摘要：介紹一種基于單片機(jī)AT89C51和V/F轉(zhuǎn)換器LM331的壓力數(shù)據(jù)采集系統(tǒng)，該系統(tǒng)以AT89C51單片機(jī)為核心，實(shí)時(shí)測(cè)量由壓力傳感器MPXV5004G檢測(cè)的壓力。與傳統(tǒng)電路設(shè)計(jì)相比較，其外部硬件電路少，結(jié)構(gòu)簡(jiǎn)單，無(wú)較大的時(shí)延。只要對(duì)其功能進(jìn)行擴(kuò)展，能夠?qū)崿F(xiàn)相應(yīng)控制。關(guān)鍵詞：壓力傳感器，V/F轉(zhuǎn)換器，單片機(jī)，頻率測(cè)量，LM331
上傳時(shí)間： 2013-10-09
上傳用戶：atdawn
我們?cè)谧鲆粋€(gè)單片機(jī)系統(tǒng)時(shí)，常常會(huì)遇到這樣那樣的數(shù)據(jù)采集，在這些被采集的數(shù)據(jù)中，大部分可以通過(guò)我們的I/O口擴(kuò)展接口電路直接得到，由于51單片機(jī)大部分不帶AD轉(zhuǎn)換器，所以模擬量的采集就必須靠A/D或V/F實(shí)現(xiàn)。下現(xiàn)我們就來(lái)了解一下AD0809與51單片機(jī)的接口及其程序設(shè)計(jì)。
標(biāo)簽： 0809 AD 51單片機(jī) 中的應(yīng)用
上傳時(shí)間： 2013-10-19
上傳用戶：gaome
AVR單片機(jī)技術(shù)原理 AVR單片機(jī)介紹 單片機(jī)又稱(chēng)單片微控制器，它是把一個(gè)計(jì)算機(jī)系統(tǒng)集成到一個(gè)芯片上，概括的講：一塊芯片就成了一臺(tái)計(jì)算機(jī)。單片機(jī)技術(shù)是計(jì)算機(jī)技術(shù)的一個(gè)分支,是簡(jiǎn)易機(jī)器人的核心元件。 1997年,由ATMEL公司挪威設(shè)計(jì)中心的A先生與V先生利用ATMEL公司的Flash新技術(shù), 共同研發(fā)出RISC精簡(jiǎn)指令集的高速8位單片機(jī)，簡(jiǎn)稱(chēng)AVR。[編輯本段]AVR單片機(jī)的優(yōu)勢(shì)特征 單片機(jī)已廣泛地應(yīng)用于軍事、工業(yè)、家用電器、智能玩具、便攜式智能儀表和機(jī)器人制作等領(lǐng)域，使產(chǎn)品功能、精度和質(zhì)量大幅度提升，且電路簡(jiǎn)單，故障率低，可靠性高，成本低廉。單片機(jī)種類(lèi)很多，在簡(jiǎn)易機(jī)器人制作和創(chuàng)新中，為什么選用AVR單片機(jī)呢？ 一、簡(jiǎn)便易學(xué)，費(fèi)用低廉 首先，對(duì)于非專(zhuān)業(yè)人員來(lái)說(shuō)，選擇AVR單片機(jī)的最主要原因，是進(jìn)入AVR單片機(jī)開(kāi)發(fā)的門(mén)檻非常低，只要會(huì)操作電腦就可以學(xué)習(xí)AVR單片機(jī)的開(kāi)發(fā)。單片機(jī)初學(xué)者只需一條ISP下載線，把編輯、調(diào)試通過(guò)的軟件程序直接在線寫(xiě)入AVR單片機(jī)，即可以開(kāi)發(fā)AVR單片機(jī)系列中的各種封裝的器件。AVR單片機(jī)因此在業(yè)界號(hào)稱(chēng)“一線打天下”。 其次，AVR單片機(jī)便于升級(jí)。AVR程序?qū)懭胧侵苯釉陔娐钒迳线M(jìn)行程序修改、燒錄等操作，這樣便于產(chǎn)品升級(jí)。 再次，AVR單片機(jī)費(fèi)用低廉。學(xué)習(xí)AVR單片機(jī)可使用ISP在線下載編程方式(即把PC機(jī)上編譯好的程序?qū)懙絾纹瑱C(jī)的程序存儲(chǔ)器中)，不需購(gòu)買(mǎi)仿真器、編程器、擦抹器和芯片適配器等，即可進(jìn)行所有AVR單片機(jī)的開(kāi)發(fā)應(yīng)用，這可節(jié)省很多開(kāi)發(fā)費(fèi)用。程序存儲(chǔ)器擦寫(xiě)可達(dá)10000次以上，不會(huì)產(chǎn)生報(bào)廢品。 二、高速、低耗、保密 首先，AVR單片機(jī)是高速嵌入式單片機(jī)： 1、AVR單片機(jī)具有預(yù)取指令功能，即在執(zhí)行一條指令時(shí)，預(yù)先把下一條指令取進(jìn)來(lái)，使得指令可以在一個(gè)時(shí)鐘周期內(nèi)執(zhí)行。 2、多累加器型，數(shù)據(jù)處理速度快。AVR單片機(jī)具有32個(gè)通用工作寄存器，相當(dāng)于有32條立交橋，可以快速通行。 3、中斷響應(yīng)速度快。AVR單片機(jī)有多個(gè)固定中斷向量入口地址，可快速響應(yīng)中斷。 其次，AVR單片機(jī)耗能低。對(duì)于典型功耗情況，WDT關(guān)閉時(shí)為100nA，更適用于電池供電的應(yīng)用設(shè)備。有的器件最低1.8 V即可工作。 再次，AVR單片機(jī)保密性能好。它具有不可破解的位加密鎖Lock Bit技術(shù)，保密位單元深藏于芯片內(nèi)部，無(wú)法用電子顯微鏡看到。 三、I/O口功能強(qiáng),具有A/D轉(zhuǎn)換等電路 1. AVR單片機(jī)的I/O口是真正的I/O口，能正確反映I/O口輸入/輸出的真實(shí)情況。工業(yè)級(jí)產(chǎn)品，具有大電流(灌電流)10～40 mA,可直接驅(qū)動(dòng)可控硅SCR或繼電器，節(jié)省了外圍驅(qū)動(dòng)器件。 2. AVR單片機(jī)內(nèi)帶模擬比較器，I/O口可用作A/D轉(zhuǎn)換，可組成廉價(jià)的A/D轉(zhuǎn)換器。ATmega48/8/16等器件具有8路10位A/D。 3. 部分AVR單片機(jī)可組成零外設(shè)元件單片機(jī)系統(tǒng)，使該類(lèi)單片機(jī)無(wú)外加元器件即可工作，簡(jiǎn)單方便，成本又低。 4. AVR單片機(jī)可重設(shè)啟動(dòng)復(fù)位,以提高單片機(jī)工作的可靠性。有看門(mén)狗定時(shí)器實(shí)行安全保護(hù),可防止程序走亂(飛),提高了產(chǎn)品的抗干擾能力。 四、有功能強(qiáng)大的定時(shí)器/計(jì)數(shù)器及通訊接口 定時(shí)/計(jì)數(shù)器T/C有8位和16位,可用作比較器。計(jì)數(shù)器外部中斷和PWM(也可用作D/A)用于控制輸出，某些型號(hào)的AVR單片機(jī)有3～4個(gè)PWM，是作電機(jī)無(wú)級(jí)調(diào)速的理想器件。 AVR單片機(jī)有串行異步通訊UART接口,不占用定時(shí)器和SPI同步傳輸功能,因其具有高速特性，故可以工作在一般標(biāo)準(zhǔn)整數(shù)頻率下,而波特率可達(dá)576K。
標(biāo)簽： AVR 單片機(jī)技術(shù)
上傳時(shí)間： 2013-10-18
上傳用戶：二十八號(hào)
I/O 型單片機(jī)使用手冊(cè) 目錄 間接尋址寄存器 – IAR, IAR0, IAR1 .............................................35間接尋址指針 – MP, MP0, MP1 ......................................................35存儲(chǔ)區(qū)指針 – BP .........................................................................36累加器 – ACC...................................................................................37程序計(jì)數(shù)器低字節(jié)寄存器 – PCL....................................................37表格寄存器 – TBLP,TBHP,TBLH....................................................37看門(mén)狗定時(shí)寄存器 – WDTS............................................................38狀態(tài)寄存器 – STATUS.....................................................................38中斷控制寄存器 – INTC,INTC0,INTC1 .........................................39定時(shí)/計(jì)數(shù)寄存器...............................................................................39輸入/輸出端口和控制寄存器...........................................................40UART 寄存器 .USR,UCR1,UCR2,TXR/RXR,BRG.......................40輸入/輸出端口..........................................................................................41上拉電阻............................................................................................41PA 口的喚醒......................................................................................41輸入/輸出端口控制寄存器...............................................................41引腳共享功能....................................................................................42編程注意事項(xiàng)....................................................................................45定時(shí)/計(jì)數(shù)器..............................................................................................46配置定時(shí)/計(jì)數(shù)器輸入時(shí)鐘源...........................................................47定時(shí)/計(jì)數(shù)寄存器 – TMR, TMR0,TMR0L/TMR0H,TMR1L/TMR1H,TMR2.....................................................................49定時(shí)/計(jì)數(shù)控制寄存器 – TMRC,TMR0C,TMR1C,TMR2C............50定時(shí)器模式........................................................................................53事件計(jì)數(shù)器模式................................................................................53脈沖寬度測(cè)量模式............................................................................54可編程分頻器(PFD)和蜂鳴器的應(yīng)用..............................................55預(yù)分頻器(Prescaler)...........................................................................56輸入/輸出接口...................................................................................56編程注意事項(xiàng)....................................................................................57定時(shí)/計(jì)數(shù)器應(yīng)用范例.......................................................................57中斷............................................................................................................59中斷寄存器........................................................................................59中斷優(yōu)先權(quán)........................................................................................62外部中斷............................................................................................63定時(shí)/計(jì)數(shù)器中斷...............................................................................64UART 中斷........................................................................................64編程注意事項(xiàng)....................................................................................65復(fù)位和初始化............................................................................................66復(fù)位....................................................................................................66目錄iii異步串行口——UART............................................................................74UART 特性..........................................................................................74UART 外部引腳..................................................................................74數(shù)據(jù)發(fā)送.............................................................................................75UART 狀態(tài)控制寄存器......................................................................75波特率發(fā)生器.....................................................................................79UART 設(shè)置與控制..............................................................................81UART 發(fā)送器......................................................................................83UART 接收器......................................................................................84接收錯(cuò)誤處理.....................................................................................85接收中斷圖解.....................................................................................86地址檢測(cè)模式.....................................................................................86暫停模式下的UART 功能.................................................................87UART 應(yīng)用范例.................................................................................87振蕩器........................................................................................................89系統(tǒng)時(shí)鐘配置....................................................................................89系統(tǒng)晶體/陶瓷振蕩器.......................................................................89系統(tǒng)電阻電容振蕩器........................................................................90內(nèi)部系統(tǒng)電阻電容振蕩器................................................................90RTC 振蕩器........................................................................................91看門(mén)狗定時(shí)振蕩器............................................................................91暫停和喚醒................................................................................................92暫停.....................................................................................................92進(jìn)入暫停.............................................................................................92靜態(tài)電流.............................................................................................92喚醒....................................................................................................92看門(mén)狗定時(shí)器............................................................................................94掩膜選項(xiàng)....................................................................................................96應(yīng)用電路....................................................................................................97第二部份 程序語(yǔ)言.....................................................................99第二章 指令集介紹.................................................................................101指令集......................................................................................................101指令周期..........................................................................................101數(shù)據(jù)的傳送......................................................................................101算術(shù)運(yùn)算..........................................................................................102邏輯和移位運(yùn)算..............................................................................102分支和控制的轉(zhuǎn)換..........................................................................102位運(yùn)算..............................................................................................102查表運(yùn)算..........................................................................................103其它運(yùn)算..........................................................................................103指令設(shè)定一覽表......................................................................................104慣例..................................................................................................104I/O 型單片機(jī)使用手冊(cè)iv第三章 指令定義.....................................................................................107第四章 匯編語(yǔ)言和編譯器.....................................................................121常用符號(hào)..................................................................................................121語(yǔ)句語(yǔ)法..................................................................................................122名稱(chēng)..................................................................................................122操作項(xiàng)..............................................................................................122操作數(shù)項(xiàng)..........................................................................................122注解..................................................................................................122編譯偽指令..............................................................................................123條件編譯偽指令..............................................................................123文件控制偽指令..............................................................................124程序偽指令......................................................................................126數(shù)據(jù)定義偽指令..............................................................................130宏指令..............................................................................................132匯編語(yǔ)言指令..........................................................................................136名稱(chēng)..................................................................................................136助記符..............................................................................................136操作數(shù)、運(yùn)算子和表達(dá)式..............................................................136其它..........................................................................................................139前置引用..........................................................................................139局部標(biāo)號(hào)..........................................................................................139匯編語(yǔ)言保留字..............................................................................140編譯器選項(xiàng)..............................................................................................141編譯列表文件格式..................................................................................141源程序列表......................................................................................141編譯總結(jié)..........................................................................................142其它..................................................................................................142第三部份 開(kāi)發(fā)工具................................................................... 145第五章 單片機(jī)開(kāi)發(fā)工具.........................................................................147HT-IDE 集成開(kāi)發(fā)環(huán)境............................................................................147盛群?jiǎn)纹瑱C(jī)仿真器(HT-ICE) ..................................................................149HT-ICE 接口卡.................................................................................149OTP 燒寫(xiě)器.....................................................................................149OTP 適配卡.....................................................................................149系統(tǒng)配置..................................................................................................150HT-ICE 接口卡設(shè)置........................................................................151安裝..........................................................................................................153系統(tǒng)要求..........................................................................................153硬件安裝..........................................................................................153軟件安裝..........................................................................................154目錄v第六章 快速開(kāi)始.....................................................................................159步驟一：建立一個(gè)新項(xiàng)目..............................................................159步驟二：將源程序文件加到項(xiàng)目中..............................................159步驟三：編譯項(xiàng)目..........................................................................159步驟四：燒寫(xiě)OTP 單片機(jī).............................................................160步驟五：傳送程序與掩膜選項(xiàng)單至Holtek ..................................160附錄............................................................................................... 161附錄A 特性曲線圖...................................................................................163附錄B 封裝信息.......................................................................................173
上傳時(shí)間： 2013-10-18
上傳用戶：blacklee
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.
上傳時(shí)間： 2013-11-17
上傳用戶：vodssv
Nios 的用戶定義接口邏輯實(shí)例 有許多人問(wèn)我使用 Nios 的用戶定義接口邏輯怎么用，想了幾天決定設(shè)計(jì)一個(gè)實(shí)例來(lái)說(shuō)明。該例為一個(gè)使用 user to interface logic 設(shè)計(jì)的 PWM 實(shí)例，其中包括三個(gè)文件： plus32.v 是一個(gè)為 32bit nios 設(shè)計(jì)的 pwm 實(shí)例。 plus16.v 是一個(gè)為 16bit nios 設(shè)計(jì)的 pwm 實(shí)例。 test.s 是一個(gè)使用中斷調(diào)用 pwm 的匯編語(yǔ)言測(cè)試程序。以上模塊和程序均調(diào)試通過(guò)，并可穩(wěn)定工作。這里讓大家參考是使大家通過(guò)該例來(lái)真正理解 user to interface logic 設(shè)計(jì)方法，和nios 中通過(guò)匯編調(diào)用中斷的方法，所以超值喔。另外熱烈歡迎大家的指導(dǎo)。 注：在設(shè)計(jì) Nios 時(shí)，將你調(diào)用的 user to interface logic 插件重命名為 plus_0，這樣我的 test.s 可不作任何改動(dòng)，你就可用示波器通過(guò) nios 的 plus 管腳觀察到一個(gè)要求的輸出。
上傳時(shí)間： 2013-11-15
上傳用戶：cc1915
linux 中斷和設(shè)備驅(qū)動(dòng) 本章介紹L i n u x內(nèi)核是如何維護(hù)它支持的文件系統(tǒng)中的文件的，我們先介紹 V F S ( Vi r t u a lFile System，虛擬文件系統(tǒng))，再解釋一下L i n u x內(nèi)核的真實(shí)文件系統(tǒng)是如何得到支持的。L i n u x的一個(gè)最重要特點(diǎn)就是它支持許多不同的文件系統(tǒng)。這使 L i n u x非常靈活，能夠與許多其他的操作系統(tǒng)共存。在寫(xiě)這本書(shū)的時(shí)候， L i n u x共支持1 5種文件系統(tǒng)： e x t、 e x t 2、x i a、 m i n i x、 u m s d o s、 msdos 、v f a t、 p r o c、 s m b、 n c p、 i s o 9 6 6 0、 s y s v、 h p f s、 a ffs 和u f s。無(wú)疑隨著時(shí)間的推移，L i n u x支持的文件系統(tǒng)數(shù)還會(huì)增加。
標(biāo)簽： linux 中斷 設(shè)備驅(qū)動(dòng)
上傳時(shí)間： 2013-11-13
上傳用戶：zxh122
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.
標(biāo)簽： interru SMBus power 9534
上傳時(shí)間： 2013-10-10
上傳用戶：inwins
The PCA9535 and PCA9535C are 24-pin CMOS devices that provide 16 bits of GeneralPurpose parallel Input/Output (GPIO) expansion for I2C-bus/SMBus applications and wasdeveloped to enhance the NXP Semiconductors family of I2C-bus I/O expanders. Theimprovements include higher drive capability, 5 V I/O tolerance, lower supply current,individual I/O configuration, and smaller packaging. I/O expanders provide a simplesolution when additional I/O is needed for ACPI power switches, sensors, push buttons,LEDs, fans, etc.
上傳時(shí)間： 2013-10-21
上傳用戶：愛(ài)死愛(ài)死
The PCA9517 is a CMOS integrated circuit that provides level shifting between lowvoltage (down to 0.9 V) and higher voltage (2.7 V to 5.5 V) I2C-bus or SMBus applications.While retaining all the operating modes and features of the I2C-bus system during thelevel shifts, it also permits extension of the I2C-bus by providing bidirectional buffering forboth the data (SDA) and the clock (SCL) lines, thus enabling two buses of 400 pF. Usingthe PCA9517 enables the system designer to isolate two halves of a bus for both voltageand capacitance. The SDA and SCL pins are over voltage tolerant and arehigh-impedance when the PCA9517 is unpowered.
標(biāo)簽： translating Level 9517 PCA
上傳時(shí)間： 2013-12-25
上傳用戶：wsf950131
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