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.
本文介紹了基于AT89C52 單片機的自動水溫控制系統的設計及實現過程。該系統具有實時顯示、溫度測量、溫度設定并能根據設定值對環境溫度進行調節實現控溫的目的以及達到上下限溫度報警功能，控制算法是基于數字PID 算法。關鍵詞 ：PID AT89C52 脈寬調制 實時
Abstract ： This article describes AT89C52 single-chip microcomputer-basedautomatic water temperature control system design and implementation process. Thesystem has real-time display, temperature measurement, temperature settings and theenvironment in accordance with the temperature settings adjusted to achieve thepurpose of temperature control and reach the upper and lower limits of temperaturealarm function, the control algorithm is based on the digital PID algorithm.Keyword: PID AT89C52 PWM real time
介紹了一種基于MSP430系列單片機和ADXL203加速度傳感器的數字式傾角儀，它不僅可以實現水平度檢測，而且可以測量00～3600范圍內的任意傾角，分辨率可達O．1。。此外，由于該傾角儀輸出為數字結果，因此它也可以與其他的數字設備結合起來，組合成一個功能更加強大的儀器。該數字傾角儀可廣泛應用于建筑、機械、道路、橋梁、石油、煤礦和地質勘探等各種需要測量重力參考系下傾角的場合。關鍵詞：MSP430F133單片機；力敏傳感器；ADXL203加速度計；角度測量
Abstract：This paper presents a new style digital inclinometer which is developed on the basis of the MSP430F133 MCU and the ADXL203 dual axis aeeelerometer．This inclinometer not only can test levelness，but also can measure any angle between 0。and 360。with an accuracy of 0．1 O．In addition，its output is a digital result，which makes it possible to integrate itself with other digital devices to form a more functional unit．This inclinometer can be widely used in any construction site，oil field，coal-mine or geologic survey and SO on where it will provide the working people with convenience to measure any angles．Key words：MSP430F133 MCU；force sensor；ADXL203 accelerometer；angle measurement
FEATURES400 MSPS internal clock speedIntegrated 10-bit DAC32-bit tuning wordPhase noise ≤ –120 dBc/Hz @ 1 kHz offset (DAC output)Excellent dynamic performance>75 dB SFDR @ 160 MHz (±100 kHz offset) AOUTSerial I/O control1.8 V power supplySoftware and hardware controlled power-down48-lead TQFP/EP packageSupport for 5 V input levels on most digital inputsPLL REFCLK multiplier (4× to 20×)Internal oscillator; can be driven by a single crystalPhase modulation capabilityMultichip synchronization
PICKIT™ 2 PROGRAMMER-TO-GO USER GUIDE
The PICkit 2 Programmer-To-Go functionality allows a PIC MCU memory image to be downloaded into the PICkit 2 unit for later programming into a specific PIC MCU. No software or PC is required to program devices once the PICkit 2 unit is set up for Programming-To-Go. A USB power source for the PICkit 2 is all that is needed.
Virtex-5, Spartan-DSP FPGAs Application Note
This application note demonstrates how efficient implementations of Digital Up Converters(DUC) and Digital Down Converters (DDC) can be done by leveraging the Xilinx DSP IPportfolio for increased productivity and reduced time to development. Step-by-step instruction is given on how to perform system-level trade off analysis and develop the most efficient FPGA implementation, thus allowing engineers a flexible, low-cost and low-power alternative to ASSP technologies.
This application note describes how to decode standard DTMF tones using the minimum number of external discrete components and a PIC. The two examples use a PIC which has an 8 bit timer and either a comparator or an ADC, although it can be modified for use on a PIC which has only digital I/O. The Appendices have example code for the 16C662 (with comparator) and 16F877 (using the ADC).
As the majority of the Digital Signal Processing is done in software, little is required in the way of external signal conditioning. Software techniques are used to model the individual elements of a DTMF Decoder IC.
The PCA9541 is a 2-to-1 I2C-bus master selector designed for high reliability dual masterI2C-bus applications where system operation is required, even when one master fails orthe controller card is removed for maintenance. The two masters (for example, primaryand back-up) are located on separate I2C-buses that connect to the same downstreamI2C-bus slave devices. I2C-bus commands are sent by either I2C-bus master and are usedto select one master at a time. Either master at any time can gain control of the slavedevices if the other master is disabled or removed from the system. The failed master isisolated from the system and will not affect communication between the on-line masterand the slave devices on the downstream I2C-bus.
The outputs of the PCA9518 are immediately available as soon as there is a voltage present on thesupply >~1V and behave as described above. The power-on reset of the PCA9518A keeps the outputsturned off during power-up and maintains the high impedance of the outputs throughout the power-upcycle. There is an additional built-in delay after power-up that allows the analog circuits to stabilize beforethe part is activated.
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.
