Nearly all the existing designs I found used direct switching of the lights (with no software control in between) and contained manual potentiometers for light sensitivity and overall gain setting. Furthermore, I couldn`t find many references to the frequency filter circuitry explaining the frequencies the circuit was designed to detect and why (it seems most published designs are based on other published designs leading
Click here to download the full size of the above Circuit.
to fairly `sloppy` audio-stage circuitry). So it was time to brush up on op-amp filter design and build something myself. At the local hardware store I found some strings of LED lights (for Christmas decorations) and thought that wiring up a Christmas tree as a colour organ would be a pretty fun thing to do. From that T. O. M. T. E. was born (Tone Operated Microprocessor Tree Enhancement), details of which you can find below along with detailed construction notes. (for the non-Swedish reader, Jultomte is Swedish for Santa Claus, hence the funky abbreviation!) The sound processing circuitry for TOMTE is probably a little over-the-top for the application it is used for here, however it represents a good quality sound-to-light interface design which is probably useful for a number of other light/audio projects I can think of, so even if you don`t intend to build the Xmas decoration I designed, the circuitry is still useful. The microphone is connected to a pre-amplifier (because microphones produce so little electricity) and then on to an amplifier (which has automatic gain control from the microcontroller), the signal is then split into 3 frequency ranges (low, mid, high). Finally the sound is passed through peak-detectors (actually these add a little gain and convert the AC audio signal into DC) which is then measured using the ADC of a PIC18F. The PIC MCU then controls the available lights and the gain of the amplification...
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.....
characters left: