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The purpose of a solar engine is to act like a power "savings account" -- a small trickle of incoming energy is saved up until a useable amount is stored

A solar-powered robot can be made to work, even in relatively-low light levels

Solar cell size is minimized

It is powered with two 3.3F Goldcaps. They can be charged in a few seconds. When they are charged, MAXIBUg gets "afraid" of light, and wanders of to go to play "in the dark". After a while, about 20 seconds (depending on the current used by the two motors ), the power has dropped, and it wants to "eat". It gets light attracted, and will turn and go to the light. When it gets there, it will recharge and still will be atrackted to the light until it reaches a trigger voltage , at which it gets "afraid"of the light again. This will go on all day until someone turns off the lightsource. While doing all this it also will backup when bumping into something.

Because of the "on-off" output of the first schmitt trigger, the inputs for the LDRs will switch. That's why it gets light atracted -light afraid. This also means that you cannot use IR diodes (like SHF205). You have to use LDRs !

This adapted photodiode is not as sensitive as large area types so C2 may need to be reduced to 0.01uF while the value of R2 and R3 can be increased by a factor of 10.

Two leaded phototransistors can also be used but may require extra shielding to reduce light current in the bridge to acceptable levels

basic photopopper functions plus reverse -- all on a single chip

A device used to store charge in an electrical circuit. A capacitor functions much like a battery, but charges and discharges much more efficiently

BEAM robots tend to use capacitors in two, very different roles -- small ones in Nv neurons and solar engines (filter capacitors), and bigger ones as energy storage devices (storage capacitors).

The Sharp IR Range Finder works by the process of triangulation. A pulse of light (wavelength range of 850nm +/-70nm) is emitted and then reflected back (or not reflected at all). When the light returns it comes back at an angle that is dependent on the distance of the reflecting object. Triangulation works by detecting this reflected beam angle - by knowing the angle, distance can then be determined.

The IR range finder reciever has a special precision lens that transmits the reflected light onto an enclosed linear CCD array based on the triangulation angle.

The Sharp IR has a non-linear output. This means that as the distance increases linearly (by set increments), the analog output increases/decreases non-linearly.

CALEB CHUNG: Of course we could have used micro-servo motors to accomplish the motion of Pleo, but we aren’t able to use expensive motors. So we had to engineer it with a high-speed motor with high gearing and no backlash for control purposes and have it all fit within the muscle envelope of Pleo.

So what we did was go after a lot of ethology research. How do animals really handle the complexity of their environment? We built a virtual brain—a whole system that decides how Pleo will react in various situations.

CALEB CHUNG: Pleo will reset thresholds and adjust his idea of what he thinks is normal. Let’s say you get Pleo and you take him home to your shag carpet. When Pleo walks, the carpet will drag on his feet. So his force feedback sensors will realize that he is spending too much energy to walk around. Pleo will try different things to reduce the energy spent. Eventually, he will have the idea to step higher. Your Pleo compared to my Pleo will walk with a higher step.

The BASIC Stamp is a microcontroller with a small, specialized BASIC interpreter (PBASIC) built into ROM.

The third variant is the Javelin stamp. This stamp uses Sun Microsystem's Java programing language instead of Parallax's PBasic

all current PICs are Flash-based, and support in-circuit programming.

stimulus-response

a plan of action

combine the best of both Reactive and Deliberative control

how to interpret sensor data into a mathematical form readable by computers

There are only 3 steps you need to follow: Gather Sensor Data (data logging) Graph Sensor Data Generate Line Equation

Some sensors (such as sonar and Sharp IR) do not work properly at very close range

The motor is driven in either the forward or reverse direction, but will swap polarity if the motor encounters too sudden or great of a load

34164s are undervoltage sensing circuits ("voltage supervisors") designed for use as reset controllers in portable microprocessor based systems. We use them as 3- or 5-volt triggers (here, 3 or 5 fills in the "*" of the part number above), as the heart of the Chloroplast solar engine design.

To use a photodiode in its photoconductive mode, the photodiode is reverse-biased; the photodiode will then allow a current to flow when it is illuminated.

LEDs can be used as photodiodes

FLEDs are light-sensitive, and so flash faster in brighter light

This book provides far more detail on the hardware aspects of robot building than any other I have seen to date and is worth picking up.

"Intermediate Robot Building" offers the kind of real-world knowledge that only an experienced robot builder can offer--the kind of knowledge beginners usually have to learn through mistakes. In this book, you'll learn the value of a robot heartbeat and the purpose of the wavy lines in photocells.