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 1, 31 July 2012 RDL2 UHF Multi Channel Wide Band FM Transceiver RDL2 is a half-duplex multi channel wideband FM transceiver in a BiM series footprint and operates on 433.05-434.79MHz European SRD band. This makes the RDL2 ideally suited to those low power applications where low cost multi-channel operation is required. Figure 1: RDL2-433-32 The RDL2 is a half duplex radio transceiver module for use in high-speed bi-directional data transfer applications at ranges up to 300metres. The small footprint of 23 x 33mm together with low power requirements of <28mA @ 5V enable convenient PCB installation. RDL2 allows operation on one of 5 pre-set frequencies in the 433MHz European licence exempt frequency band. These frequencies are non-overlapping and simultaneous operation of RDL2s in the same area on different channels will be possible. Units are supplied on 433.92MHz (Ch0) as default. Features Conforms to European EN 301 489-3 and ETSI EN 300 220-3 Data rates up to 32kbps High performance double superhet, PLL synthesizer Usable range up to 300 metres external, 75 metres in building SAW front end filter and full screening Low profile with small footprint 5 serial select wideband channels Available as RDL2T transmitter and RDL2R receiver for one-way communication Applications PDAs, organisers & laptops Handheld / portable terminals EPOS equipment, barcode scanners In-building environmental monitoring and control Remote data acquisition system, data logging Fleet management, vehicle data acquisition Technical Summary Operating frequency: 433.92MHz (default) Supply: regulated 5V @ 28mA TX, 24mA Rx Transmit power: +10dBm (10mW) Receiver sensitivity: -115dBm for 12dB SINAD Adjacent channel rejection: 65db @ ±320kHz Receiver Blocking: 80dB min. Size: 33 x 23 x 7mm Evaluation platforms: UNI-EVAL (RDL special) Radiometrix Ltd RDL2 Data Sheet page 1 Figure 2: RDL2 block diagram Radiometrix Ltd RDL2 Data Sheet page 2 side view (through can) side view (with can) 7 mm top view (without can) RF GND 1 Antenna 2 RF GND 3 4 5 6 No pin 7 8 9 18 17 16 15 14 13 12 11 10 0V Vcc ENABLE TXE TXD NC RXD SETUP 0V 23 mm recommended PCB hole size: 1.2 mm module footprint size: 25 x 32 mm pin pitch: 2.54 mm pins 4, 5, 6, 7, 8, 9 & 13 are not fitted 30.48 mm 33 mm Figure 3: RDL2 footprint (top view) Pin description Pin 18 17 16 15 14 13 12 11 Name 0V Vcc ENABLE TXE TXD NC RXD SETUP Function Ground 5V regulated power supply (4.75 - 5.25v) Pull low to enable module Pull low to transmit Transmit Data input ( 5v CMOS logic. No pullup) No Pin Receive Data output ( 5v CMOS logic output) Pull low to enter test/setup mode ( 5v CMOS logic. Pullup present sometimes) Ground 10 0V Notes: 1. Pinout is similar to a BiM2A. On RF connector end only pins 1,2,3 are present. 2. TXD / RXD are a direct connection to the radio hardware's baseband signals RF GND pin 1 & 3 RF Ground pin, internally connected to the module screen and pin 8, 9, 10 and 18 (0V). This pin should be connected to the RF return path (e.g. co-axial cable braid, main PCB ground plane, etc). RF pin 2 50Ω RF input/output from the antenna, it is DC isolated internally. (see antenna section for details). GND pin 8, 9, 10 and 18 Supply ground connection to ground plane and can. VCC pin 17 5V voltage regulator should be used to have a clean 5V supply to the module. A 4V regulator is used inside for radio circuitry. ENABLE pin 16 Active low enable pin. It has a 10kΩ pull-up to Vcc. It should be pulled Low to enable the module. Radiometrix Ltd RDL2 Data Sheet page 3 TXE pin 15 Active low enables transmitter. It has a 10kΩ pull-up to Vcc. (if used in RX only, tie this pin to +5v) TXD pin 14 This is a 5V CMOS logic level input. It can be directly interfaced to data output of a UART in a microcontroller. TXD does not have an internal pull-up. NC pin 13 There is no pin in this position. RXD pin 12 This is a 5V CMOS logic level output. It can be directly interfaced to data input of a UART in a microcontroller. SETUP pin 11 Pull low to enter test/setup mode. This is only sampled at power-up, and on tx>rx or rx>tx transitions. The pullup only enables at these times. Programming the RDL2 As supplied, the RDL2 is set to default channel zero. To change this preset, it is necessary to enter setup/program mode. The RDL2 is programmed through the same TXD / RXD pins that is used for sending/receiving data. An RS232 terminal emulator (such as Aterm or HyperTerminal) is an ideal tool. To connect to a true RS232 device, inverting RS232-CMOS level shifters must be used. Maxim MAX232 or equivalent are ideal, but simple NPN transistor switches with pull-ups often suffice. With typical microcontrollers and UARTs, direct connection is possible. To enter program mode the SETUP pin (pin 11) must be held low at turn-on, or during a change of TXE pin state. In this mode the radio link is disabled, but the TXD / RXD pins become a 9600 baud programming interface. (Bytes received are echoed back on the RXD pin). In 'setup' the unit will only respond to certain command strings: CHAN0 to CHAN4 <CR>: These commands select one of 5 preset channels A RDL2 will only communicate with a unit set to the same channel. Channel number is stored in volatile memory. On power-up the RDL2 reverts to the default in EEPROM (as supplied this is always Channel 0) SETPROGRAM <CR>: Writes the current address and current channel into EEPROM as the new default. A tilda character (~, ascii 126dec) sent by the unit indicates end of EEPROM write sequence (these commands are normally only used for factory diagnostics) NOTONE <CR>: Transmit unmodulated carrier LFTONE <CR>: Transmit carrier modulated with 8KHz squarewave HFTONE <CR>: Transmit carrier modulated with 16KHz squarewave # <CR>: Transmitter off A Carriage Return ‘<CR>’ (00Dhex) should be entered after each command sequence to execute it. Releasing the SETUP pin to high state returns the RDL2 to normal operation. Radiometrix Ltd RDL2 Data Sheet page 4 Condensed specifications Frequency Frequency stability Channel width Number of channels 433.92MHz – CHAN0 (default channel) 433.28MHz – CHAN1 433.60MHz – CHAN2 434.24MHz – CHAN3 434.56MHz – CHAN4 ±10kHz 320kHz 1 of 5, user programmed Transmitter Output power TX on switching time Modulation type FM peak deviation TX spurious 10dBm (10mW) ±1dB <5ms FSK +/-25KHz <-45dBm Receiver Sensitivity image spurious / adjacent channel Blocking LO re-radiation -115dBm for 12dB SINAD, 1KHz tone, at the analogue AF test -40dB -60dB -80dB min <-60dBm Interface Data rate Levels Supply Voltage Current Interfaces User RF Size Operating temperature Spurious radiations Radiometrix Ltd DC – 32kbps (NRZ) 5V CMOS 5V 28mA transmit 24mA receive / idle 9pin 0.1" pitch molex (pin 6 absent) 3pin 0.1" pitch molex 33 x 23 x 7mm ° ° ° ° -20 C to +70 C (Storage -30 C to +70 C) Compliant with ETSI EN 300 220-3 and EN 301 489-3 RDL2 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 combination connected directly to RF pin of the module. Optimum total length is 16cm (1/4 wave @ 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 dia.). The helical is a high Q antenna, trim the wire length or expand the coil for optimum 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 detuning. Feature A whip *** *** * * Ultimate performance Easy of design set-up Size Immunity proximity effects B helical ** ** *** ** C loop * * ** *** 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/ergonomic reasons thus a compromise may need to be reached. If an internal antenna must be used, try to keep it away from other metal components, particularly large ones like transformers, batteries and PCB tracks/earth plane. The space around the antenna is as important as the antenna itself. 0.5 mm enameled copper wire close wound on 3.2 mm diameter former RF 433 MHz = 24 turns A. Helical antenna Feed point 15% to 25% of total loop length RF-GND track width = 1mm 2 C2 C3 C4 C1 4 to 10 cm inside area RF B. Loop antenna 16.4cm C. Whip antenna wire, rod, PCB-track or a combination of these three RF 433 MHz = 16.4 cm total from RF pin. Figure 4: Antenna types Radiometrix Ltd RDL2 Data Sheet page 6 Radiometrix Ltd Hartcran House 231 Kenton Lane Harrow, Middlesex HA3 8RP ENGLAND Tel: +44 (0) 20 8909 9595 Fax: +44 (0) 20 8909 2233 [email protected] www.radiometrix.com Copyright notice This product data sheet is the original work and copyrighted property of Radiometrix Ltd. Reproduction in whole or in part must give clear acknowledgement to the copyright owner. Limitation of liability The information furnished by Radiometrix Ltd is believed 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 Ltd does not assume any liability arising from the application or use of any product or circuit described herein, nor for any infringements of patents or other rights of third parties which may result from the use 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 finished product on the market under the provisions of the R&TTE Directive. Equipment within the scope of the R&TTE Directive 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.ofcom.org.uk/ 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 [email protected] European Communications Office (ECO) Peblingehus Nansensgade 19 DK 1366 Copenhagen Tel. +45 33896300 Fax +45 33896330 [email protected] www.ero.dk