Digitemp Jr. is a device that is designed to measure
and report ambient temperature. When connected to
an RS-232 port on any PC, it will periodically measure
and report in ASCII form the ambient temperature in
degrees Celsius. These temperature readings can be
monitored with any terminal program. If the terminal
program supports capture to disk, the temperature
readings can be saved to disk for further analysis with
a spreadsheet program or other data analysis tool. The
simple ASCII output format of Digitemp Jr. makes it relatively
easy to write custom software for receiving,
recording, and analyzing ambient temperature data.
Best of all, Digitemp Jr. requires no external power supplies
or batteries. It is powered directly by the RS-232
port.
首先研究CAN總線和SAE J1939協(xié)議，提出一種基于MC9S12HZ256微控制器的總線式汽車數(shù)字儀表解決方案。詳細(xì)介紹SAE J1939協(xié)議的報(bào)文幀格式及應(yīng)用層協(xié)議中發(fā)動(dòng)機(jī)相關(guān)參數(shù)的定義，以及步進(jìn)電機(jī)及其驅(qū)動(dòng)和車速信號的處理方法。該數(shù)字儀表系統(tǒng)硬件平臺由微處理器和信號采集和信息處理及顯示等模塊組成。軟件設(shè)計(jì)部分編程實(shí)現(xiàn)了對CAN總線和各傳感器數(shù)據(jù)的讀取、處理。該系統(tǒng)能夠?qū)崟r(shí)反映車輛工況。
Abstract:
In this paper，CAN bus and SAE J1939protocol are researched，and a vehicle digital instrument solution based on MC9S12HZ256MCU is proposed.The message frame format and some engine-related parameters’definition in SAE J1939application layer protocol are introduced in detail.Stepper motor and its driver，the methods of speed signal process-ing are also introduced.The hardware platform of vehicle digital instrument is composed by MCU，signal acquisition mod-ule，and signal processing and displaying module.Data receiving and processing from CAN bus and sensors are accom-plished by programming，and vehicle condition can be reflected in real-time.
介紹了基于單片機(jī)C8051F020的通用串口適配器的設(shè)計(jì)與實(shí)現(xiàn)方法，即由單片機(jī)控制的智能化一對多口收發(fā)信號轉(zhuǎn)換器。通過采用C51對單片機(jī)進(jìn)行編程，控制與RS-232（標(biāo)準(zhǔn)RS-232電平）、RS232(TTL電平)、RS-422接口的數(shù)據(jù)通信；采用C++ Builder作為開發(fā)平臺，通過RS-232接口實(shí)現(xiàn)上位機(jī)對適配器各個(gè)通信端口的控制。
Abstract:
Design and realization of a universal serial port adapter based on the MCU C8051F020 are introduced.The adapter is an intelligent one-to-more receiving and transmitting signal converter controlled by the MCU. By programming the MCU with the language C51,MCU control data communication between the MCU and RS-232(RS-232 level),RS-232(TTL level),RS-422 port; Using C++ Builder as the development plane, by one RS232 port, the upper PC can control each of the communication port of the adapter.
介紹了CAN總線和P87C591單片機(jī)的特點(diǎn)，給出了基于P87C591單片機(jī)的信號采集節(jié)點(diǎn)的軟、硬件設(shè)計(jì)，指出了硬件電路設(shè)計(jì)中應(yīng)注意的問題，在軟件設(shè)計(jì)中重點(diǎn)介紹了節(jié)點(diǎn)初始化、報(bào)文發(fā)送和報(bào)文接收等子程序。
Abstract:
The features of CAN Bus and the microcontroller P87C591 are introduced, and the design of hardware circuit and soft configuration of the signals collection node based on P87C591 are presented. The problems in designing hardware circuit are discussed.Initialization subprogram, transmiting subprogram and receiving subprogram are emphasized in soft configuration.
針對UHF讀寫器設(shè)計(jì)中，在符合EPC Gen2標(biāo)準(zhǔn)的情況下，對標(biāo)簽返回的高速數(shù)據(jù)進(jìn)行正確解碼以達(dá)到正確讀取標(biāo)簽的要求，提出了一種新的在ARM平臺下采用邊沿捕獲統(tǒng)計(jì)定時(shí)器數(shù)判斷數(shù)據(jù)的方法，并對FM0編碼進(jìn)行解碼。與傳統(tǒng)的使用定時(shí)器定時(shí)采樣高低電平的FM0解碼方法相比，該解碼方法可以減少定時(shí)器定時(shí)誤差累積的影響；可以將捕獲定時(shí)器數(shù)中斷與數(shù)據(jù)判斷解碼相對分隔開，使得中斷對解碼影響很小，實(shí)現(xiàn)捕獲與解碼的同步。通過實(shí)驗(yàn)表明，這種方法提高了解碼的效率，在160 Kb/s的接收速度下，讀取一張標(biāo)簽的時(shí)間約為30次/s。
Abstract:
Aiming at the requirement of receiving correctly decoded data from the tag under high-speed communication which complied with EPC Gen2 standard in the design of UHF interrogator， the article introduced a new technology for FM0 decoding which counted the timer counter to judge data by using the edge interval of signal capture based on the ARM7 platform. Compared with the traditional FM0 decoding method which used the timer timed to sample the high and low level， the method could reduce the accumulation of timing error and could relatively separate capture timer interrupt and the data judgment for decoding， so that the disruption effect on the decoding was small and realizd synchronization of capture and decoding. Testing result shows that the method improves the efficiency of decoding， at 160 Kb/s receiving speed， the time of the interrogator to read a tag is about 30 times/s.
Linux 虛擬網(wǎng)絡(luò)接口 實(shí)例
In the Linux (or Unix) world, most network interfaces, such as eth0 and ppp0, are associated with a physical device that is in charge of transmitting and receiving data packets. However, some logical network interfaces don t feature any physical packet transmission. The most well-known examples of these "virtual" interfaces are the shaper and eql interfaces.
This book describes the following communications applications: Mail, Message Handler( MH), Transmission ControlProtocol/ Internet Protocol(TCP/ IP), Basic Networking Utilities( BNU), and Asynchronous Terminal Emulation( ATE). It provides overviews, concepts, and procedures on receiving and sending mail and messages, transferring files( ftp command), printing files from and to a remote system, running commands on other systems, communicating between local and remote systems, and customizing the communications environment.
TI DSP2812 can總線程序,可以用這個(gè)程序設(shè)計(jì)can總線收發(fā)數(shù)據(jù),已經(jīng)在自己的開發(fā)板上測試過,運(yùn)行良好-TI DSP2812 the can main line procedure, may use this programming can main line receiving and dispatching data, has already tested on own development board, the movement is good
This project aim was to build wireless software modem for data communication
between two computers using an acoustic interface in the voice frequency range (20Hz–
20,000Hz). The transmitting antenna is a speaker (frequency response of: 90Hz –
20,000Hz) and the receiving antenna is a microphone (frequency response of: 100Hz –
16,000Hz). The test files used as information files were text files.
This goal was attained both in an incoherent scheme and in a coherent scheme.
Build under Matlab code, our modem uses OFDM (orthogonal frequency division
multiplexing) modulation, synchronization by LMS sequence, channel estimation (no
equalizer) via pilot tones. The symbols are either PSK or ASK for a constellation size of
2 or 4. To optimize the probability of error, these symbols were mapped using Gray
mapping.
Report
SMSTransceiver (short message service transmitter and receiver [transceiver]) is a tool for sending and receiving SMS via a serial or infrared connection between PC and a mobile phone.
