This article describes how to implement a simple, but robust, optical wheel encoder system on a robot that uses hobby servos for two-wheel differential drive. In my case I am using the TJ-PROTM robot platform from MekatronixTM, and some aspects of this article are specific to that platform. However, it should be easy to adapt the hardware and soft
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ware for virtually any robot with an HC11 controller board. This article details the hardware you will need (and where you can buy it), construction methods, and software techniques for implementing navigation by dead reckoning. The software examples are written in Newton Labs` Interactive C ("IC") version 3. 2. To make use of the code samples, I am assuming you know how to load C and binary modules in IC, and that you know how to use the start_process() function. Rather than being heavy in theory, this is written more as a "how to" article. If you are interested in the theory, I would refer you to the Rossum Project article in the Links section at the end. At the heart of this design is a pair of Hamamatsu P5587 photoreflectors (figure 1), one mounted on each side of the robot behind the wheels. Each wheel has a cardboard disc fixed to it with 48 alternating black and white segments. The tiny 5-legged Hamamatsu photoreflector package contains an infrared ("IR") LED and a matching IR phototransistor, both mounted on the top of the device in such a way that the phototransistor will detect reflected IR light emitted from the LED when a bright surface (such as white card) is positioned within a few millimeters of the device. As the wheel turns, and the photoreflector "sees" the white segments between the black segments, the phototransistor outputs a digital pulse train. By counting the pulses, and knowing the number of...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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