超声波传感器适用于对大幅的平面进行静止测距。普通的超声波传感器测距范围大概是 2cm~450cm，分辨率3mm（淘宝卖家说的，笔者测试环境没那么好，个人实测比较稳定的 距离10cm~2m 左右，超过此距离就经常有偶然不准确的情况发生了，当然不排除笔者技术 问题。） 测试对象是淘宝上面最便宜的SRF-04 超声波传感器，有四个脚：5v 电源脚（Vcc），触发控制端（Trig），接收端（Echo），地端（GND） 附:SRF 系列超声波传感器参数比较 模块工作原理： 采用IO 触发测距，给至少10us 的高电平信号； 模块自动发送8个40KHz 的方波，自动检测是否有信号返回； 有信号返回，通过IO 输出一高电平，高电平持续的时间就是超声波从发射到返回的时间．测试距离=(高电平时间*声速(340m/s))/2; 电路连接方法 Arduino 程序例子： constintTrigPin = 2; constintEchoPin = 3; floatcm; voidsetup() { Serial.begin(9600); pinMode(TrigPin, OUTPUT); pinMode(EchoPin, INPUT); } voidloop() { digitalWrite(TrigPin, LOW); //低高低电平发一个短时间脉冲去TrigPin delayMicroseconds(2); digitalWrite(TrigPin, HIGH); delayMicroseconds(10); digitalWrite(TrigPin, LOW); cm = pulseIn(EchoPin, HIGH) / 58.0; //将回波时间换算成cm cm = (int(cm * 100.0)) / 100.0; //保留两位小数 Serial.print(cm); Serial.print("cm"); Serial.println(); delay(1000); }
上传时间： 2013-11-01
上传用户：xiaoyuer
The code assumes a two-dimensional computational domain with TMz polarization (i.e., non-zero field Ez, Hx, and Hy). The program is currently written so that the incident field always strikes the lower-left corner of the total-field region first. (If you want a different corner, that should be a fairly simple tweak to the code, but for now you ll have to make that tweak yourself.) I have attempted to provide copious comments in the code and hope that a knowledgeable C programmer can quickly map the approach as described in the paper to what is in the program.
标签： two-dimensional computational polarization non-zero
上传时间： 2013-12-13
上传用户：cylnpy
The tar file contains the following files: ptfsf.c: heart of the perfect TFSF code ptfsf.h: header file for same ptfsf-demo.c: FDTD code which demonstrates use of perfect TFSF code. Essentially this program used to generate results shown in the paper ptfsf-file-maker.c: code to generate an incident-field file using the "perfect" incident fields ptfsf-demo-file.c: FDTD code which uses the perfect incident fields stored in a file fdtdgen.h: defines macros used in much of my code Makefile: simple make-file to compile programs Also include are some simple script files to run the programs with reasonable values. The code assumes a two-dimensional computational domain with TMz polarization (i.e., non-zero field Ez, Hx, and Hy). The program is currently written so that the incident field always strikes the lower-left corner of the total-field region first. (If you want a different corner, that should be a fairly simple tweak to the code, but for now you ll have to make that tweak yourself.)
标签： ptfsf following the contains
上传时间： 2013-11-28
上传用户：风之骄子
深圳市秋田视佳实业有限公司的液晶程序，HY－12864T－201，单片机模拟串口方式的C51程序
标签： 液晶程序
上传时间： 2017-07-26
上传用户：qq1604324866
本人所写的Hy计算器，已在安智市场发布，在此公开界面布局代码，并配注释。该界面布局通过自动压缩计算器显示屏的大小，可以使得按键的布局在不同分辨率手机上相对保持不变。
标签： 安卓计算器布局
上传时间： 2015-05-28
上传用户：Star25820
Hy-SRF05的相关介绍，相信你会需要的，能帮到你我很高兴
标签： 超声波
上传时间： 2017-04-29
上传用户：cc-pdd
