Cellular Automaton Shading for Building Envelopes - Cellular Automata in Image Processing and Geometry - page 221

Fig. 11.22 The CASS prototype: 1): Scheme of the logic which emulates 256 ECAs. 2):
Electrical diagram of a CA unit. 3): A photograph of a hardware CA unit. 4): SP with some
LC elements active (opaque). 5): SP following the pattern produced by CU.
prototype of CASS has been documented in [68]. However, since it is based on
ECAs which do not possess good shading properties, it can not be considered as
CASS in the strictest sense. Nonetheless, the original motivation was also: to pro-
vide a physical educational device driven by CA; as an exercise on electric circuitry;
to give students a hands-on experience of CA; to demonstrate the entire process from
designing the circuit logic to fabrication of the CA modules; to teach the emergent
properties of CA [17]. Therefore the logic was designed to allow emulation of all
256 ECAs by setting manually 8 simple switches at each CA module. Interestingly,
this also allows experimentation with non-uniform CA [51], that is automata whose
individual cell rules are not the same. Although the concept of CASS is based on
interactions among autonomous units, the original prototype, for the reasons men-
tioned above, is comprised of two components: the CA control unit (CU) and the
shading panel (SP) based on liquid crystal (LC) technology. That prototype is fully
operational. Since the CA units are based on commonly available integrated cir-
cuits (CMOS), they are much larger than intended for the real application, which
most likely would combine field programmable gate arrays (FPGA) with printed
circuit boards (PCB) [44]. Due to high cost of LC elements, SP is much smaller than