CDMA has been quite successful as a second-generation cellular system,Having achieved widespread use in particular in North America and Korea by the turn of the twenty-first century.
Pattern-MAC (PMAC) protocol, instead of Having fixed sleepwakeups,
the sleep-wakeup schedules of the sensor nodes are
adaptively determined. The schedules are decided based on a
node’s own traffic and that of its neighbors.
Control systems are becoming increasingly dependent on digital processing and so require sensors able to provide direct digital inputs. Sensors based on time measurement, Having outputs based on a frequency or phase, have an advantage over conventional analogue sensors in that their outputs can be measured directly in digital systems by pulse counting.
Designing Boards with Atmel AT89C51,AT89C52, AT89C1051, and AT89C2051 for Writing Flash at In-Circuit Test.
Recent improvements in chips and testers have made it possible for the tester to begin taking over the role tradi-tionally assigned to the PROM program-mer. Instead of Having a PROM pro- grammer write nonvolatile memories before assembling the board, the in-cir- cuit tester writes them during in-circuit testing operations. Many Teradyne Z18- series testers are now in use loading code into nonvolatile memories, micro- controllers and in-circuit programmable logic devices. The purpose of this note is to explain how the Z18 approaches the writing task for Atmel AT89C series IC’s, so that designers of boards using these chips can get the best results.
為了在工業(yè)生產(chǎn)及過程控制中準(zhǔn)確測量溫度，設(shè)計了一種基于低功耗MSP430單片機(jī)的數(shù)字溫度計。整個系統(tǒng)通過單片機(jī)MSP430F1121A控制DS18B20讀取溫度，采用數(shù)碼管顯示，溫度傳感器DS18B20與單片機(jī)之間通過串口進(jìn)行數(shù)據(jù)傳輸。MSP430系列單片機(jī)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(xiàn)數(shù)據(jù)通信，連接方便。通過多次實驗證明，該系統(tǒng)的測試結(jié)果與實際環(huán)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(yīng)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.
針對當(dāng)前安檢力學(xué)試驗機(jī)所能完成的試驗種類單一、自動化程度低等問題，提出一種以ATmega128單片機(jī)為核心控制器的安檢力學(xué)試驗機(jī)的設(shè)計。詳細(xì)闡述了該安檢力學(xué)試驗機(jī)各個組成部分的設(shè)計原理和方案，并且給出了各部分的軟件設(shè)計思想和操作流程。經(jīng)過大量測試試驗表明：設(shè)計的安檢力學(xué)試驗機(jī)可以完成多達(dá)十余種的力學(xué)安檢試驗，完全符合相關(guān)國家標(biāo)準(zhǔn)，并且具有數(shù)據(jù)采集精度高、傳輸速度快、操作安全簡便等特點，實現(xiàn)了安檢設(shè)備的多功能化、數(shù)字化和自動化。
Abstract:
Currently， many mechanical security testing machines have only one function. The degree of automation of them is low. To solve those problems， a new kind of mechanical security testing machine， using ATmega128 micro-controller as its core controller， has been advanced. It describes the components of the machine. The principles and the scheme in the designing processes are presented in detail， and the software architecture and the operation processes of each part are given. After Having done many testing， we have reached the following conclusions: the mechanical security testing machine presented can do over ten mechanical security tests complying with related national standards. It has high data acquisition accuracy and high transmission speed. The operation of the machine is simple and safe. In general， this machine is a multi-functional， highly automatic， digitalized security testing device.
The PCA9670 provides general purpose remote I/O expansion for most microcontrollerfamilies via the two-line bidirectional bus (I2C-bus) and is a part of the Fast-mode Plusfamily.The PCA9670 is a drop-in upgrade for the PCF8574 providing higher Fast-mode Plus(Fm+) I2C-bus speeds (1 MHz versus 400 kHz) so that the output can support PWMdimming of LEDs, higher I2C-bus drive (30 mA versus 3 mA) so that many more devicescan be on the bus without the need for bus buffers, higher total package sink capacity(200 mA versus 100 mA) that supports Having all 25 mA LEDs on at the same time andmore device addresses (64 versus 8) are available to allow many more devices on the buswithout address conflicts.
The PCA9671 provides general purpose remote I/O expansion for most microcontrollerfamilies via the two-line bidirectional bus (I2C-bus) and is a part of the Fast-mode Plus(Fm+) family.The PCA9671 is a drop in upgrade for the PCF8575 providing higher I2C-bus speeds(1 MHz versus 400 kHz) so that the output can support PWM dimming of LEDs, higherI2C-bus drive (30 mA versus 3 mA) so that many more devices can be on the bus withoutthe need for bus buffers, higher total package sink capacity (400 mA versus 100 mA) thatsupports Having all 25 mA LEDs on at the same time and more device addresses (64versus 8) to allow many more devices on the bus without address conflicts.
