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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
標簽：
看門狗電路
分
上傳時間：
2013-11-05
上傳用戶：685
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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
標簽：
單片機
中的應用
轉速測量
上傳時間：
2013-11-02
上傳用戶：源弋弋
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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.
標簽：
5channel
9516
PCA
I2C
上傳時間：
2013-11-21
上傳用戶：q123321
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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
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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.
標簽：
C-bus
SMBus
reset
port
上傳時間：
2014-01-18
上傳用戶：bs2005
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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
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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
標簽：
單片機
步進電機
開環
控制系統
上傳時間：
2013-10-13
上傳用戶：cicizoe
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基于單片機控制的二氧化碳濃度測試計:基于CDM4161二氧化碳氣體濃度測試模塊以及ATtiny26單片機,提出了一種二氧化碳濃度測試計的設計方案。該方案具有硬件電路簡單、成本低、可靠性高、測量準確等優點，具有較高的實用價值。 Abstract: Abstract：A desigh scheme of CO2 concentration meter based on CDM4161carbon dioxide concentration test module and ATtiny26micro-controller is presented in this paper.The design scheme features simple hardware circuit,low-cost,high reli-ability，accurate measurement and it has a high practical value.
標簽：
單片機控制
二氧化碳
測試
上傳時間：
2013-11-14
上傳用戶：zjwangyichao
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The μPSD32xx family, from ST, consists of Flash programmable system devices with a 8032 MicrocontrollerCore. Of these, the μPSD3234A and μPSD3254A are notable for having a complete implementationof the USB hardware directly on the chip, complying with the Universal Serial Bus Specification, Revision1.1.This application note describes a demonstration program that has been written for the DK3200 hardwaredemonstration kit (incorporating a μPSD3234A device). It gives the user an idea of how simple it is to workwith the device, using the HID class as a ready-made device driver for the USB connection.IN-APPLICATION-PROGRAMMING (IAP) AND IN-SYSTEM-PROGRAMMING (ISP)Since the μPSD contains two independent Flash memory arrays, the Micro Controller Unit (MCU) can executecode from one memory while erasing and programming the other. Product firmware updates in thefield can be reliably performed over any communication channel (such as CAN, Ethernet, UART, J1850)using this unique architecture. For In-Application-Programming (IAP), all code is updated through theMCU. The main advantage for the user is that the firmware can be updated remotely. The target applicationruns and takes care on its own program code and data memory.IAP is not the only method to program the firmware in μPSD devices. They can also be programmed usingIn-System-Programming (ISP). A IEEE1149.1-compliant JTAG interface is included on the μPSD. Withthis, the entire device can be rapidly programmed while soldered to the circuit board (Main Flash memory,Secondary Boot Flash memory, the PLD, and all configuration areas). This requires no MCU participation.The MCU is completely bypassed. So, the μPSD can be programmed or reprogrammed any time, anywhere, even when completely uncommitted.Both methods take place with the device in its normal hardware environment, soldered to a printed circuitboard. The IAP method cannot be used without previous use of ISP, because IAP utilizes a small amountof resident code to receive the service commands, and to perform the desired operations.
標簽：
Demonstration
3200
USB
for
上傳時間：
2014-02-27
上傳用戶：zhangzhenyu
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This application note shows how to write an Inter Integrated Circuit bus driver (I²C) for the Philips P90CL301micro-controller.It is not only an example of writing a driver, but it also includes a set of application interface software routines toquickly implement a complete I²C multi-master system application.For specific applications the user will have to make minimal changes in the driver program. Using the drivermeans linking modules to your application software and including a header-file into the application sourceprograms. A small example program of how to use the driver is listed.The driver supports i.a. polled or interrupt driven message handling, slave message transfers and multi-mastersystem applications. Furthermore, it is made suitable for use in conjunction with real time operating systems, likepSOS+.
標簽：
routines
driver
P90
301
上傳時間：
2013-11-23
上傳用戶：weixiao99
