As the robot`s battery voltage would slowly drop, the servo`s centre point would drift. After a while, one or both servo motors would begin to creep even though they should have been stopped. Secondly, servos are designed to hold a position and not a set speed. Normally the position would be set by the length of the control pulse. 1. 0mS wou
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ld be one extreme and 2. 0mS the other. Normally 1. 5mS would be in the middle. After being modified for continous rotation, any pulse length shorter than 1. 5mS causes the servo to rotate one direction, and anything longer causes the servo to rotate in the other direction. The magnitude of the pulse width deviation from 1. 5mS has an affect on the rotation speed, but it`s a bit variable and not linear. For this project I decided to use some 1:100 gear head motors I bought from Pololu. com. I also decided that I needed feedback so I could accurately know how fast the wheels were actually rotating. One way to do this is to use optical sensors that detect a pattern attached to the wheel. If there are two sensors and they are positioned correctly then you can implement something called quadrature detection (like was used in the old wheeled mice). Then you can tell not only the amount of rotation by counting pulses but also its direction by observed the phase between the two sensors. Fitzy and Carraldo are using the MicroChip dsPIC33FJ64MC804 as their brain. The MC variant includes dual built in quadrature encoders that are just what I need to turn pulses from optical sensors into direction and distance. Now I`ll be the first to admit that mechanical design is not my strongest skill. When designing the PCB I had only located the position of the motors but I hadn`t really decided exactly how I would attach them. Caught up in the...
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....
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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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