Text message control of your electro box

Although this page was written with reference to the E-Stim systems 2B electro box, it's applicable to any box that has an audio input. All you need is a spare old mobile phone, and you too can control the electro box remotely, via text message.

Obviously, text messages aren't ideal for everyone, and in some situations you'll want more direct control of the box, either over the internet or from a computer connected directly to it. I've got that covered too.

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The basics

As I said, I did this with my E-Stim Systems 2B controller, but it would work with the Series 2, and indeed with any box that has an audio input. Plug the phone's headphone output into the E-Stim audio input, and you're away.

Essentially, a piece of software on the mobile phone listens for commands in text messages. When it sees one, it then plays one of three different audio files stored on the phone - these are tracks taken from the CD that accompanies that 2B, but could be anything that works well for you. The box is set in audio mode, and so is triggered when the music is played.

At the moment, I have three trigger words set up - 'short' 'medium' and 'long'; the first corresponds to an audio track of about 18 seconds, the second around two minutes and the long track is about five minutes.

A cheap PAYG SIM is in the phone - which is my old Nokia N95, but any phone with Symbian will work - and when it receives a text message, it checks for the appopriate word; if found, it replies with the same word, so the controller has confirmation their message got through, then it starts playing the associated audio file. When the playback has finished, it sends the message "complete" and waits for another text message.

It's possible to send a series of messages, and the program will loop through them all one by one, so there wouldn't be much gap between playbacks.

But what's it for?

Well, though not as compact as a dedicated remote-control e-Stim system, this also isn't limited by distance. If you could fit the phone and the estim unit in a backpack or pocket of some combats, you could use it in a club, allowing the controller to stimulate (or perhaps summon) the person wearing the unit. Or, as I've done before, if you're waiting for someone to arrive for a scene, you can get yourself ready, and they can send text messages along the way to warm you up, as it were.

Pros and cons

There are drawbacks to this, of course, as well as advantages. On the plus side, it means you don't need continuous connection to a network - as long as there's phone coverage you can do this. So it will work more or less anywhere.

The main drawback is that, beyond selecting which audio file is played, and when, the controller doesn't have any more control - the person with the box could turn the levels right down, for example, which might rather defeat the point. But, if you trust them not to, then you can have a lot of fun with this.

How it works and what you need

First, get your stim unit, and experiment with the audio files that you like. Pick three of them of different lengths, or intensities, or whatever you like. I say three, because that's a handy number - you could change the software to have as many as you like.

Then, find a mobile phone. I'm using an old Nokia N95, which runs the Symbian OS. It's what I had lying around, and it's very flexible. My original thought was to simply have two sound files, using one for the ring tone, and one for the test message tone. That won't work satisfactorily, though, since ringing tones and message tones are always played through the speaker, even if you have headphones plugged in, and the volume through the headphone socket isn't as high as it needs to be.

Play the sound through the phone's music player, though, and everything is perfect. So, the task is how to arrange that remotely.

The answer I've come up with is a programming system for Symbian called M-Shell. This is a scripting language - you install it on your phone, then write scripts to control the phone's behaviour. My script is called AudioRemote, and it's pretty simple; I'm more than willing to share the code if anyone wants.

It loops through text messages, behaving as I described above, and looking playing audio files that are stored in the estim folder on the phone's memory card.

There are some things to beware of - you should edit the phone settings substantially, for best effect - turn keypad tones, warning tones, ring tones and sms tones off. Although they won't all be very loud, they will cause unexpected audio, and you don't want that. Who wants a shock in their balls just because some parasite's trying to convince you to claim for an accident you didn't have, after all?

Here's a picture showing the phone running the software, wrapped up in wires on top of the 2B controller:

Audio Remote on Nokia N95

Nokia? How old fashioned..

Yep, probably is a bit quaint of me to be using a Nokia phone; it's what I had lying around, so it didn't cost me anything. I might even be able to use the networking capabilities of the N95 and M-Shell to drive my EStim Control/Server software, too, which would be very interesting. You can probably pick up some cheap Symbian phones on eBay if you hunt around.

If you're using Android, it's probably possible to do something very similar using a scripting system developed by Microsoft, called On{X}. I've only had a quick glance at the documentation so far, but I reckon you could recreate something like this very easily. As ever, for more info, nigel at roughsex.org

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