Title: What is the Stribe?
Post by: ultrajosh on December 21, 2007, 06:10:27 PM
Stribe 0.2 prototype with colored LEDs
The Stribe is a touch-based music or video controller with no moving parts. It employs 8 touch-sensitive strips flanked by LED bar-graph displays. The controller is user-configurable, connects via standard USB, and is designed to be used with music interface software such as Max/MSP, Reaktor, and others.
The Stribe provides continuous control without delicate, quirky mechanical faders. The LEDs provide a low-resolution display that can provide dynamic feedback on settings, sequencer steps, basically anything you can imagine and then program.
Future add-ons will include MIDI and CV interfaces to allow the Stribe to be used without a computer, as a stand-alone controller.
Right now, you have to write your own programs for the Stribe. There's an evolving firmware that lets you control all the Stribe's basic functions (LEDs and sensors), and matching Max/MSP building-block patches. The contributed example apps so far are already fun to play with, and a great way to learn Max/MSP.
The Stribe is an open project. This means that the circuit designs, firmware, and software building-blocks are all available to tweak and modify for your own use.
There are a LOT of cool ideas floating about what to do with this thing now that it exists. I'm excited to see these ideas come to life over the coming months.
The current design is built entirely with off-the-shelf parts that you can order through most catalogs, except of course the circuit boards. Also, the softpot touchstrips are expensive except in bulk. I plan to have made a custom part, a single sheet with 8 strips which should end up being much less expensive (1 slightly expensive part instead of 8 medium expensive parts). But there will need to be enough interest to justify the tooling and engineering fees.
There is a small prototyping area on the Stribe circuit board to encourage additions and experimentation with the functions the Stribe provides.
8 touch sensors run into 8 ADCs (analog to digital converters) on the uC (microcontroller) stamp, and the uC controls the display via 3 digital pins. The firmware to control the uC is written in C and currently runs on the commercially available Arduino MINI stamp, and also connects to USB through Arduino's USB stamp.
The Stribe display and touch-strip circuits can be addressed by any microcontroller circuit, so you can use Wiring, Freeduino, or roll-your-own. As a standalone fader-bank, (without the uC, firmware, and software) the Stribe interface can still be integrated into your DIY project, if you are building a design from midibox.org (http://midibox.org/) or if you just want a unique alternative to traditional faders. Remember, the Stribe can be a meter bridge, too.
The Stribe driver board provides 3-wire control of 1024 LEDs, and 8 0-5V touch-strip sensors. The current prototype runs on 5V 0.5A provided by the Arduino's USB port. Further testing is required to determine if the stribe will require external power - it seems to take up more than it's fair share from the USB source.
The LED driver circuit uses 16 MAXIM MAX7221 LED drivers to run the 16 8x8 LED grids which make up the Stribe's display. Although I haven't tried it, it should be possible to run multiple Stribe displays from one Arduino, (power requirements for additional displays would need to be accounted-for), since there are more available digital pins. However, additional ADC inputs would need to be multiplexed (or a circuit added to do A/D conversion for the additional sensors... or just use 2 uC's).
For a brief history of the Stribe, go here: http://www.soundwidgets.com/stribe/ (http://www.soundwidgets.com/stribe/)
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