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All Cricket devices have a built-in bidirectional infrared communications channel, which is used for Cricket-to-desktop communication (when downloading programs to a Cricket, or viewing sensor data) and Cricket-to-Cricket communication.

Cricket Logo is based on an iterative, interactive model of project development. It includes a “command center” window; instructions typed into this window are instantaneously compiled, downloaded to a Cricket, and executed, giving the system the flavor of an interpreted software environment such as LISP, BASIC, or FORTH.

The MetaCricket software system is based on a virtual machine, written in PIC assembly language and running on the Cricket, and a compiler for the virtual machine running on a desktop development computer

1381s are CMOS voltage-controlled triggers -- these "gate" a source until the voltage is above some "trip" limit, at which point it is allowed onto a third pin

We use them as 3- or 5-volt triggers

This chip is often considered the heart of Nv net technology

camera-based vision system (for light detection and navigation) two microphones, binaural hearing beat detection (allows pleo to dance and listen to music) - this feature was removed but may be added on again. eight touch sensors (head, chin, shoulders, back, feet) four foot switches (surface detection) fourteen force-feedback sensors, one per joint orientation tilt sensor for body position infrared mouth sensor for object detection into mouth infrared transmit and receive for communication with other Pleos Mini-USB port for online downloads SD card slot for Pleo add-ons infrared detection for external objects 32-bit Atmel ARM 7 microprocessor (main processor for Pleo) 32-bit NXP ARM 7 sub processor (camera system, audio input dedicated processor) four 8-bit processors (low-level motor control)

These bots are powered by a Gold Cap and for a period of about one minute they move, always looking for the brightest lightspot, so in fact they will even follow a lightsource.

All these bots are powered by a 3,3F Gold Cap ( F= farad). You can charge them with a regulated power supply

the two 5 mm red LED's it is capable of following a light source.

All of the procedures take a discrete ``gear'' to specify the speed. The reasons for this are two-fold; first, by limiting the power of the truck, we simplify the interface to children. Secondly, it allows use to calibrate the ``gears'' so that, for example, 10 seconds forward in first gear is the same distance as 10 seconds backward in first gear.

The limitation of LOGO however is the lack of feedback from the environment. There is no way of expressing an event occuring in the outside world.

Simple constructs in iLogo extend the original LOGO language with interactivity capabilities of reading sensors and transfering control to different parts of the program.

Motorcycle lead acid batteries work great for larger low performance type robots. They are great for solar power robots too.

lead acid batteries have the serious problem of being very large and heavy, need to always be kept charged, and do not have the high discharge rates as the more modern batteries.

They have low power capacities, are heavy, have trouble supplying large amounts of current in short time periods, and get expensive to constantly replace

Pleo Technical Specs: Ugobe LifeOS 32 bit Atmel ARM 7 microprocessor - The main processor for Pleo 16 bit sub processor - The processor dedicated to the camera system (4) 8 bit processors that provide the low-level motor control for the servos (35) Sensors including a camera custom designed to fit into Pleo’s very compact body. (4) foot-switches to detect footfalls and being picked up - assists with spatial orientation. (12) capacitive touch sensors (4) legs, (4) feet, back, shoulder, head, chin (2) microphones for directional sound detection (14) “Force” sensors, one per servo, to recognize abuse through force feedback joints. Orientation/tilt sensor IR transceiver for bidirectional data communication with other Pleos. IR interrupter for detection of objects in Pleo’s mouth (14) motors. Standard low voltage DC motors (150) gears and clutches Rechargeable NiMH battery pack USB port with mini USB connector SD/MMC memory card slot

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.

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 basis behavior set of a system provides elements that are not further reducible to each other and that, when composed by sequential or concurrent execution, produce the complete behavior repertoire for the system.

Such basis behaviors are constructed, learned, or evolved from stable, robust interaction dynamics between the agent/robot and its environment, and serve as a substrate for the system's more complex behaviors.

My work generalized the notion of basis behaviors to multi-robot interactions, and demonstrated how a small set of basis behaviors per robot can be used to demonstrate a rich repertoire of individual and group-level behaviors, including following, flocking, homing, herding, aggregation, dispersion, and formations.

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

This chip is great for building robots because it has extensive input/output hardware built right into the chip. This reduces the need for external components.

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.

"Exposing a Flaw: Shoot-Through" describes the serious problem with that circuit, especially when pulsed

Above is an improved version of the circuit, which is now PWM compatible. PWM, coast mode, and the capability to avoid shoot-through are provided by adding a fifth MOSFET (labeled Q5) to the source/ground connections of Q1 and Q3.

The robots do not build a model of their world they simply act in response to the things they encounter whilst existing there.

This form of robotics has proved to be successful in environments that are unknown to the robot, environments that are busy or noisy such as a place with moving objects or people

An important part of the behaviour based theory is "embodiment" This means that a robot must be embodied, have a presence (it is an entity in itself).  In order to react the robot must be surrounded by the real world.