I’ve been working a lot on reviewing the code I wrote back in July and trying to get a hold on everything again. After a lot of thinking I’m pretty sure that the fixes I have made to the framework (Data retrieval and basic car variables) will be a hell of a lot more stable than it was in the past. I wanted to be sure of this because if something isn’t working right at this fundamental level, it could throw off everything I do from now on. I also came up with a new model for the entire system that I think will work quite well, utilizing a Server / Client relationship. The PowerBase is connected straight to a networked “server” that can feed as many client computers / monitors / projections as needed. Here’s a quick illustration:

The current run-down:
-Repaired PowerBase (New Resistor for Lap Sensor)
-Reworked Data Retrieval Algorithm to be more stable
-Data processing now runs on its own Thread:
  +Sends raw data to network clients over OSC
-Reworked car code to make use of all possible variables
-Working on rough HUD and text output for car variables
-Experimented briefly with race “recording”

Currently have access to:
+Reliable throttle (raw, smooth, and normalized versions)
+Both Lane and Brake buttons functional
  (No longer interfere with throttle numbers)
+PowerBase & Processing estimated Lap Times (Previous & Current)
+Reliable Lap Counting
+Approximated instantaneous and average speed (1:1 or 1:32 scale)
  (Likely needs tweaking)

TODO:
-Running Average Lap Time
-Running Average Speed
-Fastest Speed
-Fastest Lap

Will post some pics of the HUD output as it develops.

The first concept was to mimic the relationship of the car’s relative position on the track (in this case by drawing a continuous oval/spiral) and tie that in with the car’s current throttle. In this way we can get a sort of “histogram” of the entire race.

Oval concept using random data:

Using throttle input (changing colors per lap)

I tried something a bit different using strips of color, almost like a line graph. In this way it might be easier to visually distinguish a faster laptime based on the length of the color strip:

Testing Area, and pretty much the smallest track circuit you can set up with this kit

I set up a testing area in my room so that I could run some cars and still be close to my desk. A piece of plywood is pretty high-tech, I know..

PowerBase is powered-up and ready to unleash its magic

I found a power supply in my basement that works great for the time being. The Aux Port is really just a typical phone jack outlet, so I wired a phone cable up to this:

Don't mind the shoddy looking tape... It's a Prototype!

Underneath the electric tape is a small fuse which should prevent me from blowing up our precious powerbase if there is any accidental mishaps/crossed wires. This is a 9-pin serial adapter that is typically found on PC’s. However, Mac computers don’t have these kind of connections (only USB/Firewire) and need this Serial-USB adapter:

This plugs into laptop USB port

Basic sketch that retrieves and plots data in real-time.

Computer Controlled Slot Cars Anyone?

Also got the beginnings of a network/internet controlled car basically running (still buggy). Things are finally moving along!

Today, I continued some work on the simulation sketch. Currently it simulates four “cars” (rectangles) that have specific attributes (location, speed, laps remaining, race standing.. etc). The rectangle travels across the screen, simulating a lap completion when it reaches the far edge, and then cycling back to the beginning again. These “cars” are fed their speed data via an on-screen slider control. This allows you to modify the speed of the car in real-time much like what the physical hand throttle does on the track. The next thing to do on this is figure out issues such as lap timing and race standing, as well as a simple way to interface this sketch with others that will use the data.

Now for the REALLY good news!…

After playing around with the physical track & powerbase for a while, I figured it was time to get this thing to spit out some data. Although, I was missing a couple of pieces of hardware that would make the data stream more reliable (MAX233 Serial Driver), I figured “what the hell,” and attempt to see what it would give me anyways. I wired everything up… checked all connections… opened up processing… crossed my fingers… and flipped the power on.

The research on this thing finally payed off. I was seeing the numbers I needed to see. And after staring at the data for awhile, I managed to code a parser to organize the information into a usable form. A couple of hours of programming later, I now have instantaneous feedback on the hand throttle’s current position as well as a simple plot of its value over time. And I also decoded the elapsed lap time data that is triggered every time the cars pass over the finish line.

I have to admit… this is extremely cool and absolutely amazing, and only reinforces all that is nerd within me.

Pictures, Screencaps, and possibly video to follow…

Tape + A Single Layer of Bubble Wrap = Internationally Shipped Package

Needless to say, I was scared as hell at the very sight of this thing.
(please, please, please… don’t be broken…)

Exposing the Protective Layering

So Far, So Good.. And it's even the right one!

Everything looks good with the powerbase, and lets hope that everything is fine internally.

Silently preparing to unleash its glorious data.

Pretty thankful that they included this...

From what I can tell, this thing has an amazing amount of functionality… I really can’t believe that they stopped making these models. Instead of further developing the awesomeness that they had going for them they completely chopped these bases apart.

$%!# @#$#!!!..

Of Course it’s always something… Although, this is something that I could have foreseen, but didn’t even cross my mind until I was staring right at the alien plug. (Yeah no matter what you do derek… that thing isn’t going into the wall socket today or any other day…)

Although this isn’t nearly as big of a problem as say… trying to find a discontinued product in the UK, it still puts a small damper in things for the time being. But I think I might have a quick solution lurking in the piles of electronics in the basement…. Otherwise I’m on a city-wide search for a 12 Volt 2.5 Amp power supply.

More news tomorrow.

I coulda sworn something important went there...

You see… The “power base” that I have been researching which will eventually allow me to extract data has a pretty important piece of hardware that looks like this:

OH LOOK AN AUX PORT!

Pretty LCD...

Apparently, Scalextric decided to UPDATE their Power Base’s… and by UPDATE they really meant cut out every USEFUL piece of functionality and cut costs…(No AUX Data, No Lap Counting/Timing, No Racing Modes…Nothing) The really bad news is that they even decided to discontinue the older line of feature-packed 6-car bases, making these things extremely rare. One of the only bases I’ve found in the US is here: Part of a Digital Conversion Kit. Buying this may be our last hope.

Another idea..
Being somewhat knowledgeable in electronics, and with the OK from Steve… I cracked open the 4-Car Power Base that came in our kit.

Surgery Prep

Under the Hood

Hmmmm....

Wait... This Looks Promising... not..

I studied this thing into the night… the only thing that looked as though it could be hooked up for data (and something that I spent a lot of time trying to figure out) turned out to be something that almost every micro-controlled hardware has: An initial programming port… I confirmed this by looking up the spec sheet for the PIC 16F819 microprocessor that sits on this board. I also checked the rest of the pins on this but didn’t find anything very usable.

The only half-solution I see right now to get any kind of usable data (in this case only from the hand throttles) is to tap directly into the throttles themselves. The throttle lines (which are actually just analog values) could be spliced into another microcontroller (Basic Stamp 2 or Arduino) processed into digital and sent via a serial connection to processing… this is definitely the long way around.

Otherwise we should really look into acquiring an older version 6-car Power Base with built-in Aux Port ASAP.

Unfortunately it must soon leave.

It contains an SCX “Pit Box” racing set, complete with a whole track and 3 cars. However, it does not interface with the Scalextric set (The one I have been researching) that is on its way here.

Today, I also purchased the KeySpan USB to Serial adapter from Amazon.com – free 2-day shipping. I also secured a couple of FREE sample MAX233A Serial Driver IC’s from the manufacturer’s website – also free shipping. I love free stuff, and free shipping is awesome too.

**MORE TECHNICAL STUFF**
The MAX233 IC is the piece of hardware that converts the +5 Volt TTL signal from the Scalextric PowerBase to +10 Volt RS-232 signal that a computer can understand. I also acquired a nice little wiring diagram for hooking this up:

MAX233 to AUX Port Diagram

Still on the list of materials to buy:
-Serial DB9 Cable (Standard 9pin for computer)
-4 Lead RJ-11 Cable (Looks like a standard phone cable – for Powerbase)
-Other various electronics

It’s obviously incredibly hard to envision what this project is going to end up looking like in its final stages. (compounded by the fact that I haven’t even seen “the track” in person or know what it is capable of) But it’s still interesting to imagine the possibilities. I’m at a loss for what I will create visually and what purpose it will serve… Although, I’m sure this will manifest in the coming weeks when I begin to actually play around with it.

Still on my sound/audio mind binge from working with my senior project, I have a slew of ideas for little sound reactive processing sketches. Anything that deals with the hand throttles to cars crossing the finish line to create some sort of soundscape/musical piece, could end up being an interesting auxiliary element.

As for actual processing programming I might do in the near future: I may put in some time to set up a small sketch/program that acts as a “Track Simulator” that will be able to interface with any future sketches I make. This might make it much easier to share processing sketches and ideas without needing the actual Scalextric Track on hand. As for how to go about doing this, I need to do a bit more research and thinking.