给定多个512点的数组，分别对其进行fft显示其频谱特性并显示频率和幅度坐标（可以通过界面控件选择数组、设定采样时间）-Given an array of more than 512 points, respectively, show the spectrum of their properties for fft and display frequency and amplitude coordinates (you can choose an array of interface cont

制作出来的显示界面，有坐标，相关显示波形-Produced the display interface, with coordinates, related to the waveform display

简单示例，利用QTcreator画圆，固定圆心，圆的半径、圆心可调节，并显示坐标-A simple example, the use of QTcreator Circle, a fixed center, the radius of the circle, the center can be adjusted, and the display coordinate

在LCD屏幕上显示模拟时钟，此程序主要用与arm编程，编译器为arm-linux-gcc 4.4.1，包含画点画线画圆的动态算法，计算角度坐标所需要的sin & cos 表-for lcd Bell