since April 2001

Development History December 2000


At the beginning it seemed impossible to realise such a project from scratch and all during free time. Though as time passed on more and more parts came to work properly.
Now we are close to finish with our SmartBall Project. The balls version 2 are working nearly perfect and we are currently trying to get the PlugInStation running.

Here a chronological look through the development history:

August 1995, EJC Göteborg (S)
At an openstage of the European Juggling Convention (EJC) in Göteborg we've been fascinated by a Globall show with illuminated balls in the dark. Later on that evening we discussed if it would be possible to construct illuminated balls which can change their colour according to a programmable pattern. We imagined how many superb effects would be possible to achieve with such balls. Especially if we could synchronise the colour pattern with a piece of music. As we already performed several times as juggling group Butterfly, we thought a synchronised show with three people would just look crazy with colour changing Globalls.
Back to Switzerland we started to think seriously about such balls, and of course we encountered immediately many difficulties. First we had to find an appropriate material to pour balls. It had to be translucent, not too soft nor too hard and possible to pour at home without large equipment. Silicone rubber seemed to fit that conditions. The next problem was finding a mould. We started with self-made plaster moulds, which had several disadvantages, i.e. a rugged surface. Today we have the possibility to mill moulds with a CNC machine.
In the search of a programmable control unit for our balls we found a such called 'Basic Stamp' (a circuit with a PIC16C54 and an EEPROM which can be programmed in 'Basic'). We've been working for quite a while with this circuit.
Next we had to find bright enough LED's in various colours, which was not easy that time, especially with a low budged. Concerning the financial aspect, we used the money we saved from several performances as juggling group Butterfly.
Some months later we came to the conclusion that this project is too big and too difficult to be finished. Mainly because of a too weak illumination of our very first prototypes.

August 1996, EJC Grenoble (F)
This year the jugglers met in Grenoble. And again we were impressed of another Globall show, this year with balls of different colours.
Back home we revived our project only to fail again.

August 1997, EJC Turin (I)
We had a closer look at the Globalls manufactured by Aerotech (that time not programmable, but available in different colours). We found out that they pour their balls with polyurethan, which certainly fits the conditions better, but needs too expensive equipment to pour, so we decided to stick to silicone rubber for an outer layer around a very hard core.

silicone outer layer / hard core with electronics inside / complete ball

Meanwhile it got easier to buy LED's in red, yellow and blue for a payable price. Only green was still difficult to find.
We designed an electronic circuit ourselves to replace the Basic Stamp. This new control logic with a PIC16C58 processor and a 93LC86 memory fulfilled our demands a lot better.
Because of the obligatory military service in Switzerland and stays abroad we had to stall our work for several months.

August 1998, EJC Edinburgh (GB)
Now we knew that it's going to be possible to create colour changing Globalls. We just needed more time. Additionally we started to develop sensors which can detect the impact of the balls in the hand during catches. With such a feature, many new pattern would be possible. Like a five ball cascade where the balls shine green on top and red in the lower part. Between it should be possible to fade from one to the other colour. Additionally it's possible to store time duration of throughs for later analysis.
We had to check functionality of all parts and optimise it. A lot had to be done. We poured many outer layers out of silicone, we designed electronic circuits, soldered it, checked, programmed, ... We wanted to present our SmartBalls at the next European Juggling Convention.

August 1999, EJC Grenoble (F)
During a very intensive week just before this years festival we built our first set of balls. In the last few days before the festival there was even not enough time for sleep. And we didn't want to miss the total solar eclipse in Germany.
The first set of balls consisted of five balls, a simple PlugInStation and some software to compile and download the programs. All balls suffered from children's decease's. One had some stains on the surface, the next didn't yet understand all program instructions, and so on. The PlugInStation was a wooden board with a box containing a processor, two LED's to signal status and a small keypad where programs could be selected and started.

first PlugInStation with 3 balls version 1

We had to run our software on a very old laptop, black and white display and running with incredible 25MHz. The good thing was we could connect the power supply to the cars battery.
Because of all that small things not running perfect, we decided to show our balls only to few jugglers, mostly friends. The feedback was incredible and all positive. No-one could really believe, that we did all on our own and from scratch.
That summer the people from Aerotech presented their new 'programmable' Globalls. Those balls contain LED's in two different colours and can be 'programmed' with some knocking sequences.
We've been discussing about some kind of co-operation as they are planning to develop PC programmable balls as well. As it would have got too difficult we decided not to.
Anyway we've been working on our balls for our own and not to sell it. We always wanted to have such balls for our own and we enjoyed working on it. So our motivation comes from the work itself and the fascination to design something new and not from marketing thoughts (the marked for juggling equipment is anyway pretty small).
During this week at the festival we had a lot of time to play around with our balls, trying to find all bugs and things we could do better. For example we encountered quickly that our 3 pole stereo plug we used is breaking quickly. After a few days we had to fight against lose contacts which couldn't be repaired. Now we are using self-made plugs, where the part inside the ball (the part which can't be repaired) is 'unbreakable'.
Next, some static discharges caused troubles. We had to juggle with wet hands so that the balls won't stop running. This small bug in the circuit is corrected now as well.
During the year until the next convention we developed and build our second set balls, version 2. We corrected bugs, redesigned our SmartBalls programming language, which consist now of 50 instructions. It is possible to program nearly any pattern.

August 2000, EJC Karlsruhe (D)
Short before the festival we decided to leave our balls at home, as we didn't find time to work on a show. We thought we rather wait another year, then presenting something which is half finished. Even if we risk not to be the first ones juggling programmable juggling balls.
We finished five balls which are working perfect, we are quite happy with those balls. And we prepared most parts for another eleven balls, we only need to pour it.
Currently we are working on the PlugInStation, a big part is already done, though there is a lot of programming still to do. Our compilation software for the computer needs some changes as well.

to be continued ...