【正文】 s nRF905 is monitoring the air for ining munication. 3. When the nRF905 senses a carrier at the receiving frequency, Carrier Detect (CD) pin is set high. 4. When a valid address is received, Address Match (AM) pin is set high. 5. When a valid packet has been received (correct CRC found), nRF905 removes the preamble, address and CRC bits, and the Data Ready (DR) pin is set high. 6. MCU sets the TRX_CE low to enter standby mode (low current mode). 7. MCU can clock out the payload data at a suitable rate via the SPI interface. 8. When all payload data is retrieved, nRF905 sets Data Ready (DR) and Address Match (AM) low again. 9. The chip is now ready for entering ShockBurst ?RX, ShockBurst ?TX or power down mode. If TX_EN is set high while TRX_CE is kept high, the nRF905 would enter ShockBurst?TX and start a transmission according to the present contents in the SPIregisters. If TRX_CE or TX_EN is changed during an ining packet, the nRF905 changes mode immediately and the packet is lost. However, if the MCU is sensing the Address Match (AM) pin, it knows when the chip is receiving an ining packet and can therefore decide whether to wait for the Data Ready (DR) signal or enter a different mode. To avoid spurious address matches it is remended 。A Rx433 16OFF Rx868/915 16OFF Ma Reduced Rx 16OFF mA Tx 10dBm 16OFF 30 mA Tx 6dBm 16OFF 20 mA Tx 2dBm 16OFF 14 mA Tx 1dBm 16OFF 11 mA Conditions: VDD = , VSS = 0V, TA = 27186。A StandBy 164 285181。A StandBy 84 275181。A StandBy 202 210181。A StandBy 82 185181。A StandBy 201 170181。A StandBy 121 150181。A StandBy 41 130181。A StandBy 16 135181。A StandBy 8 125181。A StandBy 20OFF 46181。A StandBy 12OFF 27181。58 KHZ RGFSK Data rate 100 KBPS fCH433 Channel spacing for 433MHz band 100 KHZ fCH868/915 Channel spacing for 868/915MHz band 200 KHZ Transmitter operation PRF10 Output power 10dBm setting6) 7 10 11 dBm PRF6 Output power 6dBm setting6) 3 6 9 dBm PRF2 Output power –2dBm setting6) 6 2 2 dBm PRF10 Output power 10dBm setting 6) 14 10 6 dBm PBW 20dB bandwidth for modulated carrier 190 KHZ ITX10dBm Supply current 10dBm output power 30mA ITX10dBmSupply current 10dBm output power 11mAReceiver operationIRX Supply current in receive mode mA RXSENS Sensitivity at %BER 100 dBm RXMAX Maximum received signal 0 dBm C/ICO C/I Cochannel 8) 13 dB C/I1ST Blocking at ＋10MHz 8) 7 dB C/I2ND Blocking at 10MHz 8) 16 dB C/I1M Image rejection 8) 30 dB 1) Max value determined by design and characterization testing. 2) Output frequency is 4MHz load of external clock pin is 5pF, Crystal is 4MHz. 3) Crystal is 4MHz. 4) Pin voltages are VSS or VDD. 5) Chip in power down, SPI_SCK frequency is 1MHz. 6) Operates in the 433, 868 and 915 MHz ISM band. 7) The crystal frequency may be chosen from 5 different values (4, 8, 12, 16, and 20MHz) 8) Data is Manchesterencoded before GFSK modulatio n. 9) Optimum load impedance, please see peripheral RF information. 10) Channel width and channel spacing is 200kHz. CURRENT CONSUMPTION Table 4 nRF905 current consumption. MODECRYSYALFREQ.[MHZ]OUTPUTCLOCKFREQ. [MHZ]TYPICAL CURRENTPowerDown 16OFF StandBy 4OFF 12181。42 177。A ISPI Supply current in SPI programming 3) 20 181。A Istbydclk Supply current in standby, uCLK enabled 2) 181。C) Table 3 nRF905 electrical specifications.SymbolParameter(condition)NotesMin.Typ.Max.Operating conditions VDD Supply voltage V TEMP Operating temperature 40 27 +85 176。C to +85186。2002．145～152.[3] :中國電力出版社,～20.[4]黃智偉，：電子工業(yè)出版社，～192.[5] :北京理工大學(xué)出版社,2001. 92～94.[6] 何立明．單片機(jī)高級教程——應(yīng)用與設(shè)計，北京：北京航天航空大學(xué)出版社，～173．[7]康華光，陳大欽. 電子技術(shù)基礎(chǔ)—數(shù)字部分. 北京：高等教育出版社，2000. 29～31.[8] 吳景狄．，2001(4):30～31．[9] 求是科技. :人民郵電出版社,～91.[10] 劉光潭．中外集成電路簡明速察手冊，上海：電子工業(yè)出版社，1991．45～46.[11]李忠杰．步進(jìn) 電動機(jī)應(yīng)用技術(shù)[M]．北京：機(jī)械 工業(yè) 出版社，～25.[12]劉瑞新，趙全利，趙建軍等．單片機(jī)原理及應(yīng)用教程，北京：機(jī)械工業(yè)出版社，2003年7月，157～164．[13] 李光飛，：北京航空航天大學(xué)出版社,2004. 13～20.[14]張俊謨. MCS51和80C51系列單片機(jī). 電子世界，2001年，第8期，30～38.[15] 李廣弟，朱月秀，王秀山．單片機(jī)基礎(chǔ)（修訂版），北京：北京航空航天大學(xué)出版社，2001年，16～17．[16]譚博學(xué)，苗匯靜等．集及成電路原理應(yīng)用．電子工業(yè)出版社，2003．29～31.[17]AT89C51，AT89C52說明書[S] ATMEL公司提供[18]ISD Inc．ISD data book．April 1998 [19]Wind River System Inc．VxWorks NetWork Programmer’sGuide[Z] [20]Single chip 433／868／915MHz Transceiver nRF905．Nordic VLSI ASA．2004．1．附錄一：各模塊原理圖附錄二：實驗箱PCB圖附錄三：英文資料Single chip 433/868/915 MHz Transceiver nRF905 FEATURES ? True single chip GFSK transceiver in a small 32pin package (32L QFN 5x5mm) ? ShockBurst? mode for low power operation ? Power supply range to V ? Multi channel operation – ETSI/FCC Compatible ? Channel switching time 650us ? Extremely low cost Bill of Material (BOM) ? No external SAW filter ? Adjustable output power up to 10dBm ? Carrier detect for listen before transmit protocols ? Data Ready signal when a valid data packet is received or transmitted ? Address Match for detection of ining packet ? Automatic retransmission of data packet ? Automatic CRC and preamble generation ? Low supply current (TX), typical 9mA 10dBm output power ? Low supply current (RX), typical APPLICATIONS ? Wireless data munication ? Alarm and security systems ? Home Automation ? Remote control ? Surveillance ? Automotive ? Telemetry ? Industrial sensors ? Keyless entry ? Toys GENERAL DESCRIPTION nRF905 is a singlechip radio transceiver for the 433/868/915 MHz ISM band. The transceiver consists of a fully integrated frequency synthesiser, receiver chain with demodulator, a power a