傳統(tong)方(fang)法(fa)采用單(dan)片機控(kong)制步(bu)(bu)進(jin)電機，但由于單(dan)片機的系統(tong)資源、運(yun)算速度(du)和存儲空間的限制，每個單(dan)片機控(kong)制的步(bu)(bu)進(jin)電機的數量較(jiao)少，而每臺電腦燈往往需要(yao)很多步(bu)(bu)進(jin)電機。在(zai)這里介(jie)紹一種(zhong)基(ji)于ARMLinux的舞臺電腦燈步(bu)(bu)進(jin)電機控(kong)制系統(tong)。
　　系統的總體結構見圖l。系統設計的最(zui)終目(mu)(mu)的是把目(mu)(mu)標(biao)板(ban)嵌入到電(dian)(dian)腦燈(deng)(deng)中,電(dian)(dian)腦燈(deng)(deng)控制臺發送指令(ling)給目(mu)(mu)標(biao)板(ban),目(mu)(mu)標(biao)板(ban)通過網口接收命(ming)令(ling),經ARM內部處理后,通過步進(jin)電(dian)(dian)機(ji)驅(qu)動(dong)(dong)電(dian)(dian)路,產(chan)生步進(jin)電(dian)(dian)機(ji)所需的脈沖(chong)信號(hao),控制電(dian)(dian)腦燈(deng)(deng)完(wan)成相應的動(dong)(dong)作(zuo)。
　目標板(ban)主(zhu)要(yao)包括:AT91RM9200,保證目標板(ban)運行的(de)基(ji)本條件(電源、晶振(zhen)、復位),存(cun)儲器設(she)備(bei)(flash、SDRAM),通信設(she)備(bei)(以太網、DEBUG、RS-422),控(kong)制設(she)備(bei)和檢測(ce)設(she)備(bei)(步進電機驅動、碼盤檢測(ce))。見圖2。
　　AT91RM9200是(shi)目標板的(de)(de)(de)核心,它是(shi)完全(quan)圍繞ARM920T處理(li)器構(gou)建的(de)(de)(de)處理(li)器,有(you)豐富的(de)(de)(de)應用(yong)外設(she)及標準(zhun)的(de)(de)(de)接口,從而為低(di)(di)功耗、低(di)(di)成本(ben)、高性能的(de)(de)(de)計算機應用(yong)提供了(le)解決的(de)(de)(de)方案。由于(yu)AT91RM9200的(de)(de)(de)內部(bu)存(cun)(cun)儲(chu)單(dan)元有(you)限(xian),所以需要外擴存(cun)(cun)儲(chu)器。flash存(cun)(cun)儲(chu)器是(shi)掉電后信息不丟失的(de)(de)(de)存(cun)(cun)儲(chu)器,本(ben)系(xi)統中采用(yong)flash來存(cun)(cun)儲(chu)程(cheng)序和掉電后需要保(bao)存(cun)(cun)的(de)(de)(de)數(shu)(shu)據。由于(yu)SDRAM的(de)(de)(de)成本(ben)低(di)(di)并且存(cun)(cun)儲(chu)速度(du)快的(de)(de)(de)優點,本(ben)系(xi)統選(xuan)用(yong)SDRAM作(zuo)為程(cheng)序的(de)(de)(de)運(yun)行(xing)空間、數(shu)(shu)據及堆棧區。
　　本(ben)系(xi)統要(yao)(yao)求電(dian)腦燈(deng)與(yu)控制臺(tai)通過以太網通信,接收控制臺(tai)的(de)(de)命令,因此在系(xi)統電(dian)路(lu)設(she)計(ji)時需要(yao)(yao)有(you)以太網接口電(dian)路(lu)。為(wei)了兼(jian)容只(zhi)有(you)串口的(de)(de)控制臺(tai),增設(she)l個(ge)串口RS-422。DEBUC調試單(dan)元為(wei)系(xi)統所有(you)調試功能(neng)提供(gong)了l個(ge)單(dan)人口點。步(bu)(bu)進電(dian)機的(de)(de)運行需要(yao)(yao)有(you)驅動(dong)電(dian)路(lu)。舞臺(tai)電(dian)腦燈(deng)控制系(xi)統中(zhong),為(wei)了防(fang)止(zhi)步(bu)(bu)進電(dian)機漏(lou)步(bu)(bu)而造成(cheng)精度不高(gao).采用碼(ma)盤(pan)作感(gan)器,通過碼(ma)盤(pan)接口電(dian)路(lu)將步(bu)(bu)進電(dian)機的(de)(de)位置信息反饋給AT91RM9200,與(yu)控制臺(tai)給出的(de)(de)命令相(xiang)比較,以保證(zheng)電(dian)腦燈(deng)按照要(yao)(yao)求到達(da)指定位置。
本系(xi)(xi)統(tong)(tong)(tong)(tong)經過調試、應用，完全滿足舞臺電(dian)(dian)(dian)腦燈(deng)(deng)的性(xing)(xing)(xing)能(neng)要求，具有明顯(xian)的優勢。與傳統(tong)(tong)(tong)(tong)的單(dan)片(pian)(pian)(pian)(pian)機(ji)電(dian)(dian)(dian)腦燈(deng)(deng)控制(zhi)系(xi)(xi)統(tong)(tong)(tong)(tong)相比(bi)，一臺電(dian)(dian)(dian)腦燈(deng)(deng)只用一片(pian)(pian)(pian)(pian)RAM處理器CPU，而(er)單(dan)片(pian)(pian)(pian)(pian)機(ji)系(xi)(xi)統(tong)(tong)(tong)(tong)可能(neng)需要3—5片(pian)(pian)(pian)(pian)CPU，硬件(jian)電(dian)(dian)(dian)路簡單(dan)，線路板面積(ji)減小，可靠性(xing)(xing)(xing)提(ti)高。本系(xi)(xi)統(tong)(tong)(tong)(tong)采用RAM處理器后，接(jie)口豐富，運算(suan)速度(du)加快，系(xi)(xi)統(tong)(tong)(tong)(tong)功能(neng)加強。對(dui)步進電(dian)(dian)(dian)機(ji)驅動(dong)準確，不會出現(xian)(xian)控制(zhi)轉速脈(mo)沖(chong)丟(diu)失現(xian)(xian)象。本系(xi)(xi)統(tong)(tong)(tong)(tong)采用RAM處理器后，不但保留(liu)串(chuan)行接(jie)口，而(er)且增加了網絡接(jie)口，可以(yi)與PC機(ji)聯網使用，可以(yi)滿足新型電(dian)(dian)(dian)腦燈(deng)(deng)的網絡協議。本系(xi)(xi)統(tong)(tong)(tong)(tong)軟件(jian)采用Linux操作系(xi)(xi)統(tong)(tong)(tong)(tong)，負責嵌入式系(xi)(xi)統(tong)(tong)(tong)(tong)的全部軟、硬件(jian)資源的分配、調度(du)，它在實時性(xing)(xing)(xing)、硬件(jian)的相關依賴(lai)性(xing)(xing)(xing)、軟件(jian)固化(hua)以(yi)及應用等方面，而(er)51單(dan)片(pian)(pian)(pian)(pian)機(ji)系(xi)(xi)統(tong)(tong)(tong)(tong)無法比(bi)擬(ni)。經過試驗，本系(xi)(xi)統(tong)(tong)(tong)(tong)運行穩(wen)定(ding)，操作方便，完全滿足舞臺電(dian)(dian)(dian)腦燈(deng)(deng)的功能(neng)要求。
　　本系統采用ARM處理器移(yi)植Linux操作系統作為控(kong)制(zhi)系統的(de)核心，用鍵盤來控(kong)制(zhi)電(dian)腦(nao)(nao)燈中的(de)步(bu)進(jin)(jin)電(dian)機，共同構成了(le)先進(jin)(jin)的(de)舞臺(tai)電(dian)腦(nao)(nao)燈控(kong)制(zhi)系統。經過對系統硬(ying)件和軟(ruan)件的(de)設計、調試，結果(guo)不但可(ke)以滿足(zu)對電(dian)腦(nao)(nao)燈控(kong)制(zhi)系統嚴格的(de)實時性(xing)(xing)和準確(que)性(xing)(xing)的(de)要求(qiu)，同時證明Linux下的(de)驅動(dong)對步(bu)進(jin)(jin)電(dian)機穩定性(xing)(xing)和可(ke)靠性(xing)(xing)更(geng)佳。

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