摘要
系统能够实现手写绘图板功能,当触笔接触覆铜板时,能够通过显示屏LCD12864显示出触笔所在的坐标位置、象限以及触笔轨迹等信息。电路设计以单片机STC89C58为核心,基于惠斯通电桥原理,从覆铜板4个引脚分别引出4路信号,经仪表放大器INA128进行10 000倍差分放大进行PCB坐标定位,然后由TLC2543进行A/D转换,在单片机中建立数据库,用查表法在LCD12864液晶屏上进行显示。实验表明,所设计的手写绘图板系统能基本完成题目设计要求,并且有进一步开发与完善的空间。
The system can realize the function of handwritten drawing board. When the stylus touches the PCB board, the cor- responding coordinate and the quadrant will be displayed on a display LCD12864.What is more, the stylus＇s circular path will be displayed, too. The whole designing scheme is mainly controlled by STC89C58 single chip microcomputer. Using the principle of Wheatstone bridge, a four-way signal is produced respectively from the PCB＇s four pins. The produced weak signals will be ampli- fied about 10 000 times by four instrumentation amplifiers INA128. Then the amplified signals will be converted by ADC TLC2543. Lastly, a database is established in the MCU and it＇s able to confirm the stylus position by the look-up table. The designing de- mands can basically satisfied using this planning and the syetem can be further improved.
出处
《电子技术应用》
北大核心
2014年第9期81-84,共4页
Application of Electronic Technique
基金
咸阳师范学院教研基金项目(13XSYK015)
陕西省教育厅项目(09jk808)
