Well, I guess every hobbyist some when comes up with ideas of controlling or measuring something with a PC. Of course the idea is tempting, there are so many easy-to-learn program languages available for PCs today that almost everyone can write the software to switch on the light when he is on vacation, to control these cute little toy robots or t
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o measure the amount of rain over the day. So if you are a somewhat advanced hobbyist, the application is only limited by your fantasy (i. e. the sky is the limit). But: How can we close the gap between a few lines of software code and a real electrical signal outside of the computer Of course there are many solutions to this problem, many of them require serious "hacking" to access one of the i/o ports of a computer. (Especially Windows NT4 required very advanced programming skills if you wanted to use i/o ports for non-standard applications). One port that is easy to access from a software point of view is the serial RS232 port (COM1, COM2, etc. ). All modern software development tools support the RS232 port, so its usually no problem at all to send or receive data via this port. What makes the RS232 very unattractive for hobbyists is the fact the data bits are in a serial time synchronous format with critical timing and a relatively complex start/stop-bit overhead. To make it even worse the bit levels are -12V for high and +12V for a low bit, so connecting RS232 signals to a circuit that uses 5V logical levels is not trivial either. Simply forget about connecting the RS232 directly to a relay driver stage or things like that. And that is where this circuit comes in. It converts a RS232 bit stream into standard digital signal inputs and outputs. It even provides you with a couple of 10bit ADCs so you can read analog...
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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