Archive for January, 2010

Ph’nglui mglw’nafh Remoc R’lyeh wgah’nagl fhtagn, or, Everybody Loves Remoc

Sunday, January 17th, 2010

At the end of January I drove back to the city of heavenly taquerias and got jiggy with installing new brains in Remoc, just the cutesy wootsiest Elder God you could ever hope to meet!

Our boy assumed this position for many hours. Quoth the security ladies at the front desk, “Your Monster is all Drunked over!”

Here’s what the sensors look like in vivo. The little wire goes to a sheet of copper tape which is adhered to the inside of one of Remoc’s surfaces where he’ll be sensing touch (for instance, his finger — you’ll never guess what happens if you pull it). These plates are all of different sizes and shapes, and of accordingly make for different signal strengths on the output. They are also pretty close to one another sometimes and it certainly seems from looking at the ADC readings like there are some irritiating interactions between some sensors. If I did this again, they would each have an enable line and be polled sequentially. But.

The little boards get stuck down somewhere convenient and close to the tape, and then the more-or-less DC sensor signal is shuttled back through a cable.

Finally, the guy who sculpted Remoc managed to set his entire body cavity on fire shortly after all the copper tape and wiring was installed. This adds a real “wild card” element to the sensor system which keeps it fun!

Anyhoo, after a long install, he was back up and gibbering, and there was much rejoicing!

[Ed note: since this time, word has again arisen from the West that the cultists are stirring. It is likely this is not the last time we will sojourn to the Comer, dear reader, or as I like to call it, “Baby Boo Miskatonic”]

The Joy Demon Cont’d

Sunday, January 10th, 2010

So sometime at the beginning of 2010 the sick children of Chicago set up a fuss looking for their monster again. You could hear them all the way from Brooklyn. Again, my guilt was heavy. Again, I made some stuff.

An introduction of what Remoc does is in order I guess. He’s basically a bigass toy that senses when little kids touch him in different spots and plays various games with them. He laughs, he cries. He may or may not be better than Cats. He also goes to sleep at night, sings songs, and has a weird interactive thermometer. He farts a lot. When he behaves, he’s kind of fun.

His memory and play pattern live on an SBC designed by my buddy Todd Squires which we used at the old toy company and affectionately call the toybrain (version 4). The TB4 was fine.

There was no real way to salvage most of the rest of Remoc’s old brain. There was a crappy class AB audio amp I put in which got way too hot, his touchsensor circuits were noise prone and also temperature sensitive, and his LED supply tended to go out of regulation when too many lights in the thermometer stayed on, and he got confused easily about time-of-day stuff if you turned his supply off. His eyeballs were light bulbs which burnt out (that was a committee decision, but). None of this was good.

His new brain boards (above) dealt with all this stuff. 2010 saw Remoc get new MOSFETs to run all his lights, a new audio amp, and a proper RTC with a ginormous battery for backup. More importantly, he got a bunch of precision opamps and a multichannel ADC to handle input from the touchsensors.

The touchsensors were actually fun to make. They’re an AVR which generates a crystal derived square wave (laziness on my part, and tunability. The generator could have been a logic gate or any crystal clock circuit really, although the programmable chip provided fudge room which I didn’t [and hopefully won’t] need) and drives it through a resistor to whatever gnarly sensor plate you have, and then filters and rectifies what’s left. They use hand capacitance to form a variable RC filter; the output of this device is a voltage which is inversely proportional to the capacitance at the sensing node. Not perfect, but pretty good. These sensors also use 1/8″ cables to carry power, ground, and signal, cause 1/8″ cables are cheap and promised to make wiring the beast a lot easier.

The thermometer. Some SMT LEDs on a stick. Yaaaawn.

All this stuff got packed up to schelp to Chicago.

“Video Game TiVo” Revised for Production

Monday, January 4th, 2010

So over the last couple years I’ve been building different variations on this thing for my client/buddy Cory. It’s had many names but the one we tended to call it the most often was the “Video Game TiVo”. It’s basically an AVR with a ton of Atmel Dataflash as well as some Vregs, level translators, and RS-232 chips.

The idea with these guys is that they sit around on a video game controller and log what the user is doing, and then spit that biz back out when you tell them to. The original ones simply hung out watching or asserting the actual switch lines using WPUs and the like, and as time went by they began to actually replace the controller interface entirely and deal exclusively with serial. Depending on the game system, they can sometimes play a game back deterministically, but mostly not because of RNG and/or timing issues. Either way, they’ll record MONTHS of game and can loop arbitrarily, etc etc. They also have a fancy terminal built in for communicating with a PC and recognizing different video game consoles.

Cory wanted them so he could throw infinite gutterballs in Playstation Bowling games. They do that just fine :-)

This one was tested on a PS1 and the canonical bowling.
This January I had geared up to finally make a TON of them so Cory could just have them handy and not need to call me when he needed one, and this was the final test run before we went into production.