G题手写绘图板资料.doc

2013全国大学生电子设计竞赛 PAGE \* MERGEFORMAT1 手写绘图板（G题） 2013年全国大学生电子设计竞赛 手写绘图板（G题） 【本科组】 2013年9月7日 手写绘图板 摘要 手绘板，众所周知，是计算机输入设备的一种，通常是由一块板子和一支压感笔组成。它和本文所介绍的手写绘图板等作为非常规的输入产品相类似，都针对一定的使用群体。手写绘图板主要是利用一根连接到电路的普通表笔在PCB覆铜板上实现简单的绘图及坐标查找功能，并能在表笔接触板上任一点时，明确显示触点的象限位置及坐标值。它包括硬件电路和软件编程两部分。硬件电路主要包括恒流源、二级差分放大、单片机内部A/D采样模块、显示模块。由于敷铜板的电阻很小，所以是采集小信号，然后将采集到的两路电压信号差分放大后经过二级放大得到一个稳定变化的电压值，然后用AD采样经数值变换得到坐标，用低功耗单片机MSP430F14处理，在HB240128液晶显示屏上显示。 采集若干点在液晶上描点还可以绘制一些简单的图形。 【关键字】 MSP430F149 敷铜板 差分放大 AD采样 低功耗 Handwritten Drawing Board Abstract：Hand-painted plates, we all know, is a computer input device, which is usually caused by a board and a pressure sensitive pen components. It is described in this article handwriting and drawing board unconventional inputs such as similar products are used for certain groups. Handwriting mainly using a graphics tablet connected to the circuit common table pen on the PCB CCL simple graphics and coordinate search function, and can contact board office table pen point, clearly shows the location and contact quadrant coordinate values??. It includes hardware circuitry and software programming in two parts. Hardware circuit includes a constant current source, two differential amplifier, internal microcontroller A / D sampling module, display module. Since Bonded Copper resistance is small, so small signal is collected and then collected two amplified differential voltage signal amplified through two changes to get a stable voltage value, and then use AD sampling by numerical transform coordinates, with a low processing power microcontroller MSP430F14 in HB240128 displayed on the LCD. Collected at several points on the LCD can also draw on the tracing point some simple graphics. 【Keywords】 MSP430F149 A/D sampling Copper Differential amplifier  目录 TOC \o 1-3 \h \z \u HYPERLINK \l _Toc366351895 一、引言 PAGEREF _Toc366351895 \h 1 HYPERLINK \l _Toc366351896 1.1 系统总体框架 PAGEREF _Toc366351896 \h 1 HYPERLINK \l _Toc366351897 1.2 本设计应该达到的技术指标 PAGEREF