Fragments of SquiggleCon: Sex and Probability

A short while ago, someone on Quora asked the question, What is the kinkiest sex toy you have ever used? It’s a tricky question, but not for the reasons you might think. And I’m afraid the answer involves math.

And prime numbers. Hang on, I’ll get to that.

I own three violet wands. I sometimes use one of them with a body contract probe while I hold a giant Medieval battle axe. Touching someone with the axe causes all these lovely blue sparks to jump from the axe to the person I’m touching. There are folks who think that’s kinky, and folks who are like “Violet wand? Ho hum.”

I have a set of poi-handled floggers. I can spin them the same way I spin fire, flogging the holy hell out of a partner while looking stylish doing it. I recently did so to my wife in front of a small audience. But at the end of the day, no matter how flashy your technique, floggers are still floggers—they’re pretty much entry-level kink toys.

I have a straitjacket I’m quite fond of. I’ve been placed in that straitjacket by my partner Zaiah while she pegs me with a custom-modified strapon.

I have a sound. I got it on my wedding trip; it was used on me by my wife and my girlfriend at one of the wedding orgies. Actually, I now have two sounds, one of which I got recently in Boston—that will be the subject of a future episode of this series. (It involves churches and my crush. It’s a good story.)

The sound almost got me in trouble, in fact. I was flying back from the wedding when the TSA agent ran my carry-on bag through the security X-ray multiple times, then finally tore it apart and found the sound, which was tucked (naturally) in my toiletries kit.

“What’s this?” he asked. “Is this a weapon?”

“No, it’s a sex toy,” I said, and explained how it was used. He tucked it hurriedly back in my bag and waved me on my way.

But I digress.

Even a lot of hardcore kinksters wince and cover their nethers at the notion of sounding, but that doesn’t necessarily make a sound a kinky toy; the first time Maxine ever sounded me, she used a smooth aluminum chopstick. Are chopsticks kinky?

That’s the problem with asking “what’s the kinkiest sex toy you’ve ever used?” Kink is in the person using it, not in the thing itself.


So let’s talk kink. And math. And probability. And prime numbers.

Right now, the kinkiest thing in my repertoire is probably this:

It’s a six-sided die, unremarkable except that it’s made of aluminum rather than plastic, because metal dice are cool.

Before I headed out to Europe for SquiggleCon, my wife, my partners, and my crush started a private Facebook group to discuss what to do with me. Or, more accurately, to me.

It was generally agreed that if I was to be in Europe at an extended orgiastic gathering in rural England, I should be in the proper…err, frame of mind for the event.

So the women in my life schemed and plotted, and hatched a Plan.

For the six weeks prior to flying to Europe, I would, each day, roll one six sided die. The day’s roll would be multiplied by the previous day’s roll, producing a number between one and thirty-six. That number would be the number of times I would edge myself that day.

Orgasm, however, was strictly forbidden.

For six weeks.

This had, as you might well imagine, Gentle Reader, the effect of focusing my mind to a laser-like sharpness, oh yes it did. You don’t know what “horny” is until you’ve spent six weeks in mandatory compulsory edging without gratification.

The idea was to do far more than keep me horny, though of course having one be horny at an orgy has benefits self-evident to the most casual of observers.

No, they wanted me horny and malleable. It was hoped that the lengthy period of frustration might put me in a psychological state where I was more suggestible and more given over to doing whatever I was told.

When I was lying in bed one night after a particularly long session of self-non-gratification, my mind went, as it often does, to mathematics. I tried to figure out what the probability distribution for multiplied dice rolls was.

This is not easy to figure out.

If you add dice rolls, you get a perfect Gaussian distribution, as any player of pen and paper role-playing games well knows. The distribution of two six-sided dice added together looks just like you’d expect it to.

Look at that symmetry! Look at that perfectly even distribution! You know what you’re getting, when you roll 2d6.

But what happens if you multiply the numbers instead of adding them?

Well, then the situation goes all cattywumpus. There is no beautiful symmetry, no lovely, lovely Gaussian distribution. The probability graph is disconnected and helter-skelter.

One thing you might immediately recognize is that when you multiply the results of two six-sided dice together, you can never get a result that’s a prime number greater than 5.

What’s less intuitively obvious, until you think about it just a bit more, is you can also never get a number that has a prime factor greater than 5. 14, for example, is right out.

The probability graph looks like this:

Just…just look at that abomination!The most probable numbers are 6 and 12, with about an 11% chance of either. There’s a great void between 25 and 30, and another between 30 and 36. You can get a 1….and it’s exactly as probable as getting a 9.

It’s very untidy.

It’s a bit more useful to look at the probabilities as a matrix rather than a graph. When you do, you see that this matrix has interesting properties along every row, column, and diagonal.

This mathematical construct shaped my experience every day for more than six weeks. This seething, chaotic mess had me a seething, chaotic mess by the time I arrived in Europe. With the poi-handled floggers and the sound and the other kinky toys I own (lesson learned, by the way: put your sounds in checked luggage!).

Kink is always in the people. Using dice to change someone’s psychological state so as to make them more obedient and open to suggestion? I’d say that’s…relatively kinky.

The sound did end up getting used (several times, once while I was wearing the straitjacket), but is that the kinkiest toy I’ve used?

For right now, I’m going to go with no, the kinkiest toy I’ve used is…the humble six-sided die.

Sex toy review: Lovense Hush

I met her at a castle in France. Twenty-two people or so all came together to celebrate the birthday of my partner Maxine in the best way kinky poly people know how: by spending a week having kinky group sex in a castle.

I found myself with a bit of a crush on her almost immediately. We had a lovely time snogging.

I talked about that crush in an answer on Quora, in fact.

Fast forward about eight years. I invited her to my wedding. We’re all sitting there at dinner: me, my wife-to-be, Maxine (who graciously agreed to be the best man at the wedding), my other partners, the bridal party, mutual friends, when Maxine says “Hey Eunice, did you know Franklin has a crush on you? Check out what he wrote about you on Quora!”

Because that’s just the kind of troublemaker Maxine is.


Maxine, me, Eunice, arranged in order of height but not in order of evil

Now, Eunice lives in London, and I do not. She also doesn’t do long-distance relationships. So we’re in a…well, let’s just call our situation a “situationship” and leave it at that.

A long-distance situationship requires a fair bit of creativity, to overcome the logistical incompatibility inherent of being a very small creature living on a very large world.

Fortunately, we live in an era of technology. And the last half-decade has seen a renaissance in high-tech sex toys.

Ladies and gentlemen, I present the culmination of thousands of years of relentless technological progress, stretching in an unbroken line from the first stone tools to the Information Age: the Lovense Hush.


So much better than flint knapping!

When you buy a sex toy that comes with a 40-page instruction booklet, you know you’re in for a treat. (Granted part of the reason it’s that long is it’s written in several languages, but still.)

Remote-controlled sex toys are the greatest gift to long-distance relationships since the invention of writing.

They’re not everything, of course. Part of the creativity we’ve had to exercise as part of this situationship has involved installing new server infrastructure in the house and brushing up on open-source streaming video server software. I now have a streaming camera in the bedroom that any of my partners can log in to so as to make sure I’m properly behaving myself, which, given the sorts of folks I like to date, generally means behaving very improperly indeed.

It was nice to find a turnkey gadget that allowed her to reach out and touch me without the need for fussing with Darwin Streaming Server or dynamic DNS configuration. The current state of the art in open source software is why we can’t have nice things…but I digress.

This is a lovely device. It’s absolutely fantastic fun. The smartphone software is easy to use, though you need to register an account with Lovense to make use of it…such is the nature of our modern, interconnected world. (And, as we recently discovered, it won’t work long distance if the vendor’s authentication servers are down. This, too, is the nature of our modern, interconnected world.)

While the Amazon description doesn’t mention this, the control app included an alarm clock function.

Let me say that again to let the magnificence sink in: The app includes an alarm clock function! I anticipate that making waking up in the morning a whole lot more interesting.

The plug itself is quite well-designed and definitely stays put even when you’re out and about. It’s not silent, but it’s a lot quieter than many other wearable toys I’ve used. In a normal environment like a restaurant, the sound it makes is not likely to be noticeable.

It offers powerful vibrations, of a deep, raspy sort. I quite prefer this to the high buzzing of some other vibrating toys.

From an engineering perspective, it’s covered in silicone, but it is not solid silicone all the way through; the electronic gubbins are inside a hard plastic shell beneath the silicone. For that reason, it’s a lot harder than pure silicone plugs. I was debating whether to get the small or large size. I’m glad I went with the small. (If you’re contemplating getting one of these but on the fence as to size, I’d recommend going with the smaller size, simply because if you’re accustomed to other toys the hardness of this one makes it feel a bit bigger than it is.)

The description advertises 1.5 to 2 hours of use. We get 2 or more, but that might be because my crush is a tease and likes to run it at low levels just to frustrate me. If it’s not running at all, expect about a full day of standby power on one battery charge, which means if you’re in, say, hypothetically speaking, just as a random example, the Pacific time zone, and your significant other is in London, and you wear it to bed, you might expect to be jolted out of your sleep at 4AM when your London partner is waking up for the morning. Just, you know, hypothetically speaking.

All in all, this thing is quite lovely. Definitely worth the price. We’ve talked about getting one for her.

Moving into the Modern Era

I first released my sex game Onyx twenty years ago. I’ve been maintaining it and distributing it from various Web sites ever since, and to be honest, the Web sites I’ve been distributing it from haven’t advanced a whole lot in that twenty years. Seriously, if you want to see the Web as it was in the 90s, look no further than my Symtoys site. (Mobile browser compatible? Pah! What’s that? In my day, we surfed the Web on dial-up from a Mac IIvx!)

As I work on making Onyx 4 more accessible and modern, I’m also working to dust off my own corners of the Web. And I’ve just completed a big part of that.

I am pleased to announce a brand-new, modern Web site for Onyx. And I’ve also dragged my boots out of the mid-90s and upgraded to a completely new Web shopping cart for all my posters and stuff.

And you can help me celebrate!

Special offer! Use coupon code

newsite17

on checkout for $6 off registration!

Download Onyx here!

Update 9 on the Bionic Dildo: Lots of progress!

A few folks have been wondering where we’re at on the Bionic Dildo, as we’ve taken to calling it.

We’ve made a lot of progress in the last few months, starting with setting up a workspace for research, development, and testing. We’ve moved into the new space, where we have a lot of resources we didn’t have before.

The first few prototypes were put together by modifying existing sex toys. This crude approach was good enough to show us that the basic technology is sound, but the prototypes we built this way were limited, fragile, and rather uncomfortable to wear.

Since then, we’ve acquired a 3D printer and facilities for making ceramic molds to cast silicone. This allows us to create custom-designed silicone with electronics, sensors, and electrodes cast right in.

From 3D rendering to printed positive that we use to make a mold.
And yes, those are Lego bricks we’re using as a mold box!

We’ve 3D printed and made silicone test casts of the insertable part of the device. Here’s a test cast of the insertable with electrodes directly embedded in the cast, a huge improvement over our first few prototypes:

Right now, we’re moving into a development phase aimed at answering questions like:

  • How many sensors and electrodes do we need?
  • What’s the neural density of the inside wall of the vagina?
  • How much variability is there in sensitivity between different people, and between different parts of the inner anatomy of the same person?
  • What’s the best way to modulate the signal in response to pressure on the sensors?
  • What’s the maximum perceptual spatial resolution of the inner anatomy?

The first-generation prototype had three sensors and three electrodes, and the insertable part was rigid plastic, which as you can imagine was not terribly comfortable and certainly not workable for long-term use. The prototype we’re working on now is an enormous improvement: fifteen sensors and fifteen electrodes, embedded in custom silicone that’s far more comfortable.

We’re excited with the progress that we’ve made, and looking forward to what we can learn in 2017.

Want to keep up with developments? Here’s a handy list of blog posts about it:
First post
Update 1
Update 2
Update 3
Update 4
Update 5
Update 6
Update 7
Update 8
Update 9

A lot has changed in twenty years

Wow, has it really been twenty years? My God.

Back in 1996, I released the first version of the sex game Onyx. It’s a game for two to six adult players, played a bit like Monopoly (the players can buy properties on a game board) but with a twist. Each player fills out a profile specifying sex, orientation, and kinks, and if a player lands on a property owned by someone of the correct sex and orientation, the player can pay rent or work off the debt. Working off the debt causes the game to search its database of sex acts and draw an appropriate act that fits the genders and kinks of the players.

All very straightforward, right?

Fast forward twenty years. I’m working on (among many, many other things) an update to Onyx, Onyx version 4, and I’m a lot more aware now than I was then.

Twenty years ago, I thought there were only two possible sexes, and the idea that someone might be trans wasn’t even on my radar. (And nonbinary genders? Way outside my conception!) One of the things this new update includes is a complete overhaul of my assumptions, which means a complete overhaul of some legacy code that stretches clear back to version 1.0.

Onyx 4 will allow players to specify their own pronouns however they like, and will be much more accommodating of trans and nonbinary players. As part of the update, I’m going through the database of sex acts, and man, I made a lot of assumptions.

Assumptions about pronouns. Assumptions about genitalia. Assumptions about what would and would not be possible when someone identified as a particular gender.

It’s slow going. There are hundreds of actions in the database, and I’m having to go through and check every one: am I using hard-coded pronouns? Am I presuming what the players’ bodies look like? (Spoiler: Yes. Yes, I was.)

It’s been an interesting exercise, being confronted with these assumptions in a direct and systematic way. I hope the new version, whenever it’s done, will be more accessible and accommodating for more people.

Call to the Interwebs: Looking for experts!

Most of the folks reading my blog are probably familiar with the high tech sex toy my partner Eve and I are working on. Essentially, we’re making a strap-on covered with sensors, that uses direct neural stimulation to allow the wearer to feel touch and pressure on the strap-on.

We’ve built several prototypes that validate the basic idea, and we’re excited to move into the next phase of development.

To that end, we need your help! We’re looking for two things:

1. A person skilled with molding silicone who is willing to work with us to do one-off and two-off custom castings that integrate sensors, electrodes, and electronics into the casting.

This person will know a great deal about custom-molding silicone and be willing to work with us with some fairly exotic requirements, like molding silicone with electrodes embedded in the surface.

2. A skilled electronics person with knowledge of RF analog electronics. I know digital electronics, and so far, the prototypes we’ve built have used electronics and firmware I’ve written. But I’m a bit rubbish with the electronics stuff. Specifically, what we need is someone who can design circuitry that can be controlled by an embedded microcontroller and can modulate the amplitude of an analog signal based on input from pressure sensors. Imagine a signal generator that produces a signal something like this:

What we’re looking for is someone who can design a circuit that will modulate the amplitude of this signal in proportion to the input from pressure sensors…but, naturally, the human body being what it is, the correspondence is logarithmic, not linear (hence a programmable microcontroller doing the work fo figuring out how strong the signal needs to be).

We do have a budget for accomplishing these tasks. It’s not a huge budget, mind you; we’re a small startup, and that’s how it goes with small startups.

If you are interested or know anyone who might be, please let me know! You can reach me at franklin (at) tacitpleasures (dot) com.

Want to keep up with developments? Here’s a handy list of blog posts about it:
First post
Update 1
Update 2
Update 3
Update 4
Update 5
Update 6
Update 7
Update 8

It’s the summer “Help Franklin Pay His Taxes” sale!

It’s that time of year again, when Franklin realizes that the tax bill is coming due and it’s going to be down to the wire about whether he can pay it.

But my distress is your gain. I’ve just created a new coupon code for registered versions of my sex game Onyx.

What is Onyx? Glad you asked!

Onyx is a sex game for 2-6 players. Think Monopoly, with a sexy twist. If you land on a property owned by another player, you have a choice of paying rent or working off the debt. If you choose to work off the debt, Onyx looks at its vast database of sexy fun things to do to show your gratitude for being allowed to stay on the other player’s property.

You can download it free for Mac, Windows, and Linux. And if you want to register the game, use coupon code Summer16 to take $6.00 off the full version.

[ Download Onyx here! ]

Unwrapping a new project: an uncensored Amazon erotica search tool!

I am a self-published erotica writer. I write BDSM fiction, including the novel Nineteen Weeks, a story I’m very proud of.

A couple of years ago, I discovered that the number of books I was selling suddenly fell off a cliff. I did some research and found that the same thing was happening to a lot of erotica writers, especially self-published writers. Amazon’s Search function on their Web site was filtering out a lot of erotica, particularly erotica with themes of non-traditional relationships like BDSM.

However, I discovered something interesting a few months back: The Amazon search API, a set of programmer’s tools that allows Web programmers to search Amazon’s book titles, doesn’t filter search results. You can log on to Amazon and do a search for a particular book and see no results, but if you write a Web site that uses Amazon’s API and do a search, ta-da, there it is!

I’m sure you can see where this is going.

On and off for the past few months, I have been working on building a new Web site, called Red Lit Search. This site has a database of erotic books in Amazon’s catalog–so far only about eighteen hundred or so, but the list is growing–and also allows you to do uncensored searches of Amazon. My hope is to grow it into a portal for erotic books; if it succeeds, I plan to add new sections with things like articles, interviews with erotica writers, and all kinds of fun stuff like that.

So check it out! Spread the word! Kick the tires, test the software, and let me know what you think!

[ Visit Red Lit Search, the erotica search engine ]

“I trust my girlfriend. I just don’t trust other guys.”

It’s a comment I see scattered far and wide across the Internetverse. In almost any conversation where some guy is complaining about his wife or girlfriend having male friends, inevitably someone else will ask, “don’t you trust her?” And inevitably, as sure as night follows day, he will say “Oh, I trust her, I just don’t trust other guys.”

Which, as near as I can tell, translates into English as “I don’t trust my girlfriend.” Because the only alternative reading I can see is far more horrifying.

First things first. Let’s call this what it is: an endorsement of the belief that what women want doesn’t matter.

“I trust my girlfriend.” I think my girlfriend wants to be faithful to me, wants to support me, wants to be with me. “I just don’t trust other guys.” Because at the end of the day, it doesn’t matter what she wants. She’s not a man. It only matters what those other guys want.

There are a couple of ways to read this, one of them pretty messed up, the other one even more so.

The first, messed-up reading: My girlfriend wants to be with me and be faithful to me, but other guys don’t want her to be. Other guys will trick, persuade, cajole, or convince her to cheat on me. You know, because they’re guys and she’s a woman. Women are weak of will, incapable of holding out when faced with a determined guy who wants to seduce her.

The second, even more messed-up reading: My girlfriend wants to be with me and be faithful to me, but other guys don’t want her to be. They’ll just rape her. Because, you know, they’re guys, and that’s what guys do.

Regardless of the reading, the conclusion remains the same: Ergo, the thing I must do is prevent my woman from hanging out with other guys. Charmers or rapists, it doesn’t make any difference if she wants to be faithful to me; they want her, so they’re going to fuck her.

And that’s a whole world of messed up right there, it is.

Disempowering and infantilizing on the one hand, or implicitly supportive of rape culture on the other—there’s no interpretation that makes this idea smell any less bad.

So, I would like to have a word with all you men out there who have ever used this reasoning, thought about using this reasoning, or nodded in sympathetic agreement when someone else has this reasoning. I will try to put this as delicately as possible:

Cut it out. It’s bullshit.

“I trust you, but…” is just a way of saying “I don’t trust you.”

Look, I get it. It’s scary to trust someone else. When you do, you’re putting your heart in their hands and giving them a chance to let it shatter on the floor. You’re hoping they won’t drop it, knowing it will hurt if they do. I totally understand how scary that is.

But you can’t have it both ways.

If you trust your partner not to betray you, you have to have confidence that she won’t even if she has the opportunity to. And if you try to control her to prevent her from having the opportunity to hurt you, you don’t trust her.

This is not about other guys or what they want. It’s about her.

If you don’t think she can say “no” to a silver-tongued bloke with a huge, massive, throbbing bank account, you don’t trust her. If you trust her, it doesn’t matter what other men’s intentions are.

And if you assume as a given that other men who take an interest in your girlfriend will ignore her ‘no’ and just rape her, there’s a bigger problem than her fidelity. Perhaps it’s time to stand up, you know? And I don’t mean stand up to control your girlfriend. I mean stand up against the notion that it is in any way, shape, or form acceptable to assume that other men will not listen to her ‘no’ and there’s anything normal about that…because there isn’t.

“I trust my girlfriend. I just don’t trust other guys.” Basically, you’re saying your girlfriend’s desires don’t matter.

Is that really what you believe?

My hunch is that it’s not. My hunch is what you’re really saying is you think your girlfriend will choose to cheat, but you don’t want to say it because you understand what it might mean. You don’t trust her, and a healthy relationship can’t function without trust.

If you trust her, it doesn’t matter what other guys want. If you don’t trust her, have the courage to own it. But listen, all you other men out there, enough with the “I trust her, I don’t trust other guys” already.

You aren’t fooling anyone.

Sex tech: Wave your arms in the air like you just don’t care

The street finds its own uses for things.
—William Gibson, Burning Chrome

Imagine, if you will, a device you strap onto your lower arm. This device has a bunch of embedded myoelectric sensors that respond to hand movements, and accelerometers that track arm movements. Yoked to these is a Bluetooth transmitter that relays a stream of data about your hand position and arm motion to a computer or smartphone. Sound exciting?

Meet the Myo, a gadget in search of a purpose.

It’s a neat, if pricey, device still in search of a killer app. It comes with a PowerPoint plugin that lets you flip through slides by waving your arm in the air. There’s an interface for Skyrim, though it’s a bit laggy and you can’t play for long before your arm gets tired. There’s also a bit of software that lets you control a small drone with arm gestures, though with less precision than a conventional remote control. It’s very much a “build first, look for a function later” gadget, reminiscent of many tech innovations from the age of the dot-com bubble.

In most industries, the “build it and they will come” approach to project engineering is looked at with less and less favor these days. I am a long-time mad scientist with a particular flair for designing and building all manner of high-tech sex toys, though, so to me “build it and they will come” is what gets me out of bed in the morning.

As soon as I saw a demo of the Myo, my mind instantly went to sex. Controlling a device remotely by gesture and motion? What could possibly be more fitting in a sex toy? (In fairness, I did once, many years ago, build an Internet-controlled sex toy called the Symphony—a name that might perhaps be more appropriate for a device that you can operate by waving your arms. Dance, my puppets! Dance!)

So imagine my surprise when I Tweeted that this would make a cool controller for a sex toy and shortly thereafter one showed up on my doorstep, courtesy of AV Flox over at Slantist.

Electronically, the Myo is a Bluetooth LE radio, a set of myoelectric sensors, a suite of accelerometers, and a low-power processor core running proprietary firmware. Information from the myoelectric sensors is interpreted and translated into a set of posture information. This information is combined with data from the accelerometer and transmitted as a series of gestures and motions.

Conceptually, it looks a bit like this:

The Myo communicates with a laptop or smartphone. The laptop or smartphone interprets the messages from the Myo, then sends appropriate commands to an Arduino with a Bluetooth board connected, instructing it to to run (or stop) a vibrator attached to the motor driver.

The Arduino is a small single-board computer that was designed to do easy experimenting with programmable devices. Think of something like a Raspberry Pi, only far simpler and without an operating system. You can get many additional boards for the Arduino to do all sorts of things—Bluetooth, WiFi, networking, sensors, motor drivers, and other boards exist. The Arduino and its add-on boards are designed to be stacked on top of one another, to make project development easy.

The laptop or smartphone is necessary because of Bluetooth’s design. Bluetooth is a computer-to-peripheral technology. A Bluetooth network uses a master/slave topology, which means a Bluetooth peripheral can’t communicate directly with another Bluetooth peripheral—a “master” device like a laptop or smartphone is needed as an intermediary. When I first started working on a Myo-controlled sex toy, I did the development on a Macbook Pro laptop.

The Hardware

For the first-generation version of the gesture-controlled sex toy, I opted to use an Arduino Uno with a Red Bear Bluetooth shield and one of Kyle Machulis’ Pen15 vibrator controller boards, largely by virtue of the fact that I already happened to have all of them sitting on my workbench.

The Arduino is a small electronics board, roughly the size of an index card, that’s easy to program and capable of talking to all sorts of peripheral hardware. As a controller for a sex toy, it’s a bit large and clunky. Combined with a Bluetooth board and a motor control board, the whole ensemble is about as big as a pack of cigarettes; not exactly discreet. There are several much smaller development boards available, and a later version of this project will probably be about the size of a quarter.

The Arduino, Bluetooth board, and motor controller, all stacked atop one another, look like this:

The blue board on the bottom is the Arduino itself, and contains the processor, power supply, and USB interface for programming. The red board in the middle is the Bluetooth board. The green board on top is the Pen15, an interface board designed specifically to run a sex toy from an Arduino. All together, this stack of boards cost about $40 or so.

The Software

Assembling the stack of components to make a Myo-controlled sex toy was the easy part. Writing the software turned out to be a bit more aggravating.

There are two parts to the software: a program running on the laptop (or smartphone, but for convenience I wrote the first version on my laptop), and a program running on the Arduino. The laptop software needed to pair with the Myo and the Arduino’s Bluetooth card, accept incoming data from the Myo, figure out how to translate those data into sex toy functions, and then send appropriate commands to the Arduino. The software on the Arduino needed to accept those commands and run the vibrator accordingly.

The Myo does a lot of on-board processing to figure out what hand gestures are being done, then sends the gesture data to the computer. It can recognize certain gestures, like making a fist, spreading your fingers apart, and tapping your thumb and forefinger together. It also sends information from the accelerometers, to report motion data.

For the first version, I wanted to keep things simple. I decided to look only at hand gestures, rather than arm motion. Making a fist, I decided, would turn the vibrator off; spreading my fingers would turn it on. (I opted not to control the speed of the vibrator, even though this is fairly straightforward for the Arduino to do, just to keep things simple.) This let me ignore accelerometer data and look only at hand gestures.

The Arduino software was relatively straightforward. The Arduino Bluetooth card comes with a programming library, which, much to my dismay, failed to work right out of the box. That’s surprisingly common in the world of Arduino development, where hardware and software is often designed by small groups of dedicated enthusiasts and may or may not work as expected the first time. An hour’s worth of Googling and some trial and error let me get the Arduino Bluetooth library working, and after that, things were a lot easier. I chose a command that would mean “vibrator on” and another that would mean “vibrator off,” and wrote a simple program that would poll the Bluetooth card looking for those commands and send the appropriate signal to the Pen15 board. All in all, the Arduino side of the equation took an evening to get sorted.

The computer/Myo side was a bit more complicated. The Myo I received was one of the first to ship, and the Myo’s software development kit was a mess when it was first released. (It’s still something of a mess now.) I had considerable difficulty pairing with both the Myo and the Arduino—something that wasn’t helped by the fact that Mac development is usually done in a language called Objective-C, and my experience with Objective-C is limited. It’s mostly like C++, mostly, but there are just enough differences to trip up anyone accustomed to C++.

I finally gave up on accessing the Myo directly and opted for a shortcut. The Myo comes with software that maps Myo gestures onto the keyboard, so I decided to make things even easier by going that route. I mapped an open-hand gesture to the letter ‘a’ on the keyboard and a fist to the letter ‘z,’ and decided to write the software so that it would send a “vibrator on” signal when it saw the letter ‘a’ and send a “vibrator off” signal when it saw the letter ‘z.’ I figured once I had that working, I could get more fancy and sort out accessing the Myo directly later.

It took a good bit of time to get even that part working. The software development kit for the Arduino Bluetooth card is, if anything, in an even more sorry state than the Myo SDK. It took a lot of hair-pulling to get the sample code to work properly, and it tended to break whenever I tried to modify it.

In the end, I did finally get it to work, after a fashion. It was (and still is) quite crude: it recognizes only two Myo gestures, which it translates into “run the vibrator at full speed” and “turn the vibrator off.” The software still has a maddening habit of losing touch with the Arduino occasionally, for no reason I can discern, but it works.

The test

I decided to try out the vibrator with one of my girlfriends who was visiting from the UK, where she lives. We had just finished a whirlwind three-week camping tour of ghost towns through the Pacific Northwest, a journey I am still chronicling.

We spent her last night in Portland at a hotel near the airport, and I thought, hey, this would be an awesome time to take the new toy for a spin, and maybe even get some video of the device in action. She thought that idea sounded splendid.

Unfortunately, the software had other ideas. As often happens, somewhere between being tested on my workbench and being tried in the real world, it decided to quit working. I debugged frantically while she lay naked in bed waiting. Eventually, she fell asleep, and the opportunity was lost.

Later testing would have to wait for a more favorable time. Eventually I was able to get it working again, but the moment to use it with her had passed.

The future

The current prototype gesture-controlled sex toy is quite primitive. Put together, it looks like this:

The hardware is still clunky. I plan to rebuild it using a DF Robot Bluno, which combines the Arduino and Bluetooth on a tiny board roughly the size of a quarter.

This should make it possible to create a discreet, miniaturized sex toy that can be worn in public. I have one of these sitting on my workbench, but haven’t had a chance to play with it.

Eventually, when I’ve made more progress on the strapon the wearer can feel and I have time to return to this project, I plan to refine the software, adding accelerometer control and allowing the vibrator to be controlled more precisely—perhaps by adding patterns to the vibration. (I have visions of doing a PowerPoint presentation at a business function while one of my partners sits in the audience wearing this device, as it responds to the same gestures I’m using to control the PowerPoint slides.)

Finally, I want to compile the control software for my iPhone, so I don’t have to lug around a laptop wherever I might want to use it. I can keep the iPhone in my pocket, where it silently listens to the Myo and sends signals to the sex toy.

The possibilities of remotely operated, Bluetooth-controlled sex toys that respond to wireless sensors, controllers, and other devices has a great deal of potential, especially if you’re a mad engineer like me. There’s rich territory here, just begging to be explored by intrepid adventurers. The early Myo prototypes are, I think, merely the tip of the proverbial iceberg. I can hardly wait to see what else is possible!