PaulSeward.com

This is Jon Peat, British Young Juggler Of The Year 2006, probably one of the most interesting ball jugglers I’ve seen in a long time.  He was trying out a new routine on stage at the BoB Juggling Festival this weekend. There are some more photos from the show in this album here.

However, the most productive part of the day for me, was my chat to Tarim about my idea for a telephone based siteswap validator.

The Background:
For those that don’t know, siteswap is a mathematical language for describing juggling patterns.  The idea is that you can use a string of numbers to represent the pattern.  Each number represents a throw event, with the number determining how many beats later the object is thrown again. Eg a 3 means that the object being thrown at that time, is next thrown 3 beats later.

Some strings of numbers are valid juggling patterns, for example 531 (which is a 3 object pattern) but not all strings are valid. For example, 540 is not a valid siteswap, as the 5 object is next thrown in 5 beats time, but the 4 is next thrown in 4 beats time. This means that they’re both thrown by the same hand at the same time. There’s a collision.

There’s a lot more to siteswap than that, if you’re interested in all the gory details start here with this wikipeida article about siteswap.

It’s handy some times to be able to check if a string of digits is a valid juggling pattern or not, telephone dials have digits, so they can be used as an input device. They also have earpieces, so can be used as an output device.

The Plan:
To build a device which you can plug an old rotary dial phone into, which allows you to do the following.

1. Pick up handset
2. Listen for a dialing tone
3. Dial in the siteswap you want to validate
4. Hang up handset
5. Wait a few seconds
6. The phone will then ring
7. When you answer the phone, a recorded message plays telling you if the number you dialed is a valid siteswap or not.

I had a firm idea about how to do all those steps apart from step 7, getting a microcontroler to play speech isn’t trivial. Talking to Tarim though gave me an idea of how to get around that though by using a cheap MP3 player.  Result!

I’ve built a circuit which interfaces to the phone line, and can detect hook state and count dial pulses. I can get audio onto the phone line. I know *how* to make the phone ring, but am lacking the components to do so.

In short, I’m *soo* close!

This entry was posted on Saturday, January 30th, 2010 at 11:38 pm and is filed under Experiments, Phones, Photos.
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