The robot was controlled with a Motorola 68HC11 on a special MC11 input/output board furnished by the Stanford Smart Product Design Lab (SPDL). The SPDL also furninshed motor controller boards, each consisting of a DS3658 stepper controller, a SN754410 h-bridge, or an LMD18200T h-bridge, with heat sinks and screw-mounts for wires. Infrared sensors
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were used to sense the beacons on the court, thus aiming the robot in the right direction to shoot each time. A set of three sensors with physical reflector/blinders to separate left, right, and narrow-view middle were used to home in on the beacons. Ultrasonic rangefinders were used to sense the distance from the robot to the rear wall of the court, to calculate how far to launch the balls. This also let the robot know what angle it was shooting at, by finding the position perpendicular to the back wall. The catapult`s DC motor used its own separate power supply (at 18V), because it pulled too much peak current to run simultaneously with the other electronics. The circuit`s output is a DC analog voltage corresponding to the light intensity; the DC voltage is given by rectifying and low-pass-filtering the signal after amplification. Note that the rectifying diode is an LED, allowing one to look at the circuit and see the intensity of light being read by the sensor, without the use of measuring instruments. The signal is greatly amplified because it is designed to operate with the sensors eight feet from the beacons. This amplification of a weak signal was also the reason for the second (. 75V) offset voltage: the weak signal, even at its maximum, was below 2. 5V (the first reference voltage) after the voltage drop from the rectifying diode; in order to get any signal, a lower offset voltage had to be used. We used a...
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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