單片機作為一種微型計算機，其內(nèi)部具有一定的存儲單元（8031除外），但由于其內(nèi)部存儲單元及端口有限，很多情況下難以滿足實際需求。為此介紹一種新的擴展方法，將數(shù)據(jù)線與地址線合并使用，通過軟件控制的方法實現(xiàn)數(shù)據(jù)線與地址線功能的分時轉(zhuǎn)換，數(shù)據(jù)線不僅用于傳送數(shù)據(jù)信號，還可作為地址線、控制線，用于傳送地址信號和控制信號，從而實現(xiàn)單片機與存儲器件的有效連接。以單片機片外256KB數(shù)據(jù)存儲空間的擴展為例，通過該擴展方法，僅用10個I/O端口便可實現(xiàn)，與傳統(tǒng)的擴展方法相比，可節(jié)約8個I/O端口。
Abstract:
As a micro-computer,the SCM internal memory has a certain units(except8031),but because of its internal storage units and the ports are limited,in many cases it can not meet the actual demand.So we introduced a new extension method,the data line and address lines combined through software-controlled approach to realize the time-conversion functions of data lines and address lines,so the data lines not only transmited data signals,but also served as address lines and control lines to transmit address signals and control signals,in order to achieve an effective connection of microcontroller and memory chips.Take microcontroller chip with256KB of data storage space Expansion as example,through this extension method,with only10I/O ports it was achieved,compared with the traditional extension methods,this method saves8I/O ports.
為提高溫度測量效率，降低系統(tǒng)的成本，擴展傳輸距離，設(shè)計出一種新型溫度采集系統(tǒng)。單片機通過控制具有單總線方式的溫度傳感器DS18B20實現(xiàn)對溫度的測量，同時單片機通過控制具有單總線方式300～450MHz頻率范圍內(nèi)的MAX7044與MAX7033無線發(fā)射與接收芯片實現(xiàn)溫度數(shù)據(jù)的無線傳輸。與傳統(tǒng)溫度采集系統(tǒng)相比，該系統(tǒng)利用單總線方式連接，采用無線傳輸方式實現(xiàn)遠距離通信，易于系統(tǒng)的集成與擴展。實驗結(jié)果表明，該系統(tǒng)結(jié)構(gòu)簡單、方便移植，能夠同時實現(xiàn)多達上百點溫度的測量與500m范圍的傳輸。
Abstract:
To improve the temperature measurement efficiency and reduce system cost,Expansion of transmission distance,a new type of temperature acquisition system is designed.Microcontroller controlled temperature sensor DS18B20which has a single-bus achieves temperature measurement,while microcontroller by controlled the MAX7044and MAX7033chip with a single-bus and having300~450MHz radiofrequency to achieve the wireless transmission of temperature data.Compared with conventional temperature acquisition system,the system uses single-bus connected,and uses wireless transmission means to achieve long-distance communications,easy-to-system integration and Expansion.The experimental results show that the system is simple,convenient transplantation,and can be implemented in as many as a hundred-point temperature measure-ment and the transmission range of500meters.
闡述了一個由上位PC機和AT89C52下位單片機組成的主從分布式溫度巡回檢測系統(tǒng)。主從機采用RS-485 串行通訊標準進行通信，可在下位單片機實現(xiàn)基本的溫度數(shù)據(jù)巡回檢測基礎(chǔ)上，由上位PC機實現(xiàn)綜合處理功能或擴展為遠程操作。整個系統(tǒng)具有巡檢速度快，擴展性好的特點。
Abstract:
In this paper,a top PC and AT89C52 under-bit microcontrollers from the main component of the tour distributed temperature detection system is presented. Master and slave can use RS-485 serial communication standards for communications.Based on next-bit machine for basic goods temperature detected data Tour, the top can achieve the integrated treatment of PC functions or for the Expansion of long-distance operation. The entire inspection system is fast, Expansion.
The PCA9674/74A provide general purpose remote I/O Expansion for most
microcontroller families via the two-line bidirectional bus (I2C-bus) and is a part of the
Fast-mode Plus (Fm+) family.
The PCA9536 is an 8-pin CMOS device that provides 4 bits of General Purpose parallel
Input/Output (GPIO) Expansion for I2C-bus/SMBus applications and was developed to
enhance the NXP Semiconductors family of I2C-bus I/O expanders. I/O expanders provide
a simple solution when additional I/O is needed for ACPI power switches, sensors,
push buttons, LEDs, fans, etc.
The PCA9534 is a 16-pin CMOS device that provide 8 bits of General Purpose parallel
Input/Output (GPIO) Expansion for I2C-bus/SMBus applications and was developed to
enhance the NXP Semiconductors family of I2C-bus I/O expanders. The improvements
include higher drive capability, 5 V I/O tolerance, lower supply current, individual I/O
configuration, 400 kHz clock frequency, and smaller packaging. I/O expanders provide a
simple solution when additional I/O is needed for ACPI power switches, sensors,
push buttons, LEDs, fans, etc.
