out a bit crooked. Not that it matters much, since now it's done. But I know my future self will grin at this during any maintenance session, haha...

"Fun fact" - while checking out the playfield, it turns out most of the rubbers have cracked and need replacements. Again. But I guess I kind of was prepared for that and it'll have to wait until the game logic / game rules are completed and the machine is closed up properly.

Other than a few mishaps; the board is now installed and I didn't break anything in the process!

Installed and ready to be developed!

P.S, ignore the double vision display, there's
a small gap between the display and the panel at the moment. 

Holy optimizations, Batman!

Spent a "little" time optimizing the code base, along with actually trying to work out the kinks of why optimized mode doesn't work. I'm not all the way there yet, but the results so far are very nice! 

Note: The flickering apparent in both videos is mostly picked up by the camera only and isn't really noticeable IRL, and the refresh rate can be pushed up further. Just keeping it a bit "low" to avoid confusing myself while debugging the rest of the code in case it causes crashes/erratic behavior etc.

For instance - 

Here's a clip of SD-card videos running as fast as possible in the old code. 

Notice the slow motion (faked by frame-skipping previously, removed here). 

And here's the same clip after optimization. 

Compared to the old version, it's a lot smoother and I'm actually running the videos at 40fps here (faster than original 30). Notice the long blank space between the videos, where the old version barely finished rendering the first one when the second one was timed to start. :) 

Some crude counter increments:

Previous one-second count: 28402

New one-second count: 91857

Quite the improvement! 

Very satisfied with the results so far!

In case you didn't notice, I used two simultaneously running SD-animations (background & fx) during the second video. Works great and allows me to spice things up. #thumbsup 

And the cable mess have been mostly corrected now, all lights tested and working. :) 

Rolling with the punches!

What's this... two post within a year? Yes - it actually happened! ;)

Been using my new found determination and time to keep working on the machine, finishing up bits and pieces all over. To start off - flashers, GI and playfield lights are now soldered up and working correctly.

Well, mostly at least.

I ran out of cables so I had to order more.
And I kind of ran out of output ports for the lights, so I'll have to hook up some of them to the AUX-ports I made on the board. (phew). But it's all good! 

1) All lights, switches and solenoids are wired/soldered!

2) It looks very messy, but the cables are actually measured and the "exact" length required.
I ran out of zip-ties, but will of course tie everything neatly when the new arrives.

As for input during menus, I've gone ahead and made the switch "box" that houses the menu buttons. It will be painted and/or covered with a left-over decal, but I'll do that once I've finished the building.

When not in maintenance mode, the red button will lower volume and the green button raise it. Pressing the white button enters maintenance mode. During maintenance mode red/green goes left/right (use can also use flipper buttons), while the white button confirms and start button cancel.

3) The early draft of a control-box inside/behind the coindoor.
Basically - menu buttons and volume etc.

I've also adjusted the syringe to be a little more reliable as a pinball toy and replaced the tiny LED with a proper pinball LED-bulb.

4) I replaced the standard LED with an actual pinball LED-lamp.
No more worrying about accidentally applying too much voltage!

Software-wise I've optimized loading and SD-buffer creation to utilize hardware interrupts for SD-card loading. I've used this a while for DMD rendering, but now I've managed to get it running on the SD-card as well.

So the loops are pretty tight now, which are very nice.
For instance - When sending new data to the DMD I process switches/solenoids etc in the small gap the display needs to stay blank. This is not uncommon among older games which did processing between scanlines (more or less). Works a treat and pretty much doubles the performance.

And now I've done the same for SD-loading, where I basically start loading 512 bytes, and as soon as they're done loading I schedule the next batch and start building the buffer with the 512 bytes just loaded. The unpacking is needed to convert 2K (half-byte per pixel) to a DMD buffer (byte per pixel). The SD card is slower than building the buffer, so that's the reasoning behind not loading the full frame from disk. Previously I built the buffer after all 2K was received, but now I've shaved of a few milliseconds by doing it while "idle". Very nice! 

I've also started the rather tedious task of converting away from Arduino/Chipkit's "String" class. It's ridden with bugs, memory intense and in fact - won't even run when compiled as O3 ("optimize for speed")... There seem to be a problem with the hardware watchdog resetting during optimized compilations, but I can't get my hands around why at the moment. Considering the standard/built-in libraries won't even run properly, I'm not terribly sure my code is the culprit here...

But first, back to the 80's we go; hello, C-string.

A Ferrari-style pit stop!

Got around to do a little tinker on the board the other day!

* audience cheers *

First - had to recreate the development environment on my laptop. Took a little while, but well worth it in the end. And, naturally, the SD card for audio (and the reader) had given up and didn't work. (...sigh).  A purchase of a new reader and a format later solved that. No big deal. But annoying.

Still a bit of wiring to do, but slowly getting there!
Switches, flashers and global illumination is now done, and with a little luck I'm done with the playfield lights in the coming days (or so).

I knew about this before, but I may have to increase voltage for the lights. Currently 5V is a bit on the low side, as lights are quite dim. To avoid using a lot of constant power I also duty cycle the GI, so I figure 12V would be ideal here.

Luckily; there's not a whole lot that needs to be done - either cut the 5V traces and connect the existing 12V line, or move the drive cables to a 12V port on the board. This can be done "any time" so if the board feels too dim during actual play I'll adjust accordingly. :)

Stay safe!

"Woah" - Keanu Reeves

Can't believe it's been six months since the last update. :|

This will be another short and disappointing one, unfortunately.
I've had little to no time to work on my pinball machine, due to work, hobbies, life and family in general. And I've gone pretty close to burning myself out the last years, so I must take a hiatus from several projects for a little while.

I still expect the machine to be done somewhat soon, so bear with me. :)

Thanks again and check back from time to time! \m/

....still cables.

Waiting for cables.... damn holidays. :) 

In the meantime, enjoy this random photo (source unknown).