The material in this appendix is directly derived from a set of tutorial web pages authored by Andrew Miller. Andrew has since moved on to other pursuits (that pesky "work thing," don'cha know...), so in the interests of education, I "prettied" up his tre
Many BEAMbots are based on bicores (2-Nv neuron "loops") in some fashion or another (and there are two main kinds of bicores -- but more on that later). Even if you're not building a bicore-based BEAMbot, studying how bicores work will help
We assume that the slowly changing waveform at the
Nv
input produces a single output transition when it crosses
the Nv
switching threshold. This is accomplished by using a 74HC14
or similar CMOS Schmitt
trigger. When 74HC04 or 74HC240s are used for Nv
inverters some nasty oscillations occur during switching
which makes these inverters unsuitable for most Nv
networks greater than 2 Nv
in series.
On this page, we'll tackle two challenging topics -- Nv neurons (the building block of advanced BEAM circuits), and Nv nets (networks of Nv Neurons, designed to do our bidding).
The quadcore, or 4-Nv net, is by far the most-common variant of Nv net. You will sometimes also hear this circuit referred to as the "Microcore" -- although this term should strictly be used in reference to a "fully dressed" quadcore,
There are several websites documenting the original Furby circuit board. I decided to replace the original circuit entirely and replace it with a PIC based controller.
Note that the resistor value of the pull-down resistor affects the
voltage at pin 3 of the Furby's connector. We used a 1k ohm resistor
to make it less sensitive to light (since we're now operating with it
open to ambient light).
In the above diagram, a 20k ohm resistor is used as the pull-up
resistor. You can, however, use any resistor as the pull-up resistor
as long as the resistance is high enough to protect the circuit.
Through a lot of hard work by people other than myself, Furby's innner electronics have been fully reverse engineered. To the right is a rendering of the schematic created by Chris Brown. If you've got any corrections, I'm sure he'd be interested.
Three motor designs are much more able walkers with longer strides and very tall steps. They are also a huge jump in construction complexity from a two motor walker. Walker Ver3.0 is controlled by a six-neuron nervous net. I opted not to go with the 4 neu
Behavior Based Artificial Intelligence (BBAI) is a methodology for developing AI based on a modular decomposition of intelligence. It was made famous by Rodney Brooks and his subsumption architecture was one of the earliest attempts to describe a mechanis