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WT21 evaluation kit data sheet friday, 05 february 2010 version 1.3
copyright ? 2000-2010 bl uegiga technologies all rights reserved. bluegiga technologies assumes no responsibility for any errors which may appear in this manual. furthermore, bluegiga technologies reserves the right to alter the hardware, software, and/or specifications detailed here at any time without notice and does not make any commitment to update the information contained here. bluegiga?s products are not authorized fo r use as critical components in life support devices or systems. the wrap is a registered trademark of bluegiga technologies the bluetooth trademark is owned by the bluetooth sig inc., usa and is licensed to bluegiga technologies. all other trademarks listed herein are owned by their respective owners. bluegiga t echnologies oy
version history version comment 0.1 first draft 1.0 first release 1.1 added images 1.2 bootstrap added 1.3 pin out numbers fixed bluegiga t echnologies oy
table of contents 1 ................................................................................................................................................... 5 introduction 2 ............................................................................................................................................ 6 physical outlook 3 ................................................................................................................................................... 7 schematics 4 ............................................................................................................................... ..................... 10 assembly 5 ............................................................................................................................... .......................... 11 layout 6 ............................................................................................................................... ..................... 12 interfaces 6.1 ............................................................................................................. 12 powering the evaluation board 6.2 ............................................................................................................................... ..................... 12 uart 6.3 ..................................................................................................................... 12 host selection dip switch 6.3.1 .............................................................................................................. 12 uart protocol selection 6.3.2 .......................................................................................................... 13 uart baudrate negotation 6.3.3 .................................................................................................................... 13 loading the ps keys 6.4 ............................................................................................................................... .......... 14 spi interface 6.5 ........................................................................................................................ 14 sdio and pio interface 6.6 .......................................................................................................... 14 pcm codec and audio interface 7 ............................................................................................................................... ...... 15 weee compliance 8 ............................................................................................................................... ..... 16 contact information bluegiga t echnologies oy
1 introduction f eatures ? evaluation kit for wt32 bluetooth audio module containing o rs-232 serial interface (230400bps) o usb interface for power supply o spi for upgrading the firmware and parameters o reset button o pcm codec (oki msm7702-01) o 2 x 3,5mm audio jacks for line in and line out o 24 pin i/o interface (pio1 ? pio9, uart, sdio, pcm, gnd, 3v3, ena) o dip switches for host interface configuration o current measurement point ? host controller interface t arget a pplications WT21 evaluation kit is meant for evaluation and development of WT21 bluetooth module or prototyping and piloting bluetooth systems utilizing WT21 module. e lectrical functionality please, refer to the latest WT21 data sheet for information about WT21 bluetooth module. the physical outlook, schematics, assembly and the pin configuratio ns of the interfaces of WT21 evaluation kit are described in this document. s oftware functionality wt32 evaluation kit is delivered with host controller interface (hci) firmware, so WT21 only implements the lowest levels of bluetooth stack. wt 21 always requires a host system that implements the upper layers of bluetooth stack and at least one bluetooth profile. bluegiga t echnologies oy page 5 of 16
bluegiga technologies oy page 6 of 16 2 physical outlook figure 1: WT21 front view figure 2: WT21 back view
bluegiga t echnologies oy 3 schematics figure 3: ekWT21 schematic (1/3) page 7 of 16
bluegiga t echnologies oy figure 4: ekWT21 schematic (2/3) page 8 of 16
bluegiga t echnologies oy figure 5: ekWT21 schematic (3/3) page 9 of 16
bluegiga t echnologies oy 4 assembly figure 6: assembly drawing of ekWT21 page 10 of 1 6
bluegiga technologies oy page 11 of 16 figure 8: bottom layer layout figure 7: to p layer layout 5 layout
6 interfaces 6.1 powering the evaluation board the board can be powered either through a usb conne ctor j10 or using a laboratory power supply through pin header j4. ldo tps79933ddct is used to regulate 3.3v supply voltage for the module (vreg_in and vdd_pads). maximum input voltage for the regulator is 6.5v. enable pins of the in ternal regulators of the module (vreg_ena) are tight to 3.3v supply through zero ohm resistor r1. 6.2 uart uart interface of the module is available in the pi n header j3. when uart is being used through the pin header the rs232 transceiver u2 should be switched to high impedance using sw11. when using rs232 through j5 the transceiver should be enabled with sw11. the maximum baud rate of the transceiver in the evaluation board is 235kbps. 6.3 host selection dip switch dip switch sw1 is used for the host selection as described below. the mcu of WT21 selects the uart/sdi o interfaces by reading pio[4] at boot-time. when pio[4] is high, the sdio interface is enabled; when pio[4] is low, the uart is enabled. if in uart mode, the mcu selects t he uart transfer protoc ol automatically using the unused sdio pins shown in table 1. table 1: sdio_clk and sdio_cmd transfer protocols 6.3.1 uart protocol selection at bootup the module looks at pio4 to determine whether it should use uart or sdio/cspi. if pio4 is pulled low then uart will be used. it then checks sdio_clk and sdio_cmd pins to determine which mode it should use for receiving initial pskeys over uart. note : when the switch on the eval board is c onducting (marked by "on") then the pin is pulled low which is marked by 0. to use the h4 uart protocol for configuring the wt 21 the pio4 should be pulled low, the sdio_clk should be pulled low and sdio_cmd must be pulled high. note that by default there is a weak pull-up for these pins so if nothing is connected to them, they will be pulled high. bluegiga t echnologies oy page 12 of 1 6
6.3.2 uart baudrate negotation when pio4, clk and cmd are all pulled low, bcsp over uart is selected. the speed for this initial communication should be between 57600bps and 115200bps and must use even parity. since the WT21 doesn't know its internal clock frequenc y nor the baud rate it should communicate at, a form of baud rate auto-negotiation is implemented on the modul e. the host needs to send some data packets so that the WT21 can assess the baud rate the host uses. any seemingly non-uniform data can be used but for bcsp sending link establishment packets is the natural choice. once the WT21 has received enough samples it w ill start communicating back to the host by replying to the link establishment messages. since the h4 doesn't have any link protocol, repeated queries for some known value can be used. once the host has started receiving replies for the queries, it can be assumed that that the baud rate has been established. note: the number of packets the WT21 will need for assessing the baud rate is dependent on the host's uart hardware. with poor quality uarts the auto-negotiation may fail, which means the WT21 will use an incorrect baud rate to communicate back. the host will see this as packets of garbage, i.e. full of crc erro rs and checksum errors when using bcsp. to restart the negotiati on the host will need to reset the WT21. the host should have so me way to power cycle the WT21 to restart the baud rate negotiation, either by controlling the rese t pin or directly the module's vcc. 6.3.3 loading the ps keys once a communications link has been established, bccm d packets are used to load ps keys. at least the following ps keys need to be set: key address v alue description &0001 00dd eeff 00cc aabb bluetooth address (aa:bb:cc:dd:ee:ff) &01be 01d8 uart baud rate (01d8 = 115200) &01fe 6590 chrystal frequency. do not modify. &025d 0001 vm disable. do not modify. &01f9 0001 host interface, (0001 = bcsp) for the host interface the follo wing protocols are supported: ? bcsp 0001 ? h4 0003 ? h5 0006 ? h4ds 0007 to activate the changes the command for warm reset is sent to the WT21. after this the module will immediately reboot using the configured settings and thus switch to the specified baud rate. bluegiga t echnologies oy page 13 of 1 6
6.4 spi interface spi is available in the pin header j1. following table shows the connections in the pin header. 3.3v is an output from the evaluation board and it is used to power the on board installation kit delivered with the kit. pin name no. i/o description miso 1 o miso 3.3 v 2 power 3.3 v power supply input clk 3 i clk mosi 4 i mosi csb 5 i csb gnd 6 gnd gnd table 2: spi interface pin description 6.5 sdio and pio interface all sdio and pio connections are available in the pin header j3. 6.6 pcm codec and audio interface the evaluation board uses msm7702 pcm codec by ok i semiconductor. ps settings for the codec are as follows: o pcm_dataformat 0200 o pcm_config32 180000c0 o host_io_map_sco_pcm true headset can be connected to 3.5mm jack connectors j6 and j7. bluegiga t echnologies oy page 14 of 1 6
7 weee compliance the crossed-out wheeled bin means that within the european union the product must be taken to separate collection at the product end-of-life. do not dispose of these products as unsorted municipal waste. bluegiga t echnologies oy page 15 of 1 6
bluegiga technologies oy page 16 of 16 8 contact information sales: sales@bluegiga.com technical support: support@bluegiga.com http://www.bluegiga.com/techforum/ orders : orders@bluegiga.com head office / finland: phone: +358-9-4355 060 fax: +358-9-4355 0660 street address: sinikalliontie 5a 02630 espoo finland postal address: p.o. box 120 02631 espoo finland sales office / usa: phone: (781) 556-1039 bluegiga technologies, inc. 99 derby street, suite 200 hingham, ma 02043

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