【正文】
啟動仿真即可看到圖 2 中 上的仿真結(jié)果顯示為“ %RH”(存在微小的計算和數(shù)據(jù)轉(zhuǎn)換誤差) 該結(jié)果表明,系統(tǒng)的軟、硬件設(shè)計正確。 第七章 參考文獻(xiàn) [1]孫余凱 ,吳鳴 山 ,項綺明 .集成運算放大器實用電路識圖 [M].北京 :電子工業(yè)出版社 ,2021. [2]李贛平 ,邵惠鶴 .基于 ARM 的高精度智能流量變送器的設(shè)計 [J].電子技術(shù)應(yīng)用 ,2021,12. [3] 馮偉 ,白瑞林 ,李祥偉 .基于 的數(shù)字式觸摸屏驅(qū)動程序的開發(fā) [J].自動化儀表 , 2021,9. [4] 張洪潤 . 傳感器應(yīng)用設(shè)計 300 例(上冊) [M].北京 : 北京航空航天 大學(xué)出版社 , 2021. [5] 徐瑋 . C51 單片機高效入門 [M]. 北京 : 機械工業(yè)出版社 , 2021. [6] 師寶山 .基于 AT89S51 的多參數(shù)氣體檢測儀的研制 [J].微計算機 信息 , 2021, 7~1. [7]周堅單片機輕松入門 [M].北京 :北京航空航天大學(xué)出版社 , 2021. 。該設(shè)計采用集 成有 A/D 轉(zhuǎn)換模塊的高性能 LPC2131 芯片,省去了外加專用 A/D 采集芯片, 簡化了外圍電路設(shè)計。所示的仿真電路,再將由 Keil 軟件編譯并生成的系統(tǒng)驅(qū)動 程序 (“ *.hex 文 件 ”) 載 入 單 片 機 ,并 將圖 2 中 的 虛擬直流電壓信號發(fā)生器設(shè)為 45mV。 | //下降沿啟動轉(zhuǎn)換 DO =AD0DR。 ( 3)中斷。 ( 2) 時 鐘 產(chǎn) 生 。 第四章 系統(tǒng)的控制軟件設(shè)計 本 記錄儀的控制軟件設(shè)計采用模塊化思想 根據(jù)功能將系統(tǒng)控制軟件分為兩大模塊: ① ADC0832 的驅(qū)動程序模塊,控制電壓信號的采集;② 1602LCD 的驅(qū)動程序 模塊,顯示土壤濕度。該型單片機的優(yōu)點是 [3]: ①該單片機與 8051 系列單片機完全兼 容 ,容易使用,且成本十分低廉; ②內(nèi)部存儲器采用可反復(fù)擦寫的 EEPRROM,有利于反復(fù)修改程序; ③具有低耗能工作方式和能夠?qū)崿F(xiàn)掉電自動保護; ④具有較強的抗干擾性,大大提 高了抵御外界的電磁干擾能力,所以特別適合在條件相對惡劣的條件下工作。正常情況下, ADC0832 與單片機的接口應(yīng)為 4 條數(shù)據(jù)線,分別是 CS、 CLK、 DO、 DI。在第 3 個脈沖的下沉之前 DI 端則應(yīng)輸入兩位數(shù)據(jù)用于選擇通道功能。ADC0832 的工作。該傳感器的相對濕度 0%~100%RH 時,其對應(yīng)的輸出為 0~100mV[1]。 本文則詳細(xì)介紹了該檢測儀的測控電路和相關(guān)軟件流程。 關(guān)鍵詞: 土壤濕度; 檢測儀; 單片機; A/D 轉(zhuǎn)換; 仿真 中圖分類號: TP202 文獻(xiàn)標(biāo)識碼: A 第一章引言 農(nóng)業(yè)生產(chǎn)在我國的經(jīng)濟發(fā)展中具有重要地位,為農(nóng)業(yè)生產(chǎn)提供及時、 可靠的技術(shù)服務(wù)已成為氣象部門的重要職責(zé)之一 。| / / decrease along the startup conversion AD0DR。 The converted the integer part and the decimal part / / storage save A/D / / points don39。 And reliable work。 (2) Internal memory can be repeated CaXie by the EEPRROM, be helpful for repeatting modify the program。s cultural life and is good for mental and bodily health , but also can improve and purify air, improve health. Water is necessary for flower’s growth ,it influences the growth of flowers greatly. Too much water or too little, will affect the normal growth and the kind of flower is verious, Different flowers need different amount of water. The needful water, mostly from the soil, in order to control flowers moisture in the soil properly, using PRO F soil humidity sensor design an automatic watering the flowers system, it may, automatically set for flowers watering according to the humidity limit, in order to meet the need of imperative water. Section 2 position of the system The whole system consists of SCM, circuit of DAQ, keyboard input and digital display circuit, output controlling circuit etc. circuit of CAQ is made of 4 SRH and adc , SRH makes flower’s soil humidity convert into analog voltage output, adc makes the output of analog voltage convert into digital quantity and send to microcontroller. AT89S52 is adopted, the collectted value of soil humidity is pared with a preset limit soil moisture, and it makes corresponding judgement according to the pared results, to control the output controlling circuit’s action. Keyin is used to set the value of soil humidity’s limit, LED is used to display the current soil humidity’s value. Miniature soil detector signal processing system including soil humidity sensor Device, A/D acquisition circuit, SCM and micro LCD. Its work After cheng is: soil soil wet degrees preach sensor, will wet degrees letter sent to A/D adopt set electricity Road, the A/D conversion, ine data digital signal into SCM Processing, finally will processing results sent to micro LCD display. Section 3 the hardware design of system the circuit’ s working principle The hard thing the original reason system graph as figure 2 shows. This