The Bar Code Interpreter is an interface which consists of software and hardware. The software runs under Linux and is written in C. The hardware consists of a bar code scanner, a PC, a custom built interface and a relay switch box.
The software supports any bar code scanning system, which transmits the code directly to the computer system. By means of recognition and interpretation, both software and hardware allow other (electrical) devices to respond directly to any arbitrary (non-manipulated) scanned bar codes.
The idea for The Bar Code Interpreter originated from Lauran Schijvens in the year 2000, as a means of using any bar code to generate unexpected mechanical product identification, rather than for economic purposes or database management. The software and custom built interface were developed by Stock at the V2_Lab in Rotterdam. The relay switch box was originally built by Lauran Schijvens and Jacco Schot in 2001. It was a wooden box with 40 electrical sockets. Naturally, any kind of electrical device can be attached to the switch box.
In 2001 The Bar Code Interpreter was presented by Droog Design in the show 010101, Art in Technological Times at the San Francisco Museum of Modern Art. Due to US fire regulations, the original wooden switch box housing was replaced by a metal housing, by the technical staff of the Museum. The installation piece at SFMoMA was designed by Thonic and Ed van Hinte. The Bar Code Interpreter functioned continuously at SFMoMA for 4 months, interacting with more than 2000 visitors a day. Each time a bar code was scanned, the software and interface supplied 4 different pulses to the switch box, allowing an unexpected set of 4 out of the 40 attached electrical devices to respond directly (this out of 10.000 possible different combinations). Each time the same bar code is scanned, the same reaction occurs. Visitors of the show frequently used their drivers license or ID cards to interact, which meant that the interpreter gave a unique response to their unique bar codes.
Bar Code Interpreter by Lauran Schijvens (2001) from V2_ on Vimeo.
The installation is basically a chain of five links, from input-end to output end;
- Input : A barcode-scanner scans a barcode, converts it to a string of numbers and sends it out the Serial port.
- Process / Decision : A Laptop, hidden from view, receives the numbers from the barcode-scanner, picks four numbers from the string, and decides which outputs to engage, each digit is used to switch one output in a subset of 10. The corresponding outputs are switched with commands sent out the parallel port.
- Interface: This Custom-built box receives commands from the laptop's parallel port, and switches its outputs accordingly. It has four groups of ten outputs, only one of each group can be on. The output-groups are connected to the switch-panel with four standard DB25 cables.
- Switch Panel: The switch panel is a metal box with 40 European-style 220V wall-sockets, again in 4 groups of 10. Each group has it's own automatic breaker (fuse) and main inlet connector (Blue CEE-con standard 220V connector). Inside the box are 40 relays, switched at 24V DC and their 24V power-supply. The outputs of the interface-box are connected to the relays and their power-supply in such a way, that each output of the Interface-box switches one outlet of the switch panel.
- Output: Connected to each outlet of the switch panel is one of 40 household appliances. Any four items from a collection of Hair-dryers, vacuum-cleaner, hand-tools, table-lamps, a slide-projector, a ghetto-blaster, fans, etc. will be switched on for three seconds after a barcode is scanned.