radiometrix ltd CLX2 data sheet page 1 features ?? conforms to en 300 220-2 and en 301 489-3 ?? saw front-end filter ?? small size ?? low cost ?? direct interface to microcontroller uart ?? serial modem baud rate at 19,200bps (half-duplex) applications ?? home/industrial automation ?? vehicle sensor monitoring ?? telemetry ?? data logging systems ?? security systems for home/industrial ?? in-building environmental monitoring and control ?? sports and performance monitoring technical summary ?? operating frequency: 433.92mhz (default) ?? modulation: 34.5kbps nrz fsk ?? uart interface: 19,200bps, 8 data bits , none parity, no ne flow control ?? supply: 3.3v at 23ma transmit, 13ma receive and <2ma standby ?? transmit power: +3dbm (2mw) ?? receiver sensitivity: -95dbm (for 1% ber) ?? 32 byte data buffer ?? 40 x 14 x 5mm 19200 baud modem transceiver the CLX2s a 19,200baud half-duplex serial radio modem module operating on licence- exempt european 433.05-434.79mhz srd band. CLX2 is an intermediate level oem radio modem which is in between a raw fsk radio module like bim2g and a sophisticated oem radio modem like r pm2a. it takes care of preamble, frame synchronisation and error checking. hartcran house, 231 kenton lane, harrow, middlesex, ha3 8rp, england tel: +44 (0) 20 8909 9595, fax: +44 (0) 20 8909 2233, www.radiometrix.com issue a , 10 a p ril 2012 CLX2 preliminary figure 1: CLX2 - 433 - 1 9
radiometrix ltd CLX2 data sheet page 2 figure 2: CLX2 block diagram
radiometrix ltd CLX2 data sheet page 3 the radio / datastream interface a 32 byte software fifo is implemented in both the transmit and receive code. at the transmit end this is used to allow for the transmitter start up time (about 4ms), while on rece ive it buffers arriving packets to the constant output data rate. all timi ng and data formatting tasks are handled by the software. the user need not worry about keying the tr ansmitter before sending data: the link is entirely transparent. for transmission across the radio link data is formatte d into packets, each comp rising 6 bytes of data, a preamble sequence, a sync code and a checksum. if le ss than 6 bytes are in the transmit end fifo then a packet is still sent, but idle codes replaces th e unused bytes. when the transmit end fifo is completely emptied, then th e transmitter is keyed off . figure 3: CLX2 footprint (top view) pin description pin name function 1 gnd ground 2 rxd received data output at 3v uart (inverted rs232) level 3 txd transmit data input at 3v uart (inverted rs232) level [no pull- up] 4 /txon /rxoff /txon active low transmitter on indicator output [transmit mode] /rxoff active low receiver hot standby input [receive mode] open drain, 50k ? internal pull-up 5 vdd 3.3v dc (externally regulated power supply) rssi received signal strength indicator output (an optional pad for wire connection) 1a rf rf in/out (50 ? impedance) 2a rfgnd rf ground notes : 1. txd has no internal pull-up. if the unit is used in receive only mode, tie this pin to vcc 2. vdd must be a clean 3.3v dc regulated supply 3. the status pin. in transmit, this pin pulls lo w if the device is transmitting a data packet. on receive it floats high. if pulled low in re ceive, the unit goes into hot standby (<2ma) in standby the unit does not receive, but will go in to transmit if valid data is presented to txd. 4. txd / rxd are inverted rs232 at 3v cmos leve ls. to connect to a true rs232 device, inverting level shifters must be used (e .g. max232 type are ideal, but simple npn transistor switches with pull-ups often suffice). with typical micro controllers and uarts, direct connection is possible. 5. the CLX2 provides a half duplex link, but provided no two devices attempt to transmit at one time then no further restrictions on data tran smission need be made, as all transmit timing, valid data identification and datastream buffe ring is conducted by the unit. there is no 'transmit enable' pin. synchronisation and fram ing words in the packet prevent the receiver outputting garbage in the absence of signal or presence of interference. 6. a 2.2k ? resistance is present from rf pi n 1a to ground for esd protection
radiometrix ltd CLX2 data sheet page 4 condensed specifications frequency 433.92mhz frequency stability 10khz channel width 400khz number of channels 1 supply voltage 3.3v dc current 23ma transmit 13ma receive/ <2ma standby operating temperature -20 c to +55 c (storage -30 c to +70 c) spurious radiations compliant with etsi en 300 220-2 and en 301 489-3 interfaces user 5pin 0.1" pitch molex (pin 6 absent) rf 2pin 0.1" pitch molex size 40 x 14 x 5mm transmitter output power 2mw 1db tx on switching time <4ms modulation type 35kbps nrz fsk fm peak deviation +/-90khz (nominal) tx spurious <-36dbm receiver sensitivity -95dbm (for 0.1% data error) blocking -50db (1mhz) local oscillator re-radiation <-57dbm interface data rate 19,200baud, half duplex format 1 start bit, 8 data bits, no parity, 1 stop bit levels 3v cmos (inverted rs232 ?0?=0v, ?1?=3v) buffers 32 byte fifo flow control none initial start up 10ms from power on
radiometrix ltd CLX2 data sheet page 5 antenna requirements three types of integral antenna are recommended and approved for use with the module: a) whip this is a wire, rod ,pcb track or combinat ion connected directly to rf pin of the module. optimum total length is 16cm (1/4 wa ve @ 433mhz). keep the open circuit (hot) end well away from metal components to prevent serious de-tuning. whips are ground plane sensitive and will benefit from internal 1/4 wave earthed radial(s) if the product is small and plastic cased b) helical wire coil, connected directly to rf pin, open circuit at other end. this antenna is very efficient given it?s small size (20mm x 4mm di a.). the helical is a high q antenna, trim the wire length or expand the coil for opti mum results. the helical de-tunes badly with proximity to other conductive objects. c) loop a loop of pcb track tuned by a fixed or variable capacitor to ground at the 'hot' end and fed from rf pin at a point 20% from the ground end. loops have high immunity to proximity de-tuning. a b c whip helical loop ultimate performance *** ** * easy of design set-up *** ** * size * *** ** immunity proximity effects * ** *** the antenna choice and position directly controls the system range. keep it clear of other metal in the system, particularly the 'hot' end. the best position by far, is sticking out the top of the product. this is often not desirable for practical/er gonomic reasons thus a compromise may need to be reached. if an internal antenna must be used, try to keep it aw ay from other metal components, particularly large ones like transformers, batteries and pcb tracks/ear th plane. the space around the antenna is as important as the antenna itself. a. helical antenna b. loop antenna rf c1 c2 c4 c3 rf-gnd c. whip antenna 16.4cm rf 0.5 mm enameled copper wire close wound on 3.2 mm diameter former 433 mhz = 24 turns feed point 15% to 25% of total loop length track width = 1mm 4 to 10 cm inside area wire, rod, pcb-track or a combination of these three 433 mhz = 16.4 cm total from rf pin. 2 rf fi g ure 4: antenna t yp es
radiometrix ltd hartcran house 231 kenton lane harrow, middlesex ha3 8rp england tel: +44 (0) 20 8909 9595 fax: +44 (0) 20 8909 2233 sales@radiometrix.com www.radiometrix.com copyright notice this product data sheet is the orig inal work and copyrighted property of radiometrix ltd. reproduction in whole or in part must give clear a cknowledgement to the copyright owner. limitation of liability the information furnished by radiometrix ltd is be lieved to be accurate and reliable. radiometrix ltd reserves the right to make changes or improvements in the design, specification or manufacture of its subassembly products without notice. radiometrix lt d does not assume any liability arising from the application or use of any product or circuit described herein, nor for any infri ngements of patents or other rights of third parties which may result from the us e of its products. this data sheet neither states nor implies warranty of any kind, including fitness for any particular application. these radio devices may be subject to radio interference and may not function as intended if interference is present. we do not recommend their use for life critical applications. the intrastat commodity code for all our modules is: 8542 6000 r&tte directive after 7 april 2001 the manufacturer can only place fini shed product on the market under the provisions of the r&tte directive. equipment within the scope of the r&tte di rective may demonstrate compliance to the essential requirements specified in article 3 of the directive, as appropriate to the particular equipment. further details are available on the office of communications (ofcom) web site: http://www.erodocdb.dk/docs/doc98/official/pdf/rec7003e.pdf information requests ofcom riverside house 2a southwark bridge road london se1 9ha tel: +44 (0)300 123 3333 or 020 7981 3040 fax: +44 (0)20 7981 3333 information.requests@ofcom.org.uk european communications office (eco) peblingehus nansensgade 19 dk 1366 copenhagen tel. +45 33896300 fax +45 33896330 ero@ero.dk www.ero.dk
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