For some reason or another I was reading up on the history of Infocom recently. They used to make text based adventure games, aka Interactive Fiction. Remember Zork? Hitchhiker’s? Those were Infocom games.

I was pleased to find that while the commercial prospects of the genre are nill, there is a large and devoted group of people who develop games in some quite sophisticated development environments. One such IDE is called Inform and seems to be one of the most popular.

So, I had this idea. I’d make an Interactive Fiction game. The setting? Austin. At first I was going to make it a typical game (with puzzles, etc), but then I came up with another idea. Could this medium not also be used as a way to introduce people to the area? Photographs and stories are helpful, but an Interactive Fiction story would allow people to explore the world, kind of like a “choose your own adventure” but without any real end-goal.

You would be able to “walk around” and explore different areas. It’s combining the knowledge you might find in a Wiki with the exploration of an open-ended game. I like the idea of it being text based, because then much more is left to the imagination (like a book).

Thinking about it more, it feels to me somewhat like my holy grail of knowledge: The Hitchhiker’s Guide To The Galaxy. There is so much information out there, and we have cheap wireless devices, so why not make a Hitchhiker’s type guide? It could pull together zillions of things….maps, wikis, yelp reviews, and on and on. In the end, you’d have a crazy-complicated “copy” of the real world.

The web is kinda like that, but I see the web as a repository of data, mostly unorganized. Like a library with books intermingled. Imagine how hard it would be to find a book in a library like that? Maybe that’s why web searches seem to be getting more and more fruitless. We need organization.

I think we’re getting to the point where we need Google Walk and Google Bike. You know how Google (and MapQuest, etc) have driving directions? Well, I think driving directions are so 1990’s. Anybody can get in their car, put in $200 worth of gas, and drive two blocks to the grocery store. But getting around on foot, or bike, that’s another matter.

I know that Google started their Public Transit directions, which is pretty helpful, but that only goes so far. What about the walkers out there? In the Chicago area (excluding some suburbs) you have sidewalks everywhere. Every street. Everywhere. You really don’t have to think about whether you can get somewhere on foot, because you can. The downside, of course, is the car traffic, the crappy weather, and so on.

I didn’t realize how much I took sidewalks for granted until we lived in Puerto Rico, and now Austin. In PR, you only had sidewalks in the main town areas. In Austin, it’s pretty hit-or-miss. There are bunches of areas without sidewalks, which makes taking walks a challenge. We’ve spent a good deal of time just finding safe places to cross, quieter roads, etc. Sure, we have the wonderful “greenbelt” walks (ex. Shoal Creek, near us), but you have to get there first.

I’d love it if I could pull up a Google Map and say, “I want to get to this bookstore” and have the Directions tell me where there are sidewalks, where it’s safer to cross the busier streets (a bonus), and estimated time.

Obviously, it would be a pretty big undertaking, but they already have the data, either in overhead satellite images or the notorious “Street View”. (I’ve actually used Street View to determine if there were sidewalks in an area. It’s not perfect, but it helps.)

Perhaps easier would be Google Bike, which would cover the bike lanes in a city. This should be considerably easier to do, as many cities already have Bike Routes marked (though often neglected). The data are somewhere, and dedicated bike lanes can be seen in satellite images. In fact, it would probably be very similar to what they had to do to get Public Transit Directions working.

So, there’s another project for a budding entrepreneur out there. It sounds like the perfect “mashup” between Google Maps and personal knowledge.

I could have gone with a microcontroller on the maze table motor controller, but I opted for using discrete components instead, with a little help from a L298 H-Bridge chip. And H-Bridge is a circuit which allows you to reverse a DC motor. The chips make things easier by handling some of the inverter and “AND” logic for you. Plus, they are built to handle nice sized inductive loads, which some low-end transistors might have a harder time with.

Here’s a photo of my completed controller board:

The bottom part (from top to bottom) has a 2N3906 PNP transistor, a 10K resistor, then a small 1N914 signal diode, and finally a single pin header which will be connected to the joystick. Why the PNP setup? Because the Atari-style joystick takes a direction/pin and ties it to ground. So, the emitter (left part) of the transistor is tied to VCC (+5V) — those red wires — and the base (center) goes to the switch. When the switch is pressed, the transistor puts +5V (roughly) at it’s collector (right part), which is then sent to the H-Bridge chip.

The signal diode are there to prevent power from going “backwards”. For my setup, they probably aren’t needed. However, if I was doing an “OR” situation (ex. wanted to drive two motors at once), then there would be more diodes, in a more complicated setup. Check out David Cook’s extremely helpful article here: Controlling Robots With Atari Joystick. It helped me a lot, though my design diverges with the H-Bridge chip used (I used a more powerful one) and how the motors get driven (I’m not trying to get a robot to drive “forward”, so my stuff is easier).

Okay, above the transistors is the L298 H-Bridge chip. It can control two motors, forward and reverse. Once you get how these things work, they are very easy to use. For each motor, you have two control lines. Let’s say Input 1 and Input 2. If you do Input 1 High and Input 2 Low, the motor goes one way. Do the opposite and it switches direction. There is also an “enable” pin which must be held High for power to be supplied to the motor.

I like the L298 because it can handle some mean load (40+ volts) and it has two power levels. One for logic (running the chip), up to 7 volts. The other for motor power (up to 40 or so volts).

On the downside, it is mean for a PCB and not a perf/strip board, so the pin-layout is a big pain in the butt. I got around this by putting female headers (sockets) and by “twisting” the pins a bit. It means that there are 8 pins in one row and 7 on another (it’s a 15 pin chip). It can be very confusing, so be careful.

The PNPs collectors feed to the appropriate “input” pins on the L298. They also, through more switching diodes, trigger the “enable” pins on the chip. You must “enable” and input, otherwise you won’t get juice out. (This is by design, as it allows you to shut off motors without cutting off inbound logic. Think of it as a un-mute button.) Again, take a look at David Cook’s site. He does a good job explaining everything.

Above the Bridge you have the output area. This is where I have the output jack connections, inbound board power connections, status LEDs, etc. Nothing overly exciting, though I’d recommend this: Put status LEDs everywhere. I have an LED for logic (5V) power and another for motor (12V) power. I’m also thinking of adding some on the PNPs and maybe the output pins (to indicate power and direction). It may seem like overkill, but this is going to be re-used in the future, and having those indicators saves a LOT of time when trying to debug problems. Think of it as “breakpoints” in electronic circuits. (They can also save your life when it comes to power supplies. A simple LED alerted me to a “hot” AC connection that could have zapped me. Thank you, 5 cent part.)

After all that fun, and some heartache too (stupid me wired base to input, instead of collector to input), I got the darn thing working. The maze table now moves around with joystick control. The only problem is that the marble doesn’t like moving around my prototype board. I’ll have to try another material, but the concept is sound, so I’m moving forward.

Here’s a shot of my mini milk-crate joystick. I used a small plastic crate from the dollar store. In fact, the same kind that I used for my fume extractor.

Because I wanted to use this joystick for other projects (you never know), I wired it up using the “standard” (and ancient) Atari 2600 pinout. It uses a DB-9 connector, like the Atari (and most every other 1980’s computer). I put the “fire” button at the bottom, in the middle, for the benefit of the leftys out there.

I love these little $1 crates. They aren’t the strongest thing, but they make whipping up something easy. Plus, you can see through them, lots of room, etc. And, worst case, you ruin a $1 crate.

At the bottom of the photo, I’ve got a hookup and bare wires for connecting to my control board. The socket protector / strain relief cost more than the crate.

Here’s an inside view of the crate joystick:

The careful observers out there will notice that I color coded my wires the same as the original Atari 2600 joysticks. At least, as best I could. I didn’t have any orange (for “fire”) or brown. So red and yellow will have to do. Because my joystick config ground the switches when activated, this setup will work with any classic computer or game system that uses DB-9 connectors (Atari 2600, 5200, Atari Computers, Commodore Computers, etc).

Notice that I only used a jack (female) on my crate. This allows me to use any sort of M-F extension cables that I want. Much better than a fixed / hard-wired setup.

One of the things I don’t like about the Olimex MOD-MP3 player is it’s need for 3.3V. It’s not a standard “homebrew” value (we like playing with 5V or 9V). While they do have a 1.5 AA battery and booster on the board, it seems to chew through that battery pretty quickly.

So, I knew I had to build a 3.3V power supply. Luckily, National makes a great supply chip, called the LM2937ET-3.3. It’s much like their other regulator chips: Give it juice, and it spits out nice clean regulated voltage.

Since I already built out a 12V supply for the radio (to drive the Audio Amp, and CMOS logic), I figured I’d dump 12V into the LM2937 and let it handle the rest. It’s a newer chip, so it’s better at handling those drops without dumping too much to heat. (The input voltage is rated up to 26. Quite a range.)

So, now I have a 12V supply and a 3.3V supply and the Olimex runs great on the external supply. No more batteries. Here’s a shot of the supplies:

At the left you see the (dinky) transformer from the original radio (it was AC powered). I kept it “just in case” and I’m glad I did. It gives enough power (about 18V) to drive the LM7812, which gives me clean 12V. The middle board is the 12V board. Look at that giant cap and heat sink. I’m a big believer in making power supplies robust. If they blow, all kinds of damage could be done (including risk to life).

At the far right you see the new 3.3V supply using the LM2937-3.3. The output should dump to a 10uF (or greater) capacitor, to give the design some additional stability. I went with a chubby 100uF I had on hand. Super overkill, as that bugger is rated at 200V. No risk of burning it out!

In general, you want to have big, high-voltage rated, caps in your power supplies. They help “even out” blips in the power and help provide rock-solid clean power for your downstream components. They also help with handling inductive loads (like motors). No big loads here, but better safe than sorry when it comes to a power supply.

The bottom board is the Olimex MOD-MP3 player board, sans AA battery.

Next up, I gotta get that rotary encoder circuit working. That’s the only major part left before I can put together all the pieces.

Here’s a couple of photos of the final bat sign. First up are two shots of the control box, sitting on top of the power pack:

As I mentioned previously, we re-purposed a second hand “data switch” (for switching VGA monitors). Above, you can see that box, with the power underneath. The cool power box? That hold 6 “D” size batteries, which give us 9V and plenty of juice. It’s an old Maxtor hard drive case that was just dying for a new purpose. Now it’s a 4 pound power pack you could run over with a truck.

Here’s a rear view of the controller. Here you can see the DB-9 cables connected. We used DB-9 because the cables are cheap, and easily found. So, the control box can sit 6-15 feet from the sign.

The power interconnects are 1/4″ mono phono jacks, like those used for electric guitars, etc. They are rock solid and give a nice retro mechanical feel. Not standard power connectors, sure, but they do the job.

Here’s a photo of a very proud Evelyn with her sign. It came out really really great, and it has a very “polished” look. Even the cables in the back are covered by a back panel. It’s built to last.

As you may know, Evelyn has been working on a Bat display sign. This is a “eye catcher” we’ll use to help draw people to our booth. After a lot of work, she came up with a good way to matrix the LEDs, and it’s very close to completion.

After many discussions, we decided to make the control unit modular. That way we could use it for other signs. To do this, everything is plugged together to a control box (versus being hardwired). It took more time to do this, but it means a more flexible design, and it’s more “bullet proof”.

In the end, we decided to go with standard D-SUB 9 pin connectors. They are pretty easy to work with and very common. (They are those old “serial port” connectors you see a the back of older computers; pre-USB.) Anyhow, we needed a project box and found one at are local second-hand shop. And old VGA switchbox, made of metal. The beauty of it is that it had most all the right hole already drilled.

Here’s a front view of the control box:

The jack on the left is a 1/4″ “audio” jack. We decided to use this for power, since it’s jumbo-sized, and we had the parts on-hand. We replaced the old rotary switch (and guts) with a toggle switch. It toggles between “on”, “off”, and “program” modes. There is a small status LED to the left of the toggle to let us know that the box is working. The whole unit is sitting on its lid.

The only hole I needed to drill was for the 1/4″ jack. Since it’s thick sheet metal, that process was a bit of a pain in the butt. Luckly, we had recently purchased some new drill bits (and got our big drill out of storage). I cleaned up any burrs with a Dremel and a diamond bit.

Here is a rear view:

Isn’t it nice when an old piece of equipment works perfectly for a new project? The original box had three DB-15 high-density connectors, which are the same size as the DB-9 we’re using. No cutting, thank goodness! Plus, they supplied the hardware to mount the connectors.

Finally, here is a top view into the unit:

At the bottom, you see the three DB-9 connectors. There are three sets because we have the unit wired in a 3 x 8 matrix. Three columns (wing, body, wing) and 8 rows (sets of LEDs in the sign).

At the far left is the battery for the Arduino. We kept it’s supply separate, in case we need to drive LEDs off different supply voltages.

Next you have the stripboard, which has a Boarduino on it. That’s a version of the Arduino from AdaFruit. It’s small and easy to work with. Evelyn has it plugged into some female headers, which are then soldered to the board. This allows her to pull the board out, if necessary. The Boarduino has a programmer connection on board (between the blue and yellow DB-9 connections), so it can be programmed without being removed.

To the right, the rest of the board has the PNP (columns) and NPN (rows) transistors. After mucking around, and having much trouble with, smaller transistors, I suggested we go crazy and drop in some TIP107 and TIP102 transistors. They are really super-overkill, as they can handle 100V and 8A, but what the hell. They worked perfectly, and we don’t have to worry about overloading them.

Finaly, in the upper-top-right you see the back-end of the toggle switch, status LED (with lots of hot-glue), and the 1/4″ power jack.

What you don’t see is a little cheat-sheet I wrote up, which I wish more people would do: It’s a document, pasted to the inside of the cover, which lists the color codes, pinouts, and so on. It will allow us, in a years time, to crack it open and not have to guess as to “what does what”. Kinda like the old schematics that TVs and Radios used to have — when you could service them on your own.

And here’s the final bat sign, with the whole “cave” cutouts.

In addition to the pink LEDs backlighting the bat, we have three super-bright white LEDs located behind parts of the cave. (They aren’t on in this photo.) These give a really cool “lightning” effect and are a great eye catcher. We’ll make a movie of it and post it up. It’s quite impressive.

Update: Here it is with the “lightning” effect:

I’ve been dealing with two product recently which have been driving me up a wall, and for simple reasons. Here’s the first:

The OXO Pepper Grinder : Designed By Oxen

The below photo is of their flax grinder (why you’d want to grind flax at home is a whole other question). I couldn’t find a photo of their pepper grinder, maybe because they were so ashamed of it.

I picked up mine at a second-hand store, and now I think I know why. For a while it worked well, and I really liked it. It was handy, a good shape, has a nice ceramic grinder, and so on. But there are two big problems with this grinder. First, you have to tip it upside down to get it to grind (so the glass is facing up). You are seeing this more and more in “high end” grinders. That’s okay, I guess, but it feeds the FATAL FLAW: The sloppy, unreliable, locking mechanism.

See that big button on the side of the grinder? That’s the release button, that allows the black grinder part to separate from the glass container. You press it under one condition: To refill the grinder.

The problem is, you have to hold the glass and twist the black part to grind (taking off the colored cap first). You can see where this is going, right? It’s unusually simple for a finger to slip and press that button. Then, thanks to the “upside down” design, the glass bowl unlocks, and you have a 1/2 cup of peppercorns scatter throughout your kitchen.

About a week ago I had such a misadventure while trying to grind pepper over eggs. Peppercorns everywhere. It was the first time it happened, so I thought it was a fluke. Well, I spent a good part of Saturday cleaning up the Kitchen, and picking up the million peppercorns (after destroying breakfast). And I carefully cleaned out the grinder.

All seemed well, until yesterday, where I got to not only dump an entire refilled container of peppercorns into my sloppy joes, but also got the treat of burning my hands in the process, desperately trying to prevent an abundance of peppercorns from destroying dinner.

Of course, I followed the time honored Nelson tradition of crappy tools: I smashed that fucking thing into the garbage. It was a pleasing sound when I saw it hit a beer bottle, causing the grinder to  crack in half. Good riddance.

My thoughts to the bonehead who designed this grinder: Never, ever put a release button close to a holding surface. That’s stupid. Second, that “neato” flip-it-upside-down-to-grind idea is turning out to be pretty dumb. If the cap of my old wooden William Bounds grinder falls off, all I lose is the cap. The pepper can go nowhere. If your gigantic pepper container goes loose, you get peppercorns everywhere. Brilliant!

Also, a big cockpunch goes out to the moron who decided that making the container out of regular glass, instead of tempered, was a great way to save money. If that container hit the floor, I would have had shards everywhere.

Dremel 7.2V MultiPro : When Tools Are Designed By Interns

Meet the Dremel MultipPro, battery powered version. We picked this up a while ago, as we thought it would be handy to have a Dremel which didn’t have a cord. (Important for our tiny, power-lacking, apartment.)

I’ve typically found Dremels to be pretty good tools. I’ve had a corded one for ages, and it never gave me problems. The primary exception is their utterly annoying collet system for holding bits. I understand that collets are good for highspeed and accurate work, but come-on, this is 2008. Come up with a design that doesn’t take me 2 minutes to change a bit. (I know they have a chuck accessory, but that could be included, not a $10 add-on.)

Anyhow, let’s take a look at this tool. First, it feels a lot cheaper than their other tools. Mostly lightweight plastic. Second, and more annoying, is the horrific power switch. It is too hard to swich, it doesn’t stay in position, and there are too many instances where you think it’s “off” but it’s just barely. Very dangerous. But that’s not the worst part. The worst part is, like the OXO, the battery release.

See that ribbed oval-shaped blue tab toward the battery end? That’s one of two battery release tabs. (You have to release the battery to charge it in a wall charger.) See how it, like the OXO, is EXACTLY where you would place your hand? And guess what happens? Nine times out of ten the battery unlatches RIGHT IN THE MIDDLE of your work. This is no fun when you have a 10,000 RPM diamond bit cutting through something. I’ve fucked up more than one piece because of this idiotic battery design.

Now, normally, you might be able to hold the tool closer to the bit. That’s why there is a rounded “finger stopper” area near the collet. The problem is, the tool is bottom heavy (toward the battery, at the one end). So, you end up shifting your hand position away from the bit (losing accuracy) and toward the battery (increasing your chances of unlatching the battery).

I honestly can’t think of one instance where the battery hasn’t fallen out on me while working. I’d wrap the thing in electrical tape to hold it on, but I can’t, since the battery has to come off to charge. What a fucking pain in the ass. This tool is riding a razer edge toward going in the garbage. One more slip up and it will get kicked to the curb.

A Wrap Up

Both of these product show tools gone bad. What I don’t understand is why two companies, known for making good tools (be it kitchen or workshop) can come up with such clunkers. Did they let the college interns design them?

Perhaps more concerning is how these tools ever got out of testing. Didn’t ANYONE say, gee, the balance of this tool is off, people might disconnect the batteries / unlock the lids? Didn’t ANY testing occur? Christ, it takes about 10 minutes with the Dremel to realize that the battery “locks” are in probably the WORST place to have them.

The frustrating part is knowing that these tools should never had made it to manufacturing, let alone in consumers hands. There is no reason why either of them should have the flaws they do. The problems simply aren’t subtle, they are glaring mistakes that should have been caught by at least a dozen people along the line from product concept to manufacturing. Didn’t ANYONE say, or have the authority to, stop the process?

Are we so wrapped up in throw-away junk that we can’t design anything properly anymore? I don’t think so, but some of the current products get me awfully discouraged.

I just got the joystick & button parts. Here’s what the set looks like:

I bought X-Arcade’s “Arcade Bundle” set. You get 2 joysticks, 18 black buttons, and 2 Player One/Two white buttons, all for $35. Not too bad, especially since all of them use nice mechanical switches. The joysticks are quite robust, too. Real arcade quality.

For the Maze Table project, I’ll use a joystick, the Player buttons, and maybe another button or two. That will leave me with a spare stick and about 18 buttons. I wonder what I can do with those…

Update: Since I have the joystick, I might as well finish up the playing field.

Above you see the 15″ x 15″ playing field, with neon colored pipe cleaners as the maze edges. I used Loctite PowerGrab (similar to Liquid Nails) to outline the maze, and then pressed the pipe cleaners into the adhesive.

If you are doing a small project, and don’t want to bother with a caulk gun, then get the pressurized can of PowerGrab. It’s self contained, with a little lever to dispense the adhesive. It costs a premium over the regular stuff, but it’s great for small projects like this and is very easy to deal with.

During our most recent parts order from All Electronics I picked up about ten of these:

They are solar cell assemblies, about 3.5″ x 2″ in size. Originally, they were used inside those outdoor solar path lights. It’s an interesting unit, because it has the cells, two rechargable batteries, three red LEDs, a light sensor, and the charging circuit (very simple, a diode, two resistors, and an NPN transistor). In quantities of 10 they are $2.50 each (All # SPL-05), which is probably less than the cost of the solar cells alone.

All Electronics sells a couple of versions of this unit; this one being the most expensive. I’m guessing it costs more because they actually work. After a day of charging, the lights stayed lit all night (they are still on now, 14 hours later).

So, now I need to figure out a project to use these in. Some sort of solar powered mobile? A slow moving explorer robot? A power source for a Zig Bee based monitoring station? What do you think?