為了使音頻信號分析儀小巧可靠,成本低廉,設計了以2片MSP430F1611單片機為核心的系統。該系統將音頻信號送入八階巴特沃茲低通濾波器,對信號進行限幅放大、衰減、電平位移、緩沖,并利用一單片機負責對前級處理后的模擬信號進行采樣,將采集得到的音頻信號進行4 096點基2的FFT計算,并對信號加窗函數提高分辨率,另一單片機負責對信號的分析及控制顯示設備。此設計精確的測量了音頻信號的功率譜、周期性、失真度指標,達到較高的頻率分辨率,并能將測量結果通過紅外遙控器顯示在液晶屏上。
Abstract:
o make the audio signal analyzer cheaper, smaller and more Reliable, this system sends the audio signal to the eight-order butterworth filter, and then amplifies, attenuates, buffers it in a limiting range, transfers the voltage level of the signal before utilizing two MSP430F1611 MCU to realize the audio analysis. One is charged for sampling and dealing with the processed audio signal collected by the 4096 point radix-2 FFT calculation and imposes the window function to improve the frequency resolution. The other one controls the display and realizes the spectrum, periodicity, power distortion analysis in high resolution which is displayed in the LCD screen through the infrared remote control.
設計一種基于P89V51RD2的功率因數測量儀,采用光電隔離器和專用數碼管驅動器。該測量儀是以增強型單片機P89V51RD2為核心,大大簡化系統硬件設計。而軟件部分采用模塊化設計思想,采用中值濾波和小數補償算法,實現功率因數的高精度測量。實驗測試表明,該功率因數測量儀測量精度高,運行穩定可靠。
Abstract:
A power-factor measurement instrument based on P89V51RD2is designed,which uses optical coupler and specific LED drive chip.The power factor measurement instrument uses P89V51RD2as a core of which greatly simplifies the system design.Furthermore,modularization software is developed in detail.The high precision power-factor measuring system is realized by the center value filter and fractional compensation algorithm.Experiments manifests that the power- factor measurement instrument is high precision,steady and Reliable.
為解決傳統可視倒車雷達視頻字符疊加器結構復雜,可靠性差,成本高昂等問題,在可視倒車雷達設計中采用視頻字符發生器芯片MAX7456。該芯片集成了所有用于產生用戶定義OSD,并將其插入視頻信號中所需的全部功能,僅需少量的外圍阻容元件即可正常工作。給出了以MAX7456為核心的可視倒車雷達的軟、硬件實現方案及設計實例。該方案具有電路結構簡單、價格低廉、符合人體視覺習慣的特點。經實際裝車測試,按該方案設計的可視倒車雷達視場清晰、提示字符醒目、工作可靠,可有效降低駕駛員倒車時的工作強度、減少倒車事故的發生。
Abstract:
A new video and text generation chip,MAX7456,was used in the design of video parking sensor in order to simplify system structure,improve reliability and reduce cost. This chip included all the necessary functions to generate user-defined OSDs and to add them into the video signals. It could be put into work with addition of just a small number of resistances and capacitors. This paper provided software and hardware implementation solutions and design example based on the chip. The system had the characteristics of simplicity in circuit structure,lower cost,and comfort for the nature of human vision. Loading road test demonstrates high video and text display quality and Reliable performance,which makes the driver easy to see backward and reduces chance of accidents.
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根據看門狗電路的原理,設計出簡單適用、性能可靠的1TrL型看門狗電路以及價格低廉、性能可靠的微功耗CMOS型看門狗電路,同時還介紹了常用的uP監視器O型看門狗電路。關鍵詞:看門狗電路;1TrL型;CMOS型Abstract:In accordance with the principle of WDT (Watch Dog Timer 1circuit,design a,IT.L type WTD circuit,it is a dimple an d applicable an d Reliable on performanceo Design a CMOS type WTD circuit,it is low prices and mini-power consumption。Also the article describes a common uP type WTD circuit。Key word:WDT circuit;TFL type;CMOS typ e
基于PIC單片機的脈沖電源:設計了一種金屬凝固過程用脈沖電源。該電源采用PIC16F877作為主控芯片,實現對窄脈沖電流幅值的檢測,以及時電流脈沖幅值根據模糊PID算法進行閑環控制。使用結果表明:該電源的輸出脈沖波形良好,電流幅值穩定,滿足合金材料凝固過程的工藝要求且運行穩定可靠。關鍵詞:脈沖電源;PIC16F877單片機;模糊PID;閑環控制
Abstract:A kind of pulse power supply was designed which uses in the metal solidification process ..I11is power supply used PIC16F877 to take the master control chip reali on to the narrow pulse electric current peak-to-peak value examination,carried on the closed-loop control to the electric current pulse peak-to-peak value basis fuzzy PID algorithm.The use result indicated ,this power supply output se profile is good,and the electric current peak-to-p~k value is stable,It satisfies the alloy material solidification process the technological requirement and movement stable Reliable,Key words:p se po wer supply;PIC16F877single-chip microcontroller;f r PID;closed-loop control
基于多點網絡的水廠自動監控系統設計Design of MPI Based Automatic Monitoring and Control System in Water Works劉 美 俊(湖南工程學院,湘潭411101)摘要針對水廠工作水泵多、現場離控制站距離遠的特點,提出了一種基于MPI多點網絡的自動監控系統的設計方法,分析了系統的工作原理,介紹了系統中數據的采集與處理、主站與從站的通信原理以及系統軟件的設計。由于這種系統的主、從站PLC之間采用MPI網絡通信,具有運行可靠、性能價格比高的特點,所以適用于中小規模水廠的分布式監控場合。關鍵詞多點網絡主站從站監控系統Abstract Ina ccordancew ithth efe atuersof w aterw orks,i. e. ,manyp umpsin o perationa ndth ep umps, farfor mt hec ontrolst ation,th em ethodo fdesigninga na utomati(〕monitoringa ndc ontorlsy stemb asedo nM PIis p resented.Th eo perationalpr incipleo fth esy stemi san alyzed,th ed atac olection,data processing; communication between master station and slave station as wel as design and system software are discussed. Because MPI network communicationis used among master station, slave stations and PLC, the system is Reliable and high cost-efective. It is, suitable for smal and mediumsized water works for distrbuted monitoring and control.Keywords MPI Masterst ation Slaves tation Monitoringa ndc ontorlsy stem
自來 水 廠 的自動控制系統一般分為兩大部分,一對組態硬件要求較高,投資較大。相對而言,MPI網是水源地深水泵的工作控制,一是水廠區變頻恒壓供絡速度可達187.5 M bps,通過一級中繼器傳輸距離可水控制,兩部分的實際距離通常都比較遠。某廠水源達Ikm 。根據水廠的具體情況,確定以MPI方式組地有3臺深井泵給水廠區的蓄水池供水。水廠區的成網絡,主站PLC為S7-300系列的CPU3121FM,從任務是對水池的水進行消毒處理后,通過加壓泵向管站為S7-200系列的CPU222。這樣既滿足了系統要路恒壓供水。選用Siemens公司的S7系列可編程控求,又相對于Profibus網絡節省了三分之一的成本,制器(PLC)和上位機組成實時數據采集和監控系統, 這種分布式監控系統具有較高的性能價格比。系統對深水泵進行遠程控制,對供水泵采用變頻器進行恒中PLC的物理層采用RS - 485接口,網絡延伸選用壓控制以保證整個水廠的電機設備安全、可靠地運帶防雷保護的中繼器,使系統的安全運行得到了保行。證。MPI網絡的拓撲結構如圖1所示。1 多點網絡(NWI)監控系統的組成Sie me ns 公司S7系列PLC通常有MP」多點網絡與Profibus現場總線網絡兩種組網方式。Profibus現場總線的應用目前較為普遍,通用性較好,它由Profibus一DP, Profibus一FMS, Profibus一PA組成。Profibus - DP型用于分散外設間的數據傳輸,傳輸速率為9.6kbps一12Mbps,主要用于現場控制器與分散1/0之間的通信,可滿足交直流調速系統快速響應的時間要求,特別適合于加工自動化領域的應用;Profibus - FMS主要解決車間級通信問題,完成中等傳輸速度的循環或非循環數據交換任務,適用于紡織、樓宇自動化、可編程控制器、低壓開關等;Profibus - PA型采用了OSI模型的物理層和數據鏈路層,適用于過程自動化的總線類型。
Introduction to Xilinx Packaging Electronic packages are interconnectable housings for semiconductor devices. The major functions of the electronic packages are to provide electrical interconnections between the IC and the board and to efficiently remove heat generated by the device. Feature sizes are constantly shrinking, resulting in increased number of transistors being packed into the device. Today's submicron technology is also enabling large-scale functional integration and system-on-a-chip solutions. In order to keep pace with these new advancements in silicon technologies, semiconductor packages have also evolved to provide improved device functionality and performance. Feature size at the device level is driving package feature sizes down to the design rules of the early transistors. To meet these demands, electronic packages must be flexible to address high pin counts, reduced pitch and form factor requirements. At the same time,packages must be Reliable and cost effective.
為滿足無線網絡技術具有低功耗、節點體積小、網絡容量大、網絡傳輸可靠等技術要求,設計了一種以MSP430單片機和CC2420射頻收發器組成的無線傳感節點。通過分析其節點組成,提出了ZigBee技術中的幾種網絡拓撲形式,并研究了ZigBee路由算法。針對不同的傳輸要求形式選用不同的網絡拓撲形式可以盡大可能地減少系統成本。同時針對不同網絡選用正確的ZigBee路由算法有效地減少了網絡能量消耗,提高了系統的可靠性。應用試驗表明,采用ZigBee方式通信可以提高傳輸速率且覆蓋范圍大,與傳統的有線通信方式相比可以節約40%左右的成本。
Abstract:
To improve the proposed technical requirements such as low-ower, small nodes, large capacity and Reliable network transmission, wireless sensor nodes based on MSP430 MCU and CC2420 RF transceiver were designed. This paper provided network topology of ZigBee technology by analysing the component of the nodes and researched ZigBee routing algorithm. Aiming at different requirements of transmission mode to choose the different network topologies form can most likely reduce the system cost. And aiming at different network to choose the correct ZigBee routing algorithm can effectively reduced the network energy consumption and improved the reliability of the system. Results show that the communication which used ZigBee mode can improve the transmission rate, cover more area and reduce 40% cost compared with traditional wired communications mode.
同步技術是跳頻通信系統的關鍵技術之一,尤其是在快速跳頻通信系統中,常規跳頻通信通過同步字頭攜帶相關碼的方法來實現同步,但對于快跳頻來說,由于是一跳或者多跳傳輸一個調制符號,難以攜帶相關碼。對此引入雙跳頻圖案方法,提出了一種適用于快速跳頻通信系統的同步方案。采用短碼攜帶同步信息,克服了快速跳頻難以攜帶相關碼的困難。分析了同步性能,仿真結果表明該方案同步時間短、虛警概率低、捕獲概率高,同步性能可靠。
Abstract:
Synchronization is one of the key techniques to frequency-hopping communication system, especially in the fast frequency hopping communication system. In conventional frequency hopping communication systems, synchronization can be achieved by synchronization-head which can be used to carry the synchronization information, but for the fast frequency hopping, Because modulation symbol is transmitted by per hop or multi-hop, it is difficult to carry the correlation code. For the limitation of fast frequency hopping in carrying correlation code, a fast frequency-hopping synchronization scheme with two hopping patterns is proposed. The synchronization information is carried by short code, which overcomes the difficulty of correlation code transmission in fast frequency-hopping. The performance of the scheme is analyzed, and simulation results show that the scheme has the advantages of shorter synchronization time, lower probability of false alarm, higher probability of capture and more Reliable of synchronization.