Driving LEDs at a regulated current from low supply voltages can be difficult because minimal overhead voltage is available for control circuits. A current-mirror architecture is suitable but usually works only with ICs with well-matched transistors…

说在前面:上一篇介绍了无线LED闪烁实现的OSAL部分,本篇介绍如何实现无线数据收发及数据处理: 上一篇是用SI跟着流程查看源码,我个人认为以架构的思维去了解代码能让人更清晰 ::ZMain.c程序入口文件 这里chipcon_cstartup.s51是汇编的启动文件,ZMain.c相当于main文件,里面有main函数: int main( void ) { osal_int_disable( INTS_ALL );// Turn off interrupts 关中断 HAL_BOARD_IN…

1.Zigbee协议栈简介 协议是一系列的通信标准,通信双方需要按照这一标准进行正常的数据发射和接收.协议栈是协议的具体实现形式,通俗讲协议栈就是协议和用户之间的一个接口,开发人员通过使用协议栈来使用这个协议,进而实现无线数据收发. 如图1所示:Zigbee协议分为两部分,IEEE 802.15.4定义了PHY(物理层)和MAC(介质访问层)技术规范:Zigbee联盟定义了NWK(网络层).APS(应用程序支持层).APL(应用层)技术规范.Zigbee协议栈就是将各个层定义的协议都集合在一起,…

作者:宋老师,华清远见嵌入式学院讲师. ZigBee的基本流程:由协调器的组网(创建PAN ID),终端设备和路由设备发现网络以及加入网络. 基本流程:main()->osal_init_system()->osalInitTasks()->ZDApp_Init(),进协议栈初始化函数ZDApp_Init(). 1.1 进入程序入口main(). ZMain.c中 C++ Code int main( void )         {                 // Turn of…

一.Zigbee协议 Zigbee是IEEE 802.15.4协议的代名词,是一种短距离.低功耗的无线通信技术.这一名称来源于蜜蜂的八字舞,因为蜜蜂(bee)是靠飞翔和“嗡嗡”(zig)地抖动翅膀的“舞蹈”来与同伴传递花粉所在方位信息.Zigbee的特点是近距离.低复杂度.自组织.低功耗.低数据速率.低成本,所以特别适合用来组建无线传感器网络. Zigbee的应用领域包括: 家庭和楼宇网络:空调系统的温度控制.照明的自动控制.窗帘的自动控制.煤气计量控制.家用电器的远程控制等: 工业控制:各种监…

0xWS2812 STM32 driver for WS2812(B) RGB LEDs 0xWS2812 pronounced "hex-WS2812" This code aims at providing a basic interface to the WS2812(B) individually addressable RGB LEDs by WorldSemi. The code outputs 16 parallel data streams to 16 parallel…

[TI博客大赛][原创]LM3S811之基于PWM的DAC http://bbs.ednchina.com/BLOG_ARTICLE_3005301.HTM http://www.fpga4fun.com/PWM_DAC_3.html One-bit DAC Take one pin of an FPGA, connect a speaker and listen to an MP3? Easy. Here, we'll use a PC to decode an MP3, and then s…

The achievable accuracy for systems with multiple ADCs depends directly on the reference voltages applied to the ADCs. Medical-ultrasound-imaging systems, for example, commonly include a large number of ADCs in the system's beam-former electronics, w…

LDO current regulator for power LED Challenge You've got a power LED? Great! Build a flash light! What does the spec say? "Voltage: 3.6 .. 3.8 V, power 3 W." Okay. This means that it draws some 800 mA. Three mignon cells give 4.5 V for at least…

The popular USB interface can charge a portable device while transferring data. But for high-capacity batteries, the 500-mA output current of USB hosts and powered hubs greatly extends the charging time. (Unpowered USB hubs supply no more than 100 mA…

The USB (Universal Serial Bus) specification requires a connected USB device to present a load to the host or hub of no greater than 10 µF in parallel with 44Ω, including the effects of any bypass capacitance visible through the device’s voltage regu…

Sound card based RFID sniffer/emulator (Too tired after recon.cx to do draw the schematics better than that :) Stay tuned for the next version including Tag emulation.) baudline FFT signal analyzer for sniffing LF RFID tags using our sound card based…

RFID读写器的工作原理 RFID的数据采集以读写器为主导,RFID读写器是一种通过无线通信,实现对标签识别和内存数据的读出和写入操作的装置. 读写器又称为阅读器或读头(Reader).查询器(Interrogator).读出装置(Reading Device). 扫描器(Scanner).通信器(Communicator).编程/编码器(Programmer)等等. 读写器工作原理 RFID读写器的基本原理是利用射频信号与空间耦合传输特性,使电子标签与阅读器的耦合元件在射频耦合通道内进行能量传…

This 125 kHz RFID reader http://www.serasidis.gr/circuits/RFID_reader/125kHz_RFID_reader.htm http://www.serasidis.gr/circuits/RFID_reader/images/125kHz_RFID_reader_schem.GIF I will try to explain with simple words how the RFID works. The ATtiny13 use…

---恢复内容开始--- OBDII Interface Project When I can ever find enough time away from schoolwork, I try to work on an OBDII compliant portable ScanTool. However, with my current course load and lab projects progress on this project has been very slow. I fi…

Transistor Tutorial Summary Transistor Tutorial Summary Bipolar Junction Transistor Tutorial We can summarise this transistors tutorial section as follows: The Bipolar Junction Transistor (BJT) is a three layer device constructed form two semiconduct…

前几天收到 Arduino M0,试各项功能都正常,可就是串口监视器/串口助手不能显示程序里打印的输出,好生奇怪,各种换波特率各种PC串口程序换着试,资料不多,官方资料也只说到 Serial1 用于 pin 0 1 的(实际上测试的时候提示 Serial1 没有声明),Serial 用于 USB 通信,根本只字未提 SerialUSB 的事,直到今天,哦不,是昨天了,下午在群里提问,“忠忠”回复有一个 SerialUSB 用于 USB 的串口通信,这才知道了这个事.真是好坑人啊. 官网链接:ht…

Arduino语言介绍 Arduino语言是建立在C/C++基础上的,其基础是C语言,Arduino语言只不过把AVR单片机(微控制器)相关的一些参数设置都函数化,不用我们去了解他的底层,让不了解AVR单片机(微控制器)的朋友也能轻松上手. 基础C语言 关键字: if              条件选择语句 if...else       条件选择语句 for             for 循环语句 switch case     并行多分支选择 while           循环语句 do…

Voltage Translation for Analog to Digital Interface ADC http://openschemes.com/2010/03/23/zeroplus-logic-cube-review-and-teardown/ LAP 16032 has 4.5MBIT SRAM and can aquire up to 128k per chn, now my LAP 16032 has 18MBIT SRAM It’s a good product, and…

1.从OrCAD PSpice help文档: 2.国外网站的相关介绍: The DC characteristics of the diode are determined by the parameters IS, N, and the ohmic resistance RS. Charge storage effects are modeled by a transit time, TT, and a nonlinear depletion layer capacitance which…

Arduino语言 Arduino语言是建立在C/C++基础上的,其实也就是基础的C语言,Arduino语言只不过把AVR单片机(微控制器)相关的一些参数设置都函数化,不用我们去了解他的底层,让我们不了解AVR单片机(微控制器)的朋友也能轻松上手. 在与Arduino DIYER接触的这段时间里,发现有些朋友对Arduino语言还是比较难入手,那么这里我就简单的注释一下Arduino语言(本人也是半罐子水,有错的地方还请各位指正). 基础C语言 关键字: if...else 必须紧接着一个问题表…

转自:http://blog.csdn.net/jmq_0000/article/details/7536805#t136 Video for Linux Two API Specification Revision 0.24 Michael H Schimek <mschimek@gmx.at> Bill Dirks Hans Verkuil Martin Rubli Copyright © 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 20…

http://en.wikipedia.org/wiki/Motherboard_form_factor Computer form factor From Wikipedia, the free encyclopedia   (Redirected from Motherboard form factor)   For computers form factors both larger and smaller than desktop personal computers, see list…

A processor's performance state may be adjusted based on processor temperature. On transitions to a lower performance state due to the processor getting hotter, the processor's frequency is reduced prior to reducing the processor voltage. Thus, the p…

@http://www-cs-faculty.stanford.edu/people/karpathy/cvpr2015papers/ CVPR 2015 papers (in nicer format than this) maintained by @karpathy NEW: This year I also embedded the (1,2-gram) tfidf vectors of all papers with t-sne and placed them in an interf…

https://en.wikipedia.org/wiki/Secure_Digital#Technical_details Secure Digital (SD) is a non-volatile memory card format developed by the SD Card Association (SDA) for use in portable devices. The standard was introduced in August 1999 by joint effort…

Driver Amplifiers For Analog-To-Digital Converters What amplifiers are used to drive analog-to-digital converters (ADCs)? Possibilities include single-ended and differential inputs and outputs, plus voltage feedback (VFB) or current feedback (CFB) in…

Building a Differential Amplifier An op-amp with no feedback is already a differential amplifier, amplifying the voltage difference between the two inputs. However, its gain cannot be controlled, and it is generally too high to be of any practical us…

Radio Basics for RFID The following is excerpted from Chapter 3: Radio Basics for UHF RFID from the Book, The RF in RFID: Passive UHF RFID in Practice by Daniel M. Dobkin. Order a copy of The RF in RFID: Passive UHF RFID in Practice before December 3…

不同频段的RFID产品会有不同的特性,本文详细介绍了无源的感应器在不同工作频率产品的特性以及主要的应用. 目前定义RFID产品的工作频率有低频.高频和甚高频的频率范围内的符合不同标准的不同的产品,而且不同频段的RFID产品会有不同的特性. 其中感应器有无源和有源两种方式,下面详细介绍无源的感应器在不同工作频率产品的特性以及主要的应用. 1． 低频(从125KHz到134KHz)   其实RFID技术首先在低频得到广泛的应用和推广.该频率主要是通过电感耦合的方式进行工作, 也就是在读写器线圈和感应…