Posted in Technology with tags on January 16, 2009 by Simon

Just added a fabmoment describing the Cutout Circuit Boards


Organza touchpad development 2

Posted in Technology, V2_ with tags , , , on January 4, 2009 by Simon

This month I’ve made quite some progress with the transparent touchpad in metallic silk organza. With thanks to Piem who has sewn the thread paths and did the more difficult fabric crafting, I now have a working prototype touchpad.

Organza touchpad

touchpad internals

The prototype touchpad has 8 sensitive areas roughly the size of a man’s hand. All areas are embedded in a single layer of metallic silk organza. Only a light touch of one or more of the sensitive areas is enough to trigger. In total the pad has five layers (might increase to seven depending on the possible addition of a ground ‘plane’).

  • organza sensitive layer
  • two isolation layers (could be one depending on fabric quality)
  • component layer
  • two isolation layer (could be one depending on fabric quality and presence of ground plane)
  • possible ground plane

The sensing boards are constructed out of copper foil circuit boards (cut with a Roland CAMM-1 vinyl cutter at Protospace fablab Utrecht ) and conductive thread. They work by capacitively coupling a relatively high frequency signal put on the metallic organza sense areas. On the left is the A/D converter board (unfortunately TSOP-16 is too small for cutting).

In the movie I overlayed (slightly out of sync) the touchpad output as a bar graph. Only the first 4 (out of 8) outputs are functional in this test (the most left bars in the graph).

Organza touchpad development

Posted in V2_ with tags , , , on December 3, 2008 by Simon


Continued development on the organza soft touchpad.

The basics are working with the CCB’s in place. Much of the electronics (bottom in picture) will be embedded as well in the next generation.

Posted from JoSoS on Flickr: Organza touchpad development

JoSoS changed servers

Posted in Uncategorized on November 26, 2008 by Simon

In a not so long time I will pull the plug out of Mekka our Void7 server. The good old dog is ageing and I do not have the time to maintain any longer.

The consequence is that JoSoS had to move and my choice is to host it at wordpress.com… so here we are.

The old JoSoS can still be found at http://www.void7.org/~simon/josos. This location will be removed somewhere near the end of January so please update your bookmarks, links or whatsoever especially if you are looking for MidiPy or bluespam

Felt Circuit Board

Posted in V2_ with tags , , , on November 26, 2008 by Simon

A CCB (Cutout(tm) circuit board) on a felt carrier.

This is a first try-out of using felt and CCBs. After cutting out the circuit it is stuck on a piece of felt. Hopefully the next version will look a bit more tidy.

The knit thing on the right is a knitted pressure sensor knitted on a knitting machine by colleague Piem. Notice how the LED blinks faster when the pressure increases.

Posted from JoSoS on Flickr: Felt Circuit Board

Prototype organza touchpad

Posted in V2_ with tags , , , on November 26, 2008 by Simon

The first prototype of the Metallic Organza Touchpad I am currently working on. The prototype only has two sensitive areas but this will be increased quite a bunched over time. Also it will be using the CCB (Cutout Circuit Board) as described in the previous post.

Posted from JoSoS on Flickr: Prototype organza touchpad

Prototype organza touchpad

Posted in V2_ with tags , , , on November 26, 2008 by Simon

Since short we have been experimenting with cutting out circuit boards out of copper foil using a vinyl cutter at protospace FabLab. First attempts were with moderate success but fine tuning the cutting settings and adjusting circuit board design the results can be said to be quite OK.

Posted from JoSoS on Flickr: Prototype organza touchpad