【正文】
幅。 第四步:設(shè)置回波放大器的所得來(lái)規(guī) 格輸出,假定是 3伏。其部分源程序如下: RECEIVE0: PUSH PSW PUSH ACC CLR EX0 ; 關(guān)外部中斷 0 MOV R7, TH0 ; 讀取時(shí)間值 MOV R6, TL0 CLR C MOV A, R6 SUBB A, 0BBH; 計(jì)算時(shí)間差 MOV 31H, A ; 存儲(chǔ)結(jié)果 MOV A, R7 SUBB A, 3CH MOV 30H, A SETB EX0 ; 開(kāi)外部中斷 0 POP ACC POP PSW RETI 對(duì)于一個(gè)平坦的目標(biāo),距離測(cè)量包括兩個(gè)階段 :粗糙的測(cè)量和精細(xì)測(cè)量。 IC2是帶有鎖 定環(huán)的音頻譯碼集成塊 LM567,內(nèi)部的壓控振蕩器 的中心頻率f0=1/,電容 C4決定其鎖定帶寬。 圖 1 電路原理圖 40kHz 脈沖的產(chǎn)生與超聲波發(fā)射 測(cè)距系統(tǒng)中的超聲波傳感器采用 UCM40的壓電陶瓷傳感器,它的工作電壓是 40kHz的脈沖信號(hào),這由單片機(jī)執(zhí)行下面程序來(lái)產(chǎn)生。強(qiáng)度較強(qiáng)的脈沖會(huì)比強(qiáng)度較弱的脈沖超過(guò)界限的時(shí)間早點(diǎn),因此我們會(huì)認(rèn)為強(qiáng)度較強(qiáng)的脈沖屬于較近的物體。這個(gè)界限恰恰選于噪音水平之上,然而脈沖到達(dá)時(shí)間被定義為脈沖信號(hào)剛好超過(guò)界限的第一時(shí)刻。超聲波發(fā)生器內(nèi)部結(jié)構(gòu),它有兩個(gè)壓電晶片和一個(gè)共振板。而設(shè)計(jì)研制箱涵排水疏通移動(dòng)機(jī)器人的自動(dòng)控制系統(tǒng),保證機(jī)器人在箱涵中自由排污疏通,是箱涵排污疏通機(jī)器人的設(shè)計(jì)研制的核心部分。 關(guān)鍵詞:超聲波,測(cè)距儀,單片機(jī) 前言 隨著科技的發(fā)展,人們生活水平的提高,城市發(fā)展建設(shè)加快,城市給排水系統(tǒng)也有較大發(fā)展,其狀況不斷改善。 storage results MOV A, R7 SUBB A, 3CH MOV 30H, A SETB EX0。 left Ranging entrance circuit interrupt service routine Ajmp Return The calculation of ultrasonic propagation time When you start firing at the same time start the singlechip circuitry within the timer T0, the use of timer counting function records the time and the launch of ultrasonic reflected wave received time. When you receive the ultrasonic reflected wave, the receiver circuit outputs a negative jump in the end of INT0 or INT1 interrupt request generates a signal, singlechip microputer in response to external interrupt request, the implementation of the external interrupt service subroutine, read the time difference, calculating the distance . Some of its source code is as follows: RECEIVE0: PUSH PSW PUSH ACC CLR EX0。 pin to 0, ranging from right to interrupt service routine circuit jnb , left。 nop。s starting point to the moment when it surpasses the threshold changes with the intensity of the echo. As a consequence, a considerable error may occur Even two echoes with different intensities arriving exactly at the same time will surpass the threshold at different moments. principle of ultrasonic distance measurement Ultrasonic transmitter in a direction to launch ultrasound, in the moment to launch the beginning of time at the same time, the spread of ultrasound in the air, obstacles on his way to return immediately, the ultrasonic reflected wave received by the receiver immediately stop the clock. Ultrasound in the air as the p