有關(guān)數(shù)據(jù)傳輸系統(tǒng)設(shè)計的中英文翻譯.doc

1、.NRF905 is the Nordic company introduced single-chip RF transceiver 5 mm, working in the 433 / 868 / 915 MHz three ISM channels (free of charge). NRF905 can automatically complete the processing of prefix and CRC (cyclical redundancy check), can be done automatically on-chip hardware Manchester enco

2、ding / decoding, the use of SPI communication with a microcontroller interface, configuration is very convenient. Its very low power consumption, -10dBm output power when it was launched only 11mA current, the current in the receiving mode is 12.5mA. NRF905 non-real-time data transmission methods, n

3、amely, a data transmitter, receiver received after the first items on-chip memory, outside the MCU can chip in when necessary and then to fetch. There are two operating modes and two energy-saving modes, respectively idle mode, standby mode, ShockBurst TM receive mode and sent Shock2Burst TM mode. S

4、everal models from the outside world by controlling the CPU nRF905 the three-pin PWR_UP, TRX_CE TX_ EN and the high low to decide, PWR_UP TRX_CE TX_EN mode RF delivery mode SPI bus outside MCU configuration nRF905 through the internal registers, read and write data to their home or for standby power

5、-down mode. NRF905 power consumption in standby mode for 40 A in power-down mode, power consumption is 2.5 A.nRF905 state output nRF905 a three-pin output for the state, namely: CD (Carrier Detection), AM (address matching) and DR (data ready), are high-effective. NRF905 in a receive mode, if the de

6、tected frequency of the receiver Carrier, home CD for high detection carrier then address bytes in the data, and if their address has been configured to receive the same, higher home AM; if detected receive data in the CRC check it correctly, the effective storage data byte, home to high-DR. In addi

7、tion, the nRF905 there is a clock output pin uPCLK for users choose to use. By configuring the internal registers, can change its output frequency, which is useful for debugging. Wireless systems need at least one or two devices in one, and if there are problems when debugging is hard to judge which

8、 side of the fault. May amend nRF905 register with oscilloscope observation uPCLK whether changes in output, to determine its hardware circuit and the CPU operating nRF905 procedures is correct, and thus judged the equipment is working properly. nRF905 data interfaces SPI bus through the external MC

9、U configuration nRF905 the internal registers and send and receive data. NRF905 SPI bus, including four-pin: CSN (SPI enable), SCK (SPI clock), MISO (all from the Lord) and MOSI (from the main links). NRF905 here from the plane, the SPI clock with a wide range from 1 Hz to 10 MHz, the MCU written co

10、ntrol procedures need not expect the accuracy of the time. SPI bus each operation must be in order to pin the falling edge of CSN, CSN low effective, the data bus of the clock rising edge effectively. MCU on the SPI bus operators either two ways: reading and writing. During read operation, the first

11、 CSN buy low, and then MOSI data online.Reading said that the output of a command byte at the same time, nRF905 in MI2SO online data output a byte of data that state information, and then output a byte address, valid data follow behind. Written in relatively simple operation, the MCU first CSN dragg

12、ed down, and then write out an order online MOSI bytes and bytes of data can be. nRF905 register allocation .NRF905 register within five categories: First, RF configuration register, a total of 10 bytes, including the center frequency, wireless transmitter power configuration, receiver sensitivity,

13、send and receive data bytes effective, receiving address configuration, and other important information is sent two data register, a total of 32 bytes, the MCU to the field of data need to write here; Third, it is sent addresses, a total of four bytes, a transceiver equipment to the normal communica

14、tion, it is necessary to send the address of the transmitter and receiver end of the receiving address configuration the same four is receiving data register, a total of 32 bytes, nRF905 receive data on the effective storage in these registers, the MCU can be read here when necessary; 5 is the state

15、 register, a byte containing address matching and data ready information, not general. MCU to operate the register, to follow the provisions of the operation nRF905 order, the following commonly used seven kinds are a byte: write RF configuration, Reading RF configuration with four binary bit, byte

16、said from the beginning of which read bytes, sent written data (H 20), Reading sent the data (21 H), write sent Address (22H), Reading sent Address (H 23) and receiving reading Data (24 H). For more information on the register can see nRF905 data sheet. nRF905 the working process.NRF905 normal worki

17、ng before MCU should be required to write configuration registers, or in accordance with the default configuration. Subsequent work is primarily twofold: send data and receive data. When data is transmitted, the MCU should be placed in standby mode first nRF905 (PWR_UP pin high, low TRX_CE pin), and

18、 then sent through the SPI bus to the address and data to be sent into the corresponding registers, after the nRF905 placed sent mode (PWR_UP, TRX_CE and TX_EN Whole home high), the data is automatically sent out by the antenna. If the RF configuration registers in the auto-bit (AUTO_RETRAN) as a va

19、lid data packet will be repeated has been the outward until the MCU TRX_CE lowered, the model sent out so far. In order to more reliable data transmission, the proposed multi-use of such methods. Receive data, the MCU in the nRF905 first in the standby mode configuration of the RF receiver in the ad

20、dress register write, and then their home in the receive mode(PWR_UP = 1, TRX_CE = 1, TX_EN = 0), nRF905 will automatically receive the air carrier. If the addresses match, and received the correct effective data validation, DR pin will automatically buy high, the MCU in the detection of this signal

21、 can be diverted to its standby mode through the SPI bus from receiving data in the register read out effective data. nRF905是Nordic挪威公司推出的單片射頻收發(fā)器，工作于 433/868/915 MHz 3個ISM頻道(可以免費使用)。nRF905可以自動完成處理字頭和CRC(循環(huán)冗余碼校驗)的工作，可由片內(nèi)硬件自動完成曼徹斯特編碼/解碼，使用SPI接口與微控制器通信，配置非常方便。其功耗非常低，以-10dBm的輸出功率發(fā)射時電流只有11mA，在接收模式時電流為12.

22、5mA。nRF905傳輸數(shù)據(jù)時為非實時方式，即發(fā)送端發(fā)出數(shù)據(jù)，接收端收到后先暫存于芯片存儲器內(nèi)，外面的MCU可以在需要時再到芯片中去取。nRF905一次的數(shù)據(jù)傳輸量最多為32 B。nRF905片內(nèi)集成了電源管理、晶體振蕩器、低噪聲放大器、頻率合成器、功率放大器、通信協(xié)議控制等模塊，曼徹斯特編碼/解碼由片內(nèi)硬件完成，無需用戶對數(shù)據(jù)進(jìn)行曼徹斯特編碼，因此使用非常方便。nRF905有兩種工作模式和兩種節(jié)能模式。兩種工作模式是ShockBurstTM接收模式和ShockBurstTM發(fā)送模式，兩種節(jié)能模式分別是關(guān)機模式和空閑模式。nRF905的工作模式由TRX-CE、TX-EN和PWR-UP三個引腳決

23、定。由于nRF905具有ShockBurstTM功能，使得nRF905不需要使用昂貴的高速微控制處理器對數(shù)據(jù)處理/時鐘恢復(fù)，也能達(dá)到較高的數(shù)據(jù)率。通過在芯片上將所有的高速信號處理變?yōu)樯漕l通信協(xié)議，nRF905芯片提供了一個具有微控制器能力的SPI接口，數(shù)據(jù)率由具有微控制器功能的接口速率自行設(shè)定。收發(fā)電路的數(shù)字部分是一個低速率電路，而收發(fā)電路的射頻鏈接卻是一個處于最高速率的電路，整個電路要通過變速才能解決速率上的差異。nRF905芯片的ShockBurstTM模式減少了 在這一過程中的平均電流消耗。在ShockBurstTM RX模式中，當(dāng)一個有效地址的數(shù)據(jù)包被接收時，能夠通過AM和R兩個信號外

24、送給MCU 。在ShockBurstTMTX模式中，nRF905芯片自動地完成報頭的生成和CRC校驗，當(dāng)發(fā)送過程完成后，能夠通過DR信號外送給MCU，發(fā)送工作已經(jīng)完成。這樣可以降低MCU對內(nèi)存的要求，使得MCU實現(xiàn)了低成本，同時也縮短了軟件的開發(fā)周期. nRF905的工作模式及設(shè)置。nRF905 有兩種工作模式和兩種節(jié)能模式，分別為掉電模式、待機模式、ShockBurst TM接收模式和Shock2Burst TM發(fā)送模式。這幾種模式由外界CPU通過控制nRF905的3個引腳PWR_UP、TRX_CE 和TX_ EN的高低電平來決定，外界MCU通過SPI總線配置nRF905的內(nèi)部寄存器，讀寫數(shù)

25、據(jù)時必須把其置為待機或掉電模式。nRF905在待機模式時功耗為40A ,在掉電模式時功耗為2.5A。nRF905的狀態(tài)輸出nRF905有3個引腳用于狀態(tài)輸出，分別是：CD(載波檢測)、AM(地址匹配)和DR(數(shù)據(jù)就緒)，均為高電平有效。nRF905在處于接收模式時，若檢測到接收頻率段的載波，就置CD為高；接著檢測載波數(shù)據(jù)中的地址字節(jié)，若與本身已配置的接收地址相同，則置AM為高;若再檢測到接收數(shù)據(jù)中的CRC校驗正確，則存儲有效數(shù)據(jù)字節(jié)，置DR為高。此外，nRF905還有一個時鐘輸出引腳uPCLK，供用戶選擇使用。通過配置內(nèi)部寄存器，可改變其頻率輸出，這一點在調(diào)試時很有用。無線系統(tǒng)至少需要一發(fā)一收

26、兩個設(shè)備，調(diào)試時若出現(xiàn)問題很難判斷是哪一方的故障?？梢酝ㄟ^修改 nRF905的寄存器，用示波器觀察uPCLK輸出是否變化的方法，來判斷其硬件電路和CPU操作nRF905的程序是否正確，從而判斷該設(shè)備是否工作正常。nRF905 的數(shù)據(jù)接口。外圍MCU通過SPI總線配置nRF905的內(nèi)部寄存器和收發(fā)數(shù)據(jù)。nRF905的SPI總線包括4個引腳：CSN(SPI 使能)、SCK(SPI時鐘)、MISO(主入從出)和MOSI(主出從入)。這里nRF905為從機，其SPI的時鐘范圍很寬，可以從1Hz10MHz，因此MCU在寫控制程序時不必苛求時間的準(zhǔn)確度。SPI總線的每次操作都必須在使能引腳CSN的下降沿開始，CSN低電平有效，總線上的數(shù)據(jù)在時鐘的上升沿有效。MCU對SPI總線的操作不外乎兩種方式：讀和寫。在進(jìn)行讀操作時，先把CSN置低，然后在 MOSI 數(shù)據(jù)線上輸出一個表示讀命令的字節(jié)，與此同時，nRF905會在MISO數(shù)據(jù)線上輸出一字節(jié)表示狀態(tài)信息的數(shù)據(jù)，隨后輸出一地址字節(jié)，后面跟隨有效數(shù)據(jù)。在進(jìn)行寫操作時比較簡單，MCU先把CSN拉低 ,然后在MOSI線上輸出寫命令字節(jié)和數(shù)據(jù)