1、外文文獻(xiàn)資料收集：蘇州大學(xué) 應(yīng)用技術(shù)學(xué)院 10電子（學(xué)號1016405041） 林俊涵 the system design of wireless basketball timer based on mcu and nrf24l01 abstract: currently, basketball players must know the progress well in time in the game, the presence of electronic timer with led display influences the basketball games. the wired o

2、peration influences the control distance, control reliability, control efficiency and so on. so how to make it longer, anti-interference, easy operation and high efficiency is a difficult problem. a kind of wireless basketball timer is designed based on micro-computer unit (mcu) and wireless nrf24l0

3、1 module to compensate for the existing disadvantages, which has led digital tube of large size for the section number display and middle size for game display and 24s display.the user is easy to carry and control the timer wirelessly at any place in the basketball court using the sending control de

4、vice. the test results show that the system, easy to control and stable to operate, is reliable to transmit the wireless data. keywords: basketball timer, mcu , nrf24l01 , system design , wireless communication 1. introduction in the current basketball games, players need to know 24 sec and the rema

5、ining time of each period match in time; electronic timer with the advantages of its convenient operation, compact size and visualization has been widely used in basketball games. nba timing and score system was designed by a chip called 8031 of mcs-51.the system consists of time counting, score cou

6、nting, keyboards and display sub-systems (luo-sheng, 2004). a new timing and scoring equipment for basketball match was designed and made by chinese basketball association, used in 2004 cba league match and nba in beijing, which was helpful for the present timing and scoring equipment specialized in

7、 sport venues and has great room for development and application (zhang et al., 2006).the control system of basketball scoreboard with 16*16 matrix led was designed based on single-chip microcomputer, which could be off-line and continuous long-term operation and so on (wei-yu et al., 2008).the desi

8、gn of hardware and software of timing-score system was achieved using 89c51, which had the functions of the total time and the total countdown, with its features of modular design, simple process structure, clear mandate and easy to prepare (han et al., 2009).the device was based on p89v51rb2 single

9、-chip microcomputer, which can show the current section, the remaining time and the score, according to actual situations, the time and score can be amended (rong-jian et al., 2010).the countdown circuit was designed based on stc89c52 single-chip microcomputer, which can countdown 999 days, accurate

10、 to seconds. the result of the experiment demonstrates the correctness and feasibility of the design (ze-shi, 2011).although these timer or score systems are convenient to use, there are some disadvantages during the use of them, some are inconvenient for both players as a result of small size and t

11、he position of use and some are inconvenient to install and repair and low efficiency and reliability and so on, because of the long cable connect of between sending device and receiving device.in the current chinese market, a electronic timer includes a sending device which can be moved and a recei

12、ving device which is fixed on or over the basketball frame, can provide real-time information of time for players and audiences.still it is easy to cause bad connect because of the frequent connect of sending device and receiving device.in the basketball game, the basketball referee can need to move

13、 frequently, which is away from the sending device and cannot carry it due to the wire and must pass some information about the game to the live operator operating the sending device, which can lead to inaccurate and no timely information.according to the above reasons, a system based on mcu and wir

14、eless chip can be put forward which can send the information wirelessly and easy to carry, etc.2. basketball timer basketball timer is an indispensable instrument in basketball games, which used to show the information of time and quarter of the game.in addition, in order to accelerate the game, pla

15、yers should shoot at the basket within 24 sec, otherwise it will break the rule. in common, basket timer is connected with receiver from transmitter by rs232 serial.however, the electric cables are fragile and difficult to operate.so, wireless data transmission is a better choice. some short distanc

16、e wireless data communication such as bluetooth, zigbee, wi-fi that work on 2.4ghz, but these technologies are complicated and cost more, it is difficult to meet the rapid development and low cost requirement in general applications.nrf24l01 module is a new single chip rf transceiver device launched

17、 by norway nordic semiconductor, built-in frequency synthesizer, a power amplifier, a crystal oscillator, a modulator module (zhang et al., 2004) and fused with enhanced shock burst technology, with advantages of high transmission rate, small volume and low power consumption.nrf24l01 chip with pcb a

18、ntenna has 100 meters effective transmission distance, which will be satisfied with the design requirement. lq-nrf24l01 module of beijing long-qiu intelligent technology center is used in this system (xiu-mei and nai-an, 2004).in this system, the user (operator) can set, modify and halt the match ti

19、me by using its keyboard module.at the same time the match quarters changed, 24s ball-control time started and stopped. the system was easy to carry; anywhere within 100 meters from the timer display system it can be operated effectively. the overall system block diagram is shown in fig. 1.fig. 1: t

20、he system block diagram 3. hardware design of the system3.1. keyboard module: the keyboard module is mainly used to set and modify the section number, the game time and stop time of the section, 24 sec of the start and stop operation.considering the electronic basketball timer required function and

21、easy to extend, a 4*4 matrix keyboard is used.mcu scans the matrix keyboard and reads the key value through p0 port per 100 ms. the interface of the circuit is shown in fig. 2.fig. 2: keyboard and mcu interface circuit 3.2. sending and receiving (lq-nrf24l01) module: the system proposed a short dist

22、ance of wireless data transmission design method based on the 2.4 ghz nrf24l01 chip, which has the advantages of low cost, low power consumption, fast development etc.nrf24l01 is a monolithic rf transceiver chip, with automatic response and re-transmitting function and the data can be wrote through

23、the spi bus.nrf24l01 chip has very low power consumption, for example, working current is only 9 ma and receiving current only for 12.3 ma while -6dbm power is transmitted.and with 125 channels available and a variety of low power modes so that the energy-saving design more convenient, while the mar

24、kets have many other modules based on nrf24l01 and easy to buy.lq-nrf24l01 module is used in the design. nrf24l01 has several working modes; sender-receiver model is only introduced, which has three modes such as enhanced shockburst tm, shockburst tm and direct mode.and that can be determined by con

25、figuration register.for the enhanced shockburst tm mode, inside fifo stack area is used and in order to minimize energy consumption the data are input with low speed, but are emitted with high speed (1 mbps). so enhanced shockburst tm technology can reduce average working current of the system.in th

26、e mode, nrf24l01 can process the prefix and crc check code automatically, which is completed by crc encoding and decoding circuit (hong-cai, 2008). during data transmission, the predix and crc check code are added automatically, meanwhile ce signal is set high for 10 us until the completion of the t

27、ransmission.while receiving data, the prefix and crc check code will be deleted. interface circuit diagram is shown in fig. 3 between lq-nrf24l01 module and mcu, csn port of the module is a chip select with active low level, sck port for serial clock (spi clock).due to no standard spi bus interface

28、for atmel89c51 mcu, the function of spi bus is simulated by the software.miso is a host input / slave output port and mosi is a slave input/host output data port. irq port is the interrupt signal line, while data is sent successfully irq signal changed into low level.ce port is mode control of the c

29、hip, under the condition of low csn level, nrf24l01 status is decided by ce and nrf24l01 configration register.fig. 3: lq-nrf24l01module and mcu interface circuit 3.3. led display module:in order to improve the display effect and increased visibility, led digital display device is used in the system

30、. according to the display actual situation, led digital tubes of middle size are adopted to display the section number and the game time and led digital tubes of large size are adopted to display control time.because of these led digital tubes are drove by higher volt which 51-mcu cannot afford, ul

31、n2803 driver chip with darlington tube of sufficient magnification is used (li et al., 2011) and the schematic diagram is shown in fig. 4. in order to reduce the complexity of the system, the dynamic scan mode is used to control the led display here. the valid bit display method can improve the mcu

32、efficiency, where once the bit is a valid value it could be displayed. fig. 4: led digital tube and mcu interface circuit 4. software design of the system c or asm language can be used to design the mcu program with 51 kernels. and c language with the characteristic of simple and easy to understand,

33、 so it could accelerate the developed program speed,at the same time convenient transplantation between different mcus.asm language is relatively difficult to read and graft and the rate of development is slower, but it has the highest executable program efficiency (hong-cai, 2008; yun-xin et al., 2

34、009).c language is chosen in the system because of the current c language in the powerful compiler can already has the similar efficiency compared with assembler language. wireless basketball timer software design mainly includes the transmitting and receiving parts.4.1. transmitting program design:

35、 main functions of the transmitting part are as follows: at first,the initialization of mcu and nrf24l01 module and nrf24l01 is set transmitting mode, then the keyboard is scanned at fixed time and the key value is got and that is transmitted wirelessly which is encoded by the nrf24l01 module. trans

36、mitting mode configuration of nrf24l01 module is as follows (zhu and zhang, 2011): （1）set csn high,ce low and configuring mode （2）delay above 130 us （3）configuration data is written to the lq-nrf24l01module by i/o port of mcu （4）set csn low, completing configuration （5）set the ce high, nrf24l01 for

37、tx mode （6）delay above 130 us （7）data to be transmitted is written to the lq-nrf24l01 fifo buffer by i/o port of mcu （8）set ce is low, transmitting through shockburst tx mode （9）clear fifo buffer after completing transmission （10）the program diagram is shown in fig. 5.fig. 5: transmitting program di

38、agram 4.2. receiving program design:main functions of the receiving part are as follows: while a valid packet could not be received, the data of different display buffers are read and displayed on the corresponding led digital tube. and while a valid packet could be received, the receiving control s

39、ystem is interrupted and the received data in the nrf24l01 module are read and stored to the corresponding display buffers. program flow diagram is shown in fig. 6.fig. 6: receiving program diagram, (a) main program diagram of the control system, (b) interrupt service routine diagram receiving mode

40、configuration of nrf24l01 module is as follows (zhu and zhang, 2011):（1）set ce high, nrf24l01 for receiving mode（2）while rx_dr bit of the status register becomes to high level, that confirms the fifo buffer of nrf24l01 has received the data and mcu reads these data by the interrupt mode（3）clear fifo

41、 buffer after completing to read data5. conclusionthe study introduced a kind of wireless basketball timer based on the mcu and nrf24l01 module, the current some problem can be solved such as wiring inconvenient an so on.the system has the advantages of simple structure, convenient installation and

42、repair, convenient operation, low cost and flexible layout, so it has great value in practical generalization and application.中文翻譯稿翻譯：蘇州大學(xué) 應(yīng)用技術(shù)學(xué)院 10電子（學(xué)號1016405041） 林俊涵基于單片機(jī)和nrf24l01的無線籃球定時器的系統(tǒng)設(shè)計摘要：目前，籃球運(yùn)動員必須及時地很好的知道比賽的進(jìn)展情況，帶有l(wèi)ed顯示屏的電子定時器的存在對籃球比賽產(chǎn)生了很多影響。有限操作影響控制的距離，控制的可靠性和控制的有效性等等。因此如何使它更長距離控制，有更高的抗

43、干擾性，有更簡便的操作和高度的有效性是一個困難的問題。一種基于單片機(jī)（mcu）和無線芯片nrf24l01設(shè)計模塊的無線籃球計時器可以用來補(bǔ)償以上的缺點，它有大尺寸led數(shù)碼管用來段數(shù)顯示和中型的尺寸作為比賽和24秒的顯示。裁判可以在籃球場上任何地方使用發(fā)送裝置對定時器進(jìn)行控制，并且它很容易攜帶。試驗結(jié)果表明，該系統(tǒng)穩(wěn)定，易于控制和操作，使無線傳輸數(shù)據(jù)具有可靠性。關(guān)鍵詞：籃球計時器，單片機(jī)，nrf24l01，系統(tǒng)設(shè)計，無線通信第1章 引言在目前的籃球比賽中，運(yùn)動員需要知道24秒，以及比賽期間每個時間段剩余時間;電子計時器以其簡便的操作，體積小和易于觀看的優(yōu)勢，已被廣泛應(yīng)用于籃球比賽。nba使用由

44、8031mcs-51構(gòu)建的計時和評分系統(tǒng)。該系統(tǒng)由計時，計分，鍵盤和顯示子系統(tǒng)構(gòu)成。 一個由中國籃球協(xié)會設(shè)計和制造的新的籃球比賽計時計分設(shè)備，用于2004年北京cba和nba聯(lián)賽。這有助于在體育場館的目前用于計時計分的專用設(shè)備的發(fā)展和應(yīng)用，同業(yè)具有巨大的發(fā)展空間（張等人.2006）。16*16矩陣led籃球計分牌控制系統(tǒng)是基于單片機(jī)設(shè)計的，并且可以長期連續(xù)地離線運(yùn)作等。計時評分系統(tǒng)的硬件和軟件的設(shè)計是采用89c51單片機(jī)實現(xiàn)的，具有總時間計算和倒計時功能，其設(shè)計模塊化，程序結(jié)構(gòu)簡單，指令清晰并且容易配備。該設(shè)備是基于p89v51rb2單片機(jī)，它可以顯示當(dāng)前部分，剩余時間和得分，根據(jù)實際情況，時

45、間和分?jǐn)?shù)可以修改。倒計時電路是基于stc89c52單片機(jī)設(shè)計的，它可以倒計時999天，精確到秒。實驗結(jié)果證明了設(shè)計的正確性和可行性。雖然這些定時器和評分系統(tǒng)方便使用，但他們在實際使用中仍然存在一些弊端，由于小尺寸和擺放位置導(dǎo)致了雙方球員的不便，還有難以安裝和修理的不便，這些都是發(fā)送裝置和接收裝置之間的長電纜導(dǎo)致的。在目前的中國市場，一個由可以移動的發(fā)送裝置和一個固定在籃球框的接收裝置制成的電子計時器，便可以為運(yùn)動員和觀眾提供時間的實時信息。還是很容易造成因為頻繁地連接發(fā)送和接收設(shè)備而造成的接觸不良。在籃球比賽中，籃球裁判可能需要經(jīng)常移動，發(fā)送設(shè)備因為電線的緣故不能隨身攜帶，但必須傳遞關(guān)于比賽的

46、資料，這就要遠(yuǎn)離發(fā)送設(shè)備。只能由操作人員操作發(fā)送設(shè)備，這可能會導(dǎo)致信息的不準(zhǔn)確和不具有實時性。基于以上原因，基于單片機(jī)和無線芯片可以做出具有無線傳輸和方便攜帶等功能的系統(tǒng)。第2章 籃球計時器籃球計時器在籃球運(yùn)動中是不可缺少的工具，用于顯示時間和比賽階段信息。此外，為了加快比賽節(jié)奏，選手必須在24秒內(nèi)投籃，否則將算作犯規(guī)。一般而言，籃球定時器通過連接rs232串口進(jìn)行信號收發(fā)。然后電纜是脆弱并且難以操控的。因此無線數(shù)據(jù)傳輸是更好的選擇。一些短距離無線數(shù)據(jù)通信技術(shù)，如藍(lán)牙，wifi等工作在2.4ghz，但是這些技術(shù)復(fù)雜，成本高，難以滿足快速發(fā)展的一般應(yīng)用的低成本要求。nrf24l01模塊是一個由挪

47、威北歐半導(dǎo)體推出新的單片射頻收發(fā)裝置，內(nèi)置頻率合成器，功率放大器，晶體振蕩器，調(diào)制器模塊并融合增強(qiáng)的沖擊地壓技術(shù)，具有傳輸速率高，體積小，功耗低的優(yōu)點。基于nrf24l01芯片的pcb天線有100米的有效傳輸距離，這滿足設(shè)計要求。北京長秋智能技術(shù)中心的lq-nrf24l01應(yīng)用于本系統(tǒng)。在這個系統(tǒng)中，用戶（操作員）可以通過使用鍵盤模塊建立，修改和停止比賽的時間。包括比賽段的改變，24秒的開始和停止。該系統(tǒng)便于攜帶，在計時器顯示系統(tǒng)100米范圍內(nèi)的任何地方都可以有效地操作。該系統(tǒng)總體框架如圖1所示。圖1 系統(tǒng)模塊框圖第3章 該系統(tǒng)的硬件第3.1.節(jié) 鍵盤模塊鍵盤模塊主要用于設(shè)置和修改比賽的階段，

48、比賽開始時間和終止時間，24秒的啟動和停止。考慮到電子籃球定時器所需要的功能和已與擴(kuò)展的特性而使用了4*4的矩陣鍵盤。單片機(jī)掃描矩陣鍵盤通過p0口每100毫秒讀取一次鍵值。該電路的接口，如圖2所示。圖2 鍵盤和單片機(jī)的接口電路第3.2.節(jié) 發(fā)送和接收（lq-nrf24l01）模塊該系統(tǒng)提出了一種基于nrf24l01芯片工作頻率為2.4 ghz的短距離無線數(shù)據(jù)傳輸?shù)脑O(shè)計方案，具有成本低，功耗低，快速發(fā)展等特點。nrf24l01是單片射頻收發(fā)芯片，具有自動應(yīng)答、轉(zhuǎn)發(fā)功能，可以通過spi總線寫入數(shù)據(jù)。nrf24l01具有非常低的功耗，例如當(dāng)發(fā)送頻率為-6dbm時工作電流只有9ma，接收時電流為12.3ma。有125個頻道和多種低功耗模式，使節(jié)能設(shè)計更方便，而市場上也有許多其他基于nrf24l01的模塊，并且很容易購買到。本設(shè)計中應(yīng)用lq-nrf24l01模塊。nrf24l01具有多種工作模式，本課題只介紹信號收發(fā)模式，它還具有三種模式如增強(qiáng)型，節(jié)能型和直接模式。這可以通過配置寄存器確定。在增強(qiáng)模式下，在先進(jìn)先出的堆棧區(qū)使用，以減少能量消耗，但是以高速發(fā)射的(速度高達(dá)1mbps)。因此，增強(qiáng)型單片機(jī) tm技術(shù)可以降低系統(tǒng)的平均工作電流。在該模式下，nrf24l01的可自動加工前綴和crc校驗碼，