This project creates a RGB LED VU Meter which is controlled via USB by a Windows 7 or Vista host machine. The project serves several purposes: Firstly, it demonstrates how to read audio information from the Windows machine and pass this over USB to the device (which is a question which popped up several times after my USB Performance Monitor proje
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ct). Secondly, it implements an open source TLC5940 driver. Although a library has been available for the AVR microcontroller, I wasn`t able to find an open source library for the PIC. Hopefully this demonstration will be useful to anyone wanting to control a large number of LEDs with PWM brightness control. The hardware in this project is very straight forward. The demonstration board consists of a 5V regulator (switching), a PIC18F2550 with the required USB components, 3xTLC5940 16 channel serial LED drivers with PWM and 16 high intensity RGB LEDs. The only real thing of `note` in the circuit design is the two large capacitors placed next to the crystal oscillator. The high-speed switching performed by the 5940s when controlling the LEDs via PWM generates a lot of power-rail noise (and I mean a lot!). The two capacitors help to ensure that the PIC`s timing circuitry remains stable. During breadboarding the 5940s would cause the PIC to reset as well as other nasty side-effects. As I wanted to test and demonstrate cascaded TLC5940s the LEDs are not multiplexed. Each LED is under direct control. However, given the big amount of brightness generated by the LEDs the end result would not suffer due to multiplexing and the code can be readily adapted if required. The firmware is based on the software available from my Open Source Framework for USB Generic HID devices based on the PIC18F and Windows. I`ve added two layers to this...
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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