FFT在单片机上的实现毕业设计.doc

FFT在单片机上的实现 摘 要关 键 词： THE REALIZATION OF FFT IN THE MICROCONTROALER ABSTRACT Audio signal analyzer is a kind of device which can be widely found in various of audio, mixing and recording devices, and can sampling and analysis of the spectrum of the input have an intuitive audio signal and displays it on the display in real-time, people can are listening to Music for music when high frequency understanding. What presented in this article is just such an audio signal analysis system. The hardware of the system are formed with three parts: the signal conditioner, the control processor?and? the display module. Signal conditioning circuit makes the signal of 300mV ~ 3V AC audio signal available for inputting. In this system,we only process with single-channel signal: When the voltage is lower the system uses LM324 op amp to gain voltage, and as to signals more than 12800Hz it filters them. In addition the system sets an output audio interface for monitoring. The control processor of the system is the 51 cores 1T MCU STC12C60A5S2, with 32.768MHz crystal frequency. The device comes with 8-channel 10-bit high-speed ADC, where only one channel ADC high 8. The signal collected 32 points in consecutive floating-point FFT operation. A complete sampling time is 1.25ms, the maximum sampling frequency is 25600Hz, and the distinguish frequency is 800Hz ~ 12800Hz, with 16 levels. The main display section is 1602 LCD screen, which has 2 rows × 16 columns - 8 × 5 dot display matrix. 16 points to the column height spectrum will be displayed on the display. The process of setting of the frequency drop in the perception of better effect. There is also contrast adjustment resistor, which makes the screen contrast adjustable. KEY WORDS：FFT目 录第1章 绪论 1 §1.1 研究的背景及意义 1 §1.1.1 课题研究背景 1 §1.1.2 课题研究意义 1 §1.2 课题发展的状况 1 §1.3 设计任务 2 第2章 系统方案设计 3 §2.1 系统方案设计 3 §2.2 系统硬件的选择 3 §2.2.1 处理器的比较与选择 3 §2.2.2 采样模块的确定 4 §2.2.3 显示器件的比较和选择 4 第3章 系统硬件设计 5 §3.1 单片机STC12C5A60S2 5 §3.1.1 单片机STC12C5A60S2功能简介 5 §3