【正文】 錄 摘 要 .................................................................................................................................................. 1 ABSTRACT ........................................................................................................................................ 1 正 文 ................................................................................................................................................ 2 1 緒 論 ............................................................................................................................................... 2 信號發(fā)生器現(xiàn)狀 ......................................................................................................................... 2 單片機(jī)在低頻信號發(fā)生器中的應(yīng)用 ............................................................................................. 2 2 系統(tǒng)設(shè)計 ......................................................................................................................................... 3 系統(tǒng)方案的比較 ......................................................................................................................... 3 選題論證 ............................................................................................................................. 3 方案選擇 ............................................................................................................................. 4 芯片選擇模塊 ............................................................................................................................ 4 3 硬件電路的設(shè)計 ............................................................................................................................... 5 系統(tǒng)框圖 ................................................................................................................................... 5 資源分配 .................................................................................................................................. 5 最小單片機(jī)系統(tǒng)設(shè)計 .................................................................................................................. 6 各部分電路原理 ....................................................................................................................... 10 DAC0832 芯片原理 .......................................................................................................... 10 LM324工作原理 .............................................................................................................. 13 電路原理 ................................................................................................................................. 14 4 軟件設(shè) 計 ....................................................................................................................................... 14 主程序流程圖 .......................................................................................................................... 15 方波程序流程圖 ....................................................................................................................... 16 鋸齒波程序流程圖 ................................................................................................................... 17 正弦波程序流程圖 ................................................................................................................... 17 5 仿真結(jié)果 ....................................................................................................................................... 18 6 測試結(jié)論 ....................................................................................................................................... 20 7 結(jié)束語 ........................................................................................................................................... 22 參 考 文 獻(xiàn) ..................................................................................................................................... 23 附 錄 ................................................................................................................................................ 24 致 謝 ................................................................................................................................................ 32 文獻(xiàn)綜述 ........................................................................................................................................... 33 河西學(xué)院本科生畢業(yè)論文（設(shè)計）題目審批表 ......................................................... 錯誤 !未定義書簽。 河西學(xué)院畢業(yè)論文（設(shè)計）指導(dǎo)教師評審表 ............................................................ 錯誤 !未定義書簽。 由于采用 了 LM324 運算放大器，使其電路更 加具有較高的穩(wěn)定性能，性能比高。 關(guān)鍵詞： AT89S51；低頻信號；發(fā)生器；運放器 ABSTRACT This signal generator is designed using AT89S51 as control core and periphery using digital/analog converter circuit (DAC0832), operational amplifier circuits (LM324), button and LED indicator light circuit. AT89S51 and a DAC0832 digitaltoanalog converter ponent of lowfrequency signal generator consisting digital. As a result of the LM324 operational amplifier to the circuit more stable high performance, high performance ratio. This circuit is clear, easy to find failure error, simple and convenient. This design can produce square wave, sawtooth wave, sine wave, and produces waveform in a certain amplitude and frequency range is adjustable, waveform also accurate and smooth. The system is designed to be simple, excellent performance, with a certain degree of practicality. Key words: AT89S51。但是 這種電 路存在波形 質(zhì) 量差，控制 難 ，可 調(diào) 范 圍 小， 電 路 復(fù)雜 和體 積 大等缺點。 單片機(jī)在低頻信號發(fā)生器中的應(yīng)用 當(dāng)今是科學(xué)技術(shù)及儀器設(shè)備高度智能化飛速發(fā)展的信息社會，電子技術(shù)的進(jìn)步，給人們帶來了根本性的轉(zhuǎn)變。 一塊單片機(jī)芯片就是一臺計算機(jī)。 (1) 具有優(yōu)異的性能價格比 單片機(jī)盡可能地把應(yīng)用所需的存儲器 ,各種功能的 I/O 接口集成在一塊芯片內(nèi) ,因而其性能很高 ,而價格卻相對較低廉 ,即性能價格比很高。 (3) 集成度高、體積小、可靠性高 單片機(jī)把各種功能部件集成在一塊芯片上，因而集成度高，均為大規(guī)模或超大規(guī)模集成電路。目前， 許多單片機(jī)已可在 電壓下運行 ,有的已能在 或 下工作，功耗降至 μA級 ,一粒鈕扣電 池就可長期使用。 本文 采用 AT89S51 單片機(jī)和一片 DAC0832 數(shù)模轉(zhuǎn)換器做成的數(shù)字式低頻信號發(fā)生器，它的特點是價格低、性能高，在低頻范圍穩(wěn)定性好、操作方便、體積小 、耗電少等。之所以選單片雙極性是因為其精度高，濾