【正文】 ，當(dāng)本車左轉(zhuǎn)彎、右轉(zhuǎn)彎或剎車時，按下按鈕，此時 (或 或)輸入低電平，并通過： JZ RET_KEY； 無鍵返回 LCALL DISP； 有鍵，延時去抖動 ORL P1， 0FFH MOV A， P1 11 CPL A JZ RET_KEY； 無鍵返回 MOV A， P1 JNB ， S0； 左 轉(zhuǎn) 彎 JNB ， S1； 右 轉(zhuǎn) 彎 JNB ， S2； 剎車 這些程序來判斷汽車的狀態(tài) 。當(dāng)發(fā)送編碼時，開啟定時中斷 T1，以實現(xiàn) 40kHz 的編碼調(diào)制 具體程序 見附錄 4。s five basic principles center on the ball, which was described as large, light, and handled with the hands. Players could not move the ball by running alone, and none of the players was restricted against handling the ball. The playing area was also open to all players, but there was to be no physical contact between players。 smaller gyms used five players on a side, and the larger gyms allowed seven to nine. The team size became generally established as five in 1895, and, in 1897, this was made formal in the rules. The YMCA lost interest in supporting the game because 1020 basketball players monopolized a gymnasium previously used by many more in a variety of activities. YMCA membership dropped, and basketball enthusiasts played in local halls. This led to the building of basketball gymnasiums at schools and colleges and also to the formation of professional leagues. Although basketball was born in the United States, five of Naismith39。實習(xí)這幾個月期間，我拓寬了視野，增長了見識，體驗到社會競爭的殘酷，而更多的是希望自己在工作中積累各方面 的經(jīng)驗，為將來自己走創(chuàng)業(yè)之路做準備。 發(fā)射電路 與接收電路 12 圖 24 接收電路和發(fā)射電路 （ 1） 發(fā)射電路 如圖 24所示， 當(dāng)本車左轉(zhuǎn)彎、右轉(zhuǎn)轉(zhuǎn)彎或剎車時， 狀態(tài)經(jīng)由程序轉(zhuǎn)化成相應(yīng)編碼，通過 80C51 單片機的 15 號引腳 T1 口送出 ， 經(jīng)由三極管放大， 用紅外的方式 發(fā)射出， 傳送給其他車輛 。 ② PSEN:外 ROM 讀選通信號。當(dāng)轉(zhuǎn)向開關(guān)或剎車開關(guān) 閉 合時，其 、 、 三端口相應(yīng)的電平變?yōu)榱恪? 用于接收后車的行駛信息信號， 用于接收前車的行駛信息信號 .電平轉(zhuǎn)換接口電路采用 9013 三極管。單片微型計算機，就是單片機的全稱。相信你的眼光，相信你的選擇 —— 單片機，嵌入式系統(tǒng)設(shè)計的第一步。 單片機 發(fā)展 極為迅速 ,當(dāng)前世界上各大芯片制造公司都推出了自己的單片機 ,從8 位、 16位到 32 位等 ,但它們各具特色 ,互成互補 ,為單片機的應(yīng)用提供廣闊的天地。 1971 年 11 月， Intel 推出 MCS4微型計算機系統(tǒng)（包括 4001 ROM 芯片、 4002 RAM芯片、 4003 移位寄存器芯片和 4004 微處理器 ）其中 4004（下圖）包含 2300 個晶體管，尺寸規(guī)格為 3mm 4mm，計算性能遠遠超過當(dāng)年的 ENIAC，最初售價為 200 美元。 說的清晰點，單片機就是有著好多腳的集成芯片，通過特定程序控制這些引腳的電平的特定變化，從而起到自動控制的需求。 見圖 23。本車轉(zhuǎn)彎或剎車時其動作經(jīng)按鍵轉(zhuǎn)化為電信號通過單片機，再轉(zhuǎn)化為其他信號通過單片機 T1 口發(fā)射出去，通知前后車，你車下一步的動作，讓別人做出相應(yīng)準備。 b 、 VPD 功能：在 Vcc 掉電 情況下，接備用電源。若當(dāng)間隔位的高電平脈寬大于 3ms 時，接收結(jié)束，然后根據(jù) 累加器A 中的脈沖個數(shù)，使相應(yīng)的輸出口（ ～ ）為低電平，驅(qū)動顯示 電路。這將非常有利于我們今后的學(xué)習(xí)和工作。 Australia, China, and India between 1895 and 1900。s ball is in (7274 cm) in circumference. The covering of the ball is leather, rubber, position, or synthetic, although leather covers only are dictated by rules for college play, unless the teams agree otherwise. Orange is the regulation color. At all levels of play, the home team provides the ball. Inflation of the ball is based on the height of the ball39。當(dāng)外中斷允許并且紅外線接收頭輸出脈沖編碼時，中斷程序?qū)崟r接收編碼并且對脈沖個數(shù)進行計數(shù)，根據(jù)接收脈沖個數(shù)分別控制 ～ 顯示端口。 RC 構(gòu)成微分電路，上 電瞬間 RST 引腳獲得高電平，隨著電容 C1 的充電， RST 引腳的高電平將逐漸下降。 80C51 芯片大大降低了功耗，并引入了低功耗管理模式，使低功耗具有可行信。在數(shù)據(jù)幀接收時，中斷將被關(guān)斷，并且對第一（起始位）位碼的碼寬進行驗證。 第二章 信息監(jiān)測系統(tǒng)的組成及工作原理 系統(tǒng)的組成 與工作原理 本 系統(tǒng)電路主要有：單片機最小系統(tǒng)；發(fā)射 /接收裝置；左轉(zhuǎn)彎、右轉(zhuǎn)彎、剎車 、超車 指示等組成。 Zilog 公司于 1976 年 開發(fā)的 Z80 微處理器，廣泛用于微型計算機和工業(yè)自動控制設(shè)備。本文介紹了一種簡易汽車行駛信息接收與發(fā)送器的設(shè)計 ,敘述了系統(tǒng)基本組成結(jié)構(gòu)，該設(shè)計能自動顯示前后車的轉(zhuǎn)向、剎車情況并用聲響提醒 ,對提高汽車行車安全具有一定的現(xiàn)實意義。同時，汽車行駛監(jiān)測儀的完善性、安全性、可靠性也將是汽車品牌之間競爭的另一大亮點。 1975 年 4月， MITS 發(fā)布第一個通用型 Altair 8800，售價 375 美元，帶有 1KB 存儲器。一方面， 8 位單片機的性能能夠滿足一般的控制要求，技術(shù)、資源較為成熟，已經(jīng)形成一個體系，初學(xué)者可以很容易獲取相關(guān)資料；另一方面，我們 5 計算機中，一個 byte 的數(shù)據(jù)時 8bit 組成的， 8 位單片機能夠使初學(xué)者更好的理解，容易接受。發(fā)送數(shù)據(jù)時，中斷將被禁止。芯片設(shè)計是基于所有操作必須由單片機控制，操作命令可通過串行通信接口 SPI 送入；同時采用多電平直接模擬量存儲技術(shù)，每個采樣值直接存儲在片內(nèi)的閃爍存儲器中，因此能夠非常真實、自然地再現(xiàn)語音、音樂、音調(diào)和效果聲，避免了一般固體錄音電路因量化和壓縮造成的量 化噪聲和 “ 金屬聲 ”； 采樣頻率為 ，片內(nèi)信息存于閃爍存儲器中 ， 可在斷電情況下保存 100 年 (典型值 )， 反復(fù)錄音 10萬次。 P3口還具有第二功能，用于特殊信號輸入輸出和控制信號（屬控制總線）。結(jié)束后延時 60ms，再轉(zhuǎn)檢測程序循環(huán)。s disorder (a related condition in which the baby develops in an apparently normal manner through age five months, and then begins to lose municative and social interaction skills). There is also evidence of a higher proportion of perinatal plications (plications arising around the time of giving birth) among children with autistic symptoms. These plications include maternal bleeding after the first trimester and meconium in the amniotic fluid. (Meconium is a substance that accumulates in the bowel of the developing fetus and is discharged shortly after birth.) Some evidence suggests that the use of medications during pregnancy may be related to the development of autistic symptoms. As newborns, children with autistic behaviors show a higher rate of respiratory illness and anemia than healthy children. ALLERGIES, INFECTIONS, AND IMMUNIZATIONS. Some professionals believe that autistic disorders may be caused by allergies to particular fungi, viral infections, and various foods. No controlled studies have supported these beliefs, but some parents and professionals report improvement when allergens and/or certain foods are eliminated from the diet. Viral infections of the mother, such as rubella, or of the young child, such as encephalitis, mumps, and measles, occasionally appear to cause autistic disorders. The mon childhood immunization series known as MMR (measles, mumps, rubella) has recently e under scrutiny as a possible cause of some autistic can make a true claim to being the only major sport that is an American invention. From high school to the professional level, basketball attracts a large following for live games as well as television coverage of events like the National Collegiate Athletic Association (NCAA) annual tournament and the National Basketball Association (NBA) and Women39。s basketball. Until World War II, basketball became increasingly popular in the United States especially at the high school and college levels. After World War II, its popularity 29 grew around the world. In the 1980s, interest in the