Thursday, February 9, 2012

Fake Prop

Fake Prop during assembly

Sometimes you need to recycle a project to get more fun out of it. This is what happened with the TSS.

This fun project emulates simple exampling parallel functions of a Propeller chip by connecting together a cluster of Basic Stamp processors. Each Stamp represents one Cog, has its own operating program and communicates through a common BUS using PBASIC programming language. Output is to a built-in green screen LCD monitor. Unlike the real Prop, the Fake Prop can be rewired in between its Cogs.

Fake Cog with 8 ports
Fake Prop Schematic

The Fake Prop (FP) has seven BS1 Stamp processors to experiment with Cog emulation, LCD monitor, radio transmitter, radio receiver and a 64K EEPROM memory board, interfaced to a Belkin USB Hub. The FP is larger than a Prop but still small enough to fit into a soup bowl or Parka coat pocket. The yellow wires are for the port-to-port one wire interface. The black wires are adjoining Vss and red wires are Vdd. White represents a serial signal wire. By comparison, the American penny shows size comparison. FP includes an optional serial “green screen” by Parallax.

( ) Plug in seven Stamp computers to the Belkin 7-port hub
( ) Run wire from P0 Computer 1 to P0 Computer 2, repeat to 7
( ) Connect all grounds together with jumper wires (Vss)
( ) Connect all +5 volts together (Vdd)
( ) Consult the schematic to wire the peripherals

Assemble everything directly onto the Belkin HUB. USB Stamps are plugged into all available USB ports. The powered HUB has the ability to draw external power to supply the demand created by seven processors.

Parts List
R1 - 1K Resistor
R2 to R8 - 220 Ohm Resistor
Z1 - Z7 - Piezo Speaker
7 - USB BASIC Stamp

Peripherals Used in this Project, from Parallax
7 – Five Volt Piezo Speakers
1 – Green Screen Serial LCD
1 – 433 Mhz Radio Transmitter
1 – 433 Mhz Radio Receiver
1 – 64K EEPROM Memory Board

New Experiments
The Fake Prop is intended for academics and exampling study, and is primarily just for fun. However, one idea is to create a bunch of external fake props, using any processors which are available, and their native programming languages to create prop emulation software. Then radio transceivers link directly to a project like the Big Brain, which has the ability to receive downlink. This "Fake Brain" can operate alongside the real brain.

How does FP stack up against a real Prop?

FAKE 1.75K   28MHz  64K+     7       7      1   1   1   56
REAL   32K   80MHz  32K      8       0      0   0   0   32

The Fake Prop costs more and is larger/heavier than the real Prop, roughly 2.5 times slower with EEPROM that's 21 times smaller. However, it has twice as much memory,  1.75 times more I/O, and tighter programming code.

FP has some things the real Prop does not have at all like the ability to rewire in between Cogs and access to 3 solderless breadboards for work space, seven speakers, a serial green screen, and full scale long range radio transceiver. For more comparisons, refer to the processor manuals and link. 

Tiny Stamp Supercomputer