基于幅移鍵控技術ASK（Amplitude-Shift Keying），以C8051F340單片機作為監測終端控制器，C8051F330D單片機作為探測節點控制器，采用半雙工的通信方式，通過監控終端和探測節點的無線收發電路，實現數據的雙向無線傳輸。收發電路采用直徑為0.8 mm的漆包線自行繞制成圓形空心線圈天線，天線直徑為（3.4±0.3）cm。試驗表明，探測節點與監測終端的通信距離為24 cm，通過橋接方式，節點收發功率為102 mW時，節點間的通信距離可達20 cm。與傳統無線收發模塊相比，該無線收發電路在受體積、功耗、成本限制的場合有廣闊的應用前景。 Abstract: Based on ASK technology and with the C8051F340 and C8051F330D MCU as the controller， using half-duplex communication mode， this paper achieves bi-directional data transfer. Transceiver circuit constituted by enameled wire which diameter is 0.8mm and wound into a diameter （3.4±0.3） cm circular hollow coil antenna. Tests show that the communication distance between detection and monitoring of the terminal is 24cm，the distance is up to 20cm between two nodes when using the manner of bridging and the node transceiver power is 102mW. Compared with the conventional wireless transceiver modules， the circuit has wide application prospect in small size， low cost and low power consumption and other characteristics.
上傳時間： 2013-10-19
上傳用戶：xz85592677
為了在工業生產及過程控制中準確測量溫度，設計了一種基于低功耗MSP430單片機的數字溫度計。整個系統通過單片機MSP430F1121A控制DS18B20讀取溫度，采用數碼管顯示，溫度傳感器DS18B20與單片機之間通過串口進行數據傳輸。MSP430系列單片機具有超低功耗，且外圍的整合性高，DS18B20只需一個端口即可實現數據通信，連接方便。通過多次實驗證明，該系統的測試結果與實際環境溫度一致，除了具有接口電路簡單、測量精度高、誤差小、可靠性高等特點外，其低成本、低功耗的特點使其擁有更廣闊的應用前景。 Abstract: In order to obtain accurate measuring temperature in industrial production and process control， a digital thermometer based on MSP430 MCU is designed. The system uses MSP430F1121A MCU to control DS18B20， and gets the temperature data， which is displayed on the LED. The temperature sensor DS18B20 and MCU transmit data through serial communication. MSP430 series has ultra-low power and high integration， DS18B20 only needs one port to achieve data communication. Through many experimental results prove， this system is consistent with actual environment temperature. The system has characteristics of interface circuit simple， high measuring accuracy， minor error， high reliability， besides， the characteristics of low cost and low power make it having vaster application prospect.
上傳時間： 2013-10-16
上傳用戶：wettetw
The CAT93C46 is a 1 kb Serial EEPROM memory device which isconfigured as either 64 registers of 16 bits (ORG pin at VCC) or 128registers of 8 bits (ORG pin at GND). Each register can be written (orread) serially by using the DI (or DO) pin. The CAT93C46 features aself−timed internal write with auto−clear. On−chip Power−On Resetcircuit protects the internal logic against powering up in the wrongstate.
上傳時間： 2013-11-20
上傳用戶：ynzfm
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
上傳時間： 2013-11-05
上傳用戶：685
本文介紹了一種基于單片機的健身車轉速測量系統。該系統具有電路簡單、使用方便等特點。文中詳細介紹了該系統的工作原理,并且給出了它的硬件原理圖和軟件設計程序框圖。關鍵詞:轉速 單片機 測量ABSTRACT :This paper introduces a measuring system of the rotational velocity of exercise bike based on single - chip microcomputer . It has such advantages : simple circuit ,convenient use and so on. The work principle is presented in detail in this paper and the block diagram of hardware and program flow chart are giv2 en as well .KEYWORDS :Rotational velocity Single - chip microcomputer Measuring
上傳時間： 2013-11-02
上傳用戶：源弋弋
The PCA9516 is a BiCMOS integrated circuit intended forapplication in I2C and SMBus systems.While retaining all the operating modes and features of the I2Csystem, it permits extension of the I2C-bus by buffering both the data(SDA) and the clock (SCL) lines, thus enabling five buses of 400 pF.The I2C-bus capacitance limit of 400 pF restricts the number ofdevices and bus length. Using the PCA9516 enables the systemdesigner to divide the bus into five segments off of a hub where anysegment to segment transition sees only one repeater delay.
上傳時間： 2013-11-21
上傳用戶：q123321
The PCA9518 is a BiCMOS integrated circuit intended forapplication in I2C and SMBus systems.While retaining all the operating modes and features of the I2Csystem, it permits extension of the I2C-bus by buffering both thedata (SDA) and the clock (SCL) lines, thus enabling virtuallyunlimited buses of 400 pF.
標簽： Expandable 5channel 9518 PCA
上傳時間： 2013-10-23
上傳用戶：dumplin9
The PCA9557 is a silicon CMOS circuit which provides parallel input/output expansion for SMBus and I2C-bus applications. The PCA9557 consists of an 8-bit input port register, 8-bit output port register, and an I2C-bus/SMBus interface. It has low current consumption and a high-impedance open-drain output pin, IO0. The system master can enable the PCA9557’s I/O as either input or output by writing to the configuration register. The system master can also invert the PCA9557 inputs by writing to the active HIGH polarity inversion register. Finally, the system master can reset the PCA9557 in the event of a time-out by asserting a LOW in the reset input. The power-on reset puts the registers in their default state and initializes the I2C-bus/SMBus state machine. The RESET pin causes the same reset/initialization to occur without de-powering the part.
上傳時間： 2014-01-18
上傳用戶：bs2005
The MAX3243E device consists of three line drivers, five line receivers, and a dual charge-pump circuit with±15-kV ESD (HBM and IEC61000-4-2, Air-Gap Discharge) and ±8-kV ESD (IEC61000-4-2, Contact Discharge)protection on serial-port connection pins. The device meets the requirements of TIA/EIA-232-F and provides theelectrical interface between an asynchronous communication controller and the serial-port connector. Thiscombination of drivers and receivers matches that needed for the typical serial port used in an IBM PC/AT, orcompatible. The charge pump and four small external capacitors allow operation from a single 3-V to 5.5-Vsupply. In addition, the device includes an always-active noninverting output (ROUT2B), which allowsapplications using the ring indicator to transmit data while the device is powered down. The device operates atdata signaling rates up to 250 kbit/s and a maximum of 30-V/ms driver output slew rate.
標簽： MULTICHANNEL 5.5 TO RS
上傳時間： 2013-10-19
上傳用戶：ddddddd
基于單片機的步進電機開環控制系統:通過ATMEL89C51單片機對步進電機進行控制,主要介紹了步進電機控制器、驅動電路和LED顯示電路的設計,實現了步進電機的開環控制。在步進電機控制器的設計中,重點闡述了脈沖產生電路以及對速度的控制。該系統具有成本低、控制方便的特點。關鍵詞: 單片機; 步進電機; 開環控制 Abstract: The design using ATMEL89C51 single chip to control the step2motor with its controller, driving circuit and LED disp lay circuit to realize step motor open2loop controlwere introduced. For the controller in this design,the circuit to p roduce pulse and the speed controlwere expatiated emphatically. This system possesses features of lower cost, easier control.Key words: single ch ip; step2motor; open2loop con trol
上傳時間： 2013-10-13
上傳用戶：cicizoe
