1，Design of Music LED Lighting Controllers
1.1,Theory of music lights rhythm display system
1.1.1,require analytics
When Design of a system, first know that the market demand, to ensure that do such a system is necessary ,second to determine the status of current market and the most recent scientific research to ensure the system of their own design is practical and advanced.
1.1.2 the analytics of system function
First we should be know the purpose and useful for any system. the music light display system is external lights along with music beat to display. For the application of systems is divided into three parts: input parts, mcu part and output part.Input parts refers to the music from the external input to the MCU process. MCU processing refers to deal with the input data with MCU, and for the output display part provides the necessary data and display the required basis. Output part refers to external lights along with music to flash. The designer can be decision of flash way of lights, the flash way has dynamic or static, or color or monochrome. We will talk about the concrete design of the three part:
1.1.3 Design of input part
Because of MCU just only deal with the disperse digital signal, but in real life is more analog signal especially music signal range as 200Hz to 15KHz, which is the practicality of the system to table a proposal and requests. To achieve of disperse of analog for input data. This is to be an easy job to the modulus is more and more mature conversion technology. That is to say we must through the analog-to-digital converter (ADC) converts the input music analog signal to digital, and then into the microcontroller.
1.1.4 MCU process
Input to MCU data stored in the microcontroller’s data store(MCU data memory). Because of display part ask the light flash along with music beat. But the music belongs to the audio signal. corresponding to the beat of the music and audio signal frequency, so in order to achieve unity displayed with the beat, it is necessary to discrete digital signal , digital signal processing technology and audio signal frequency is currently the most commonly used is the discrete Fourier transform(DFT).
1.1.5 output display part
Design idea is relatively simply and straightforward for output display part. which is easy to implement. Consider to the frequency range of the actual music signal is 200Hz ~ 15KHz,Through the A / D converter after, sampling the analog frequency will correspond to the digital frequency K value , i.e., a certain range of values K (where K the maximum value is carried out by DFT points). This system is realized by using different colors of the diode consists of a 5 x 7 dot matrix. With 7 diodes of different colors to represent different frequency, which the digital frequency value of K is divided into 7 equal parts, each segment of K value with diode represents a color. Each color diodes have 5 used to represent the amplitude, the amplitude is divided into 5 sections to achieve different. Because the signal amplitude of the MCU 5V maximum, when the range of 0 ~ 1V, the corresponding frequency diode light one; is 1 ~ 2V, bright two diodes; for 2 ~ 3V, bright three diodes; for 3 ~ 4V, bright four diodes; 4 ~ 5V, bright five diodes.
The above is a general idea of the topic(LED contrller),