Laird BTM521 User Manual
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Laird BTM521 User Manual

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BTM520/521
DATA MODULE
USER MANUAL
Innovative Technology
for a Connected World

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Summary of Contents for Laird BTM521

  • Page 1 BTM520/521 DATA MODULE USER MANUAL Innovative Technology for a Connected World...
  • Page 2 Recommended PCB Footprint .... 43 Glossary of Terms ....... 12 Diagrams ..........44 AT Command Set ......13 Assumptions ........13 Ordering Information ....47 Product Part Numbers ......47 Commands ........13 General Comments ......47 General AT Commands ..... 13 www.lairdtech.com Laird Technologies...

  • Page 3: Overview

    The BTM520 and BTM521 are the most advanced low power, multimedia Bluetooth KEY FEATURES modules on the market. They have been designed by Laird Technologies to meet the needs of developers who require the ultimate Bluetooth audio performance and flexibility, along with fast time to market.
  • Page 4 • Integrated audio amplifiers for driving 16Ω speakers • Comprehensive AT interface for simple programming • Bluetooth END Product Qualified • Compact Size • Class 1 output – 8dBm (typical) • Low power operation • Wi-Fi Coexistence Hardware Support www.lairdtech.com Laird Technologies...

  • Page 5: Specifications

    Adaptive Frequency Hopping Max Transmit Power +8 dBm (typical) @ antenna pad – BTM520 +10 dBmi (typical) from integrated antenna – BTM521 (provisional) Min Transmit Power -27 dBm @ antenna pad – BTM520 -27 dBmi from integrated antenna – BTM521 (provisional)
  • Page 6 Storage Temperature -40°C to +85°C Approvals Bluetooth Qualified as an END product ® Meets FCC requirements Modular Approval (Integrated Antenna option – BTM521) CE & R&TTE Meets CE and R&TTE requirements Miscellaneous Lead free Lead-free and RoHS compliant Warranty 12 Months...
  • Page 7 Microphone, channel B- (right) – Note 4 MIC_AN_C Microphone, channel B+ (right) – Note 4 Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused Unused www.lairdtech.com Laird Technologies...
  • Page 8 Main regulator enable – pull high for correct operation UART_RTS Request to Send O/P VUSB UART_CTS Clear to Send I/P VUSB UART_TX Transmit data O/P VUSB UART_RX Receive data I/P VUSB Reset Module reset I/P (active low) – Note 1 VPADS www.lairdtech.com Laird Technologies...

  • Page 9: Operating Parameters

    VDD_PADS+0.3 -0.3 0.25VDD_PADS Output Voltage Levels (Iout = -4mA) 0.75VDD_PADS VDD_PADS (Iout = 4mA) 0.125 LOGIC LEVELS (VUSB – USB TERMINALS D+, D-) Input Voltage Levels 0.7VDD_USB 0.3VDD_USB Output Voltage Levels (to correctly terminated USB cable) VDD_USB www.lairdtech.com Laird Technologies...

  • Page 10: Notes

    -40dBV to -60dBV. When operating in line input mode, the input can be connected directly to the module input pins in either single or double ended configuration as follows: Single ended Double ended 10 www.lairdtech.com Laird Technologies...

  • Page 11: Configuring The Btm520/521

    Just like telephony modems, Laird Technologies’ devices powers up in an unconnected state and will only respond via the serial interface. In this state the device will not even respond to Bluetooth Inquiries. Then, just like controlling a modem, the host can issue AT commands which map to various Bluetooth activities.

  • Page 12: Glossary Of Terms

    PBAP Phone Book Access Profile Pulse Width Modulation Sxxx S-Register No. xxx Sub Band Codec Serial Port Profile To Be Determined UART Universal Asynchronous Receiver / Transmitter PASS THROUGH Command UNIT INFO Command SUBUNIT INFO Command 12 www.lairdtech.com Laird Technologies...

  • Page 13: At Command Set

    Response: <cr,lf>CALL LIMIT <cr,lf>NO CARRIER<cr,lf> In that case, issuing an ATZ to reset the device will reset the count to 0 and more connections are possible. 13 www.lairdtech.com Laird Technologies...
  • Page 14 Enable echo. All other values of n will generate an error. Response: <cr,lf>OK<cr,lf> Response: <cr,lf>ERROR nn<cr,lf> 7. ATH {Drop Connection} Drop an existing connection or reject an incoming connection indicated by unsolicited RING messages. Response: <cr,lf>NO CARRIER<cr,lf> 14 www.lairdtech.com Laird Technologies...
  • Page 15 0..2 Set A2DP role: 0 is feature not set 1 is A2DP Sink (default) 2 is A2DP Source S301 0..2 Set AVRCP role: 0 is feature disabled 1 is Control (CT) (default) 2 is Target (TG) 15 www.lairdtech.com Laird Technologies...
  • Page 16 Disable legacy (pre-BT2.1) Pairing: 0 – legacy pairing enabled 1 – legacy pairing disabled S324 1..255 Secure Simple Pairing timeout in s This value must be at least 90 in order to meet the recommendation of BT2.1 specification 16 www.lairdtech.com Laird Technologies...
  • Page 17 MUST be set to 0, otherwise a deassertion of DSR will be seen as a request to drop the Bluetooth connection. ® This register affects S Register 536 – see details of 536 17 www.lairdtech.com Laird Technologies...
  • Page 18 This value is rounded down to the nearest 100ms S530 1000 100..15000 Reconnect delay when configured as master in pure-cable-replacement mode. This value is rounded down to the nearest 100ms. See S Register 505 and 543 also. 18 www.lairdtech.com Laird Technologies...
  • Page 19 (as if an explicit AT+BTR command was entered). See S Register 505 and 530 also 19 www.lairdtech.com Laird Technologies...
  • Page 20 If the nibble in 552 is 0, then the relevant pin is an input. Each nibble can take the following value:- 0 Always deassert 1 Always assert 2 Assert if RING is being sent to the host 20 www.lairdtech.com Laird Technologies...
  • Page 21 After a disconnection, there will be a cold reset S589 0..F Codec output gain S590 0..3 Codec input gain S591 0..1FF Default GPIO output states when not in a connection. This is used when virtual digital i/o cable replacement mode is in operation 21 www.lairdtech.com Laird Technologies...

  • Page 22: 2 Www.lairdtech.com

    <cr,lf>OK<cr,lf> and OK is returned after the RESET 12. AT&W {Write S Registers to Non-volatile Memory} Writes current S Register values to non-volatile memory so that they are retained over a power cycle. Response: <cr,lf>OK<cr,lf> Response: <cr,lf>ERROR nn<cr,lf> 22 www.lairdtech.com Laird Technologies...
  • Page 23 CONFIGURING 13. ATIn {Information} THE BTM520/521 This will return the following information about the Laird Technologies device. The product name/variant. The CSR firmware build number. The Laird Technologies firmware build number. For internal use only. The Laird Technologies firmware revision.

  • Page 24: General Bluetooth ® Control

    <cr,lf>ERROR nn<cr,lf> General Bluetooth Control 1. AT+BTAn {Control Audio Channel} Once a Bluetooth connection is active, and assuming the peer device is also a Laird Technologies device, this command is used to start/stop a SCO channel to transfer audio between the two peer devices. +BTA0 Switch off the channel.
  • Page 25 This is an 11 bit field used as a mask to define the Major Service Class, as per Table 1.2 in “Bluetooth Assigned Number” Laird Technologies devices do not map to any predefined Major Service Class or Major Device Class and so the default devclass as shipped is 001F00, which means no Major Service Class and “Unclassified”...
  • Page 26 AT+BTI commands will always return it. Response: <cr,lf>ERROR 27<cr,lf> 11. AT+BTIV<devclass> {Inquire} As per AT+BTI but the response includes the device class code for all inquiry responses. Please refer to the ‘ERROR RESPONSE’ note in the description for AT+BTI<devclass>. Response: <cr,lf>12346789012,123456 <cr,lf>12345678914,123456 <cr,lf>OK<cr,lf> 26 www.lairdtech.com Laird Technologies...
  • Page 27 The friendly name strings are in UTF-8 format as per the Bluetooth specification. Response: <cr,lf>12346789012,123456,”TDK SYSTEMS AT DONGLE 1” <cr,lf>12345678914,123456, “TDK SYSTEMS RS232” <cr,lf>OK<cr,lf> Note: Many releases of firmware will return the product name as LAIRD, e.g. Response: <cr,lf>12346789012,123456,”TDK SYSTEMS AT DONGLE 1” <cr,lf>12345678914,123456, “TDK SYSTEMS RS232” <cr,lf>OK<cr,lf>...
  • Page 28 This command is used to display the peer address stored in non-volatile memory, used to put the device in pure cable replacement mode. Response: <cr,lf>12346789012 <cr,lf>OK<cr,lf> If the location is empty the response is as follows. Response: <cr,lf>00000000000 <cr,lf>OK<cr,lf> 28 www.lairdtech.com Laird Technologies...
  • Page 29 If the cache is empty the response is as follows. Response: <cr,lf>OK<cr,lf> 28. AT+BTX {Disable Page/Inquiry Scanning} Disable page/inquiry scanning. This means it will not accept incoming connections or inquiry requests. In fact this negates the effect of AT+BTQ, AT+BTG and AT+BTP commands. Response: <cr,lf>OK<cr,lf> 29 www.lairdtech.com Laird Technologies...

  • Page 30: Hardware Unit Control

    Instead, the current gain level is cached and can be retrieved by “AT+G(I|O)?”. There are 2 further commands to restore the cached gain level from S589/S590 (“AT+G(I|O)R”) and to save the currently cached gain level to S589/S590 (“AT+G(I|O)S”). 30 www.lairdtech.com Laird Technologies...
  • Page 31 Decrement current input AT+GID Error 58 may appear if minimum gain gain level level reached Query current input gain level AT+GI? Restore current input gain AT+GIR level from S590 Save current input gain AT+GIS level to S590 31 www.lairdtech.com Laird Technologies...

  • Page 32: Bluetooth ® Profiles

    Bluetooth Version of the paging device. After an A2DP connection has been established, the module remains in AT Command mode. S Register 531 is ignored for A2DP connections. 32 www.lairdtech.com Laird Technologies...
  • Page 33 Remote control commands are passed to a subunit with the “PASS THROUGH” command. A BT-MM+ Module, configured as target will support one PANEL subunit. 3.1 AVRCP - Control (CT) This section describes AT Commands and S registers used when BT-MM+ is configured as an AVRCP Controller (S301=1). 33 www.lairdtech.com Laird Technologies...
  • Page 34 Send a Subunit Info request to a connected AVRCP target. Response: <cr,lf>OK<cr,lf> (immediately) And: <cr,lf>AVSR <page > <pagedata > <cr,lf> (after command completion) <page > requested page [0..31] <pagedata > : 1st word of requested page 34 www.lairdtech.com Laird Technologies...
  • Page 35 It is mandatory to respond to a SUBUNIT INFO command if configured as AVRCP target. Required response parameters are Subunit type and MaxSubUnitId. Subunit type will always be returned as 0x09 (Panel). MaxSubUnitId will always be returned as 0x00 (only one subunit exists, which is panel) 35 www.lairdtech.com Laird Technologies...
  • Page 36 ‘1’ Button released Response on command completion: “AVPTC n <operation_id > <state>” Respond to incoming Pass AT+AVR<avrc_response_type > <avrc_response_type >: see Table 3 10 Through command If S 310 == 1, response from host is not required. 36 www.lairdtech.com Laird Technologies...
  • Page 37 Stop 0x45 STOP Pause 0x46 PAUSE Record 0x47 Rewind 0x48 REWIND Fast forward 0x49 FFORWARD Eject 0x4A Forward 0x4B FORWARD Backward 0x4C BACKWARD Angle 0x50 Sub picture 0x51 0x71 0x72 0x73 0x74 0x75 Vendor unique 0x7e 37 www.lairdtech.com Laird Technologies...
  • Page 38 ‘1’ – Button released AVPTC n <operation_id > <state> Confirmation of AT+AVC (Control Command Request) n: ‘0’ – successful ‘1’ – timeout ‘2’ – not successful, other than timeout RING 0123456789012 110E Indication of AVRCP control connection request 38 www.lairdtech.com Laird Technologies...

  • Page 39: Secure Simple Pairing

    (for example on BISM2 the command “AT+BTW<BdAddr>” would be used). After successful pairing, the connection can be initiated by the legacy device (for example on BISM2 the “ATD<BdAddr>” command would be used). 39 www.lairdtech.com Laird Technologies...

  • Page 40: Miscellaneous

    = “NO CARRIER 110D”; If no AVRCP connection has existed: response = “NO CARRIER” Disconnect all profiles ATH* Response = “NO CARRIER <ProfileUUID>” for each previously connected profile 3. Production Info String A string with production information can be retrieved by “ATI200”. 40 www.lairdtech.com Laird Technologies...

  • Page 41: Appendix

    Device Class could not be stored Invalid Device Class Code Invalid Bluetooth Address Could not set Service or Friendly name PS Store Write PS Store Read Not Idle Incorrect Mode Already Scanning Pairing is already in progress Not USED 41 www.lairdtech.com Laird Technologies...
  • Page 42 No A2DP or AVRCP connection currently incoming Invalid operation ID (AVRCP) Wrong AVRCP role Command disabled by S-Register 310 Production info string does not exist Audio resource error Invalid UUID Maximum gain level reached Minimum gain level reached 42 www.lairdtech.com Laird Technologies...

  • Page 43: Mechanical Drawings

    Global length of pad to edge of board Units RECOMMENDED PCB FOOTPRINT MODULE OUTLINE (See note 2) Pad Width 0.7 Typ 10.6 Pad Length 1.65 Typ RF OUT (See Note 1) (all dimensions in mm) pin pitch 1x14 21.2 43 www.lairdtech.com Laird Technologies...
  • Page 44 BTM520/521 Bluetooth Multimedia Plus Module ® MECHANICAL DRAWINGS 44 www.lairdtech.com Laird Technologies...
  • Page 45 BTM520/521 Bluetooth Multimedia Plus Module ® MECHANICAL DRAWINGS 45 www.lairdtech.com Laird Technologies...
  • Page 46 BTM520/521 Bluetooth Multimedia Plus Module ® MECHANICAL DRAWINGS 46 www.lairdtech.com Laird Technologies...

  • Page 47: Ordering Information

    Development Board with BTM521 soldered in place GENERAL COMMENTS This is a preliminary user manual. Please check with Laird Technologies for the latest information before commencing a design. If in doubt, ask. Refer to the schematic BTV-R-003.pdf for the Development Kit for examples of typical pin connections.
  • Page 48 Laird Technologies will not be liable for, any damage or failure caused by misuse, abuse, acts of God, accidents, electrical irregularity, or other causes beyond Laird Technologies’ control, or claim by other than the original purchaser. In no event shall Laird Technologies be responsible or liable for any damages arising: From the use of product; From the loss of use, revenue or profit of the product; or As a result of any event, circumstance, action, or abuse beyond the control of Laird Technologies, whether such damages be direct, indirect, consequential, special or otherwise and whether such damages are incurred by the person to whom this warranty extends or third party.

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