BTM520/521 DATA MODULE USER MANUAL www.lairdtech.
BTM520/521 Bluetooth® Multimedia Plus Module TABLE OF CONTENTS CONTENTS BTM520/521 Bluetooth® Module ...3 Overview . ............................................. 3 BTM520/521 Key Features . .................. 3 Specifications .................................5 Detailed Specifications .......................... 5 Pin Out . ................................................ 6 Operating Parameters ....................9 Voltage Specifications ........................... 9 Notes ............................
BTM520/521 Bluetooth® Multimedia Plus Module OVERVIEW AND KEY FEATURES The BTM520 and BTM521 are the most advanced low power, multimedia Bluetooth 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. The modules include everything needed for a fully qualified and functional Bluetooth multimedia application.
BTM520/521 Bluetooth® Multimedia Plus Module OVERVIEW AND KEY FEATURES 4 www.lairdtech.com FEATURES • Fully featured Bluetooth multimedia module • Supports CSR Road Tunes and Blue Tunes applications • Bluetooth v2.
BTM520/521 Bluetooth® Multimedia Plus Module SPECIFICATIONS CATEGORIES FEATURE IMPLEMENTATION Wireless Specification Standards Supported Bluetooth® v2.1 + EDR Transmit Class Class 1 Frequency 2.402 – 2.
BTM520/521 Bluetooth® Multimedia Plus Module SPECIFICATIONS CATEGORIES FEATURE IMPLEMENTATION Command Interface AT Instruction set Comprehensive control of connection and module operation, including extensions for Audio control. Direct mapping of GPIO to audio functions, e.g. Play, Volume, etc.
BTM520/521 Bluetooth® Multimedia Plus Module SPECIFICATIONS 7 www.lairdtech.
BTM520/521 Bluetooth® Multimedia Plus Module SPECIFICATIONS PiN Out (continued) Pin Signal 55 56 57 58 59 60 61 62 Unused Unused Unused PIO3 / USB_VSENSE PIO14 / CSB AUX_DAC PIO4 PIO5 / BT_STATE / BT_PRORITY PIO7 / RF_ACTIVE PIO15 PIO12 / SCL GND AIO1 PIO10 / DSR PIO11 / DTR AIO0 PIO9 / DCD PIO13 / SDA PIO8 / RI PIO6 / WLAN_ACTIVE GND USB_DUSB_D+ PIO2 / USB_PULL_UP VDD_USB VREGENABLE_H GND UART_RTS UART_CTS UART_TX UART_RX Reset 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86
BTM520/521 Bluetooth® Multimedia Plus Module OPERATING PARAMETERS Operating Parameters Recommended Operating Conditions Operating Condition Min Max VDD_USB (USB compatibility not required) 1.7 3.6 VDD_USB (USB compatibility required) 3.1 3.6 VDD_IO 1.7 3.6 VDD_PADS 1.7 3.6 VDD_IN 3.0 3.3 Voltage Specifications Logic Levels (VUSB) Input Voltage Levels Min Typ Max Vih 0.625VDD_USB VDD_USB+0.3 Vil -0.3 0.25VDD_USB Voh (Iout = -4mA) 0.75VDD_USB VDD_USB Vol (Iout = 4mA) 0 0.
BTM520/521 Bluetooth® Multimedia Plus Module OPERATING PARAMETERS Note: 1. 2. Reset input is active low. Input is pulled up to VDD_PADS via 22k. Minimum reset pulse width is 5ms. LED drive pins are open drain outputs and hence the external circuit to the right should be used. The voltage on the module pad should be maintained below 0.5V in which case the Ron of the FET is around 20Ω.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 Introduction This document describes the protocol used to control and configure the BT-MM+ Bluetooth device. The AT commands described in the document apply to firmware releases from V14.0.9 onwards. The protocol is similar to the industry standard Hayes AT protocol used in telephony modems which is appropriate for cable replacement scenarios, as both types of devices are connection oriented.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 12 www.lairdtech.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 AT Command Set Assumptions 1. All commands are terminated by the carriage return character 0x0D, which is represented by the string in descriptions below this, cannot be changed. 2. All responses from the device have carriage return and linefeed characters preceding and appending the response. These dual character sequences have the values 0x0D and 0x0A respectively and shall be represented by the string . 3.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 The following RFCOMM based UUIDs are defined in the Bluetooth Specification:Profile Name UUID Serial Port 0x1101 LAN Access Using PPP 0x1102 Dialup Networking 0x1103 IrMC Sync 0x1104 OBEX Object Push 0x1105 OBEX File Transfer 0x1106 IrMC Sync Command 0x1107 Headset 0x1108 Cordless Telephony 0x1109 Intercom 0x1110 Fax 0x1111 Audio Gateway 0x1112 WAP 0x1113 WAP_CLIENT 0x1114 4.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 8. ATSn=m {Set S Register} As with modems, the Bluetooth module employs a concept of registers which are used to store parameters, such as escape sequence character, inquiry delay time etc, as listed in detail below. The value part ‘m’ can be entered as decimal or hexadecimal. A hexadecimal value is specified via a ‘$’ leading character. For example $1234 is a hexadecimal number.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 Register Default Range Comment S302 0 0..4 Set AVRCP category: 0 is Feature disabled (default) 1 is Player/Recorder 2 is Monitor/Amplifier 3 is Tuner 4 is Menu S303 0 0..0xFFFFFF Set Company ID: IEEE Company ID, 24bit hexadecimal, Required for UNIT INFO Response in AVRCP target mode, default value is 0. S305 1 0..1 Accept UNIT INFO request: 0 – reject 1 – accept S306 1 0..
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 Register Default Range Comment S325 1 0..1 Store link key automatically on dedicated bonding outgoing (DBO), identical with S538 S326 1 0..1 Store link key automatically on general bonding outgoing (GBO) S327 1 0..1 Store link key automatically on dedicated bonding incoming (DBI) S328 1 0..1 Store link key automatically on general bonding incoming (GBI) S329 0 0..
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 Register Default Range Comment S512 1 0..7 Specify power up state. When set to 0, AT+BTO is required to open the device for Bluetooth® activity. When set to 1, it proceeds to a state as if AT+BTO was entered. When set to 2, it will be discoverable only, similar to issuing AT+BTQ. When set to 3, it will be connectable but not discoverable e.g. AT+BTG When set to 4, it will be connectable and discoverable e.g. AT+BTP.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 Register Default Range Comment S531 0 0..5 Specifies the mode on connection establishment. 0 = Normal, that data is exchanged between UART and RF 1 = LOCAL_COMMAND. UART input is parsed by the AT interpreter and RF data is discarded 2 = REMOTE_COMMAND. RF input is parsed by the AT interpreter and UART data is discarded. If S Reg 536 is not 1 then this register cannot be set to 2 and an ERROR will be returned 3 = LOCAL_COMMAND.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 Register Default Range Comment S551 0x3211 0xFFFF This register specifies in each 4 bit nibble, how the outgoing modem status bits to the remote peer gets its value. Bluetooth® allows for RTR, RTC, DV and IC bits to be exchanged over an RFCOMM connection. Nibble 0..3 specifies the source for RTC 4..7 specifies the source for RTR 8..11 specifies the source for DV (i.e. DCD) 12..15 specifies the source for IC (i.e.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 Register Default Range Comment S554 0 0..900 If S Register 512>=2 and <=7 then this register specifies a time in seconds for which the device will stay in the S512 mode after power up or reset. On timeout, it will abort the discoverable and/or connectable and fall back into S512=1 mode, when it is deaf and dumb.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 Register Default Range Comment S592 0 0..1 Set this to 1 to reduce the trusted device database to just 1 record when autosaving of pairing is enabled via S reg 538 S593 0 0..1 Automatically append last 6 digits of local bluetooth address to the friendlyname which was set via AT+BTN or AT+BTF S689 0 -450..+215 Set codec output gain in dBr * 10 S690 0 -450..+215 S730 0 0..1 Enable Auxiliary DAC S731 0 0..
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 13. ATIn {Information} This will return the following information about the Laird Technologies device. I0 The product name/variant. I1 The CSR firmware build number. I2 The Laird Technologies firmware build number. For internal use only. I3 The Laird Technologies firmware revision. I4 A 12 digit hexadecimal number corresponding to the Bluetooth address of the device. I5 The manufacturer of this device.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 14. ATO {Enter Data Mode} (letter ‘o’) Return to data mode. Assume that the module is in data mode after OK is received. Responds with an error if there is no Bluetooth connection. Response: CONNECT 123456789012 Or Response: ERROR nn 15. AT&Fn {Set S Register Defaults} This command will only work when the device is in local command and unconnected mode.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 2. AT+BTC {Set Device Class Code} This command is used to set the device class code which will be sent in subsequent inquiry responses. It can be read back using the AT+BTC? Command, as described below. is a 6 digit hexadecimal number derived as per section “1.2 The Class of Device/Service Field” of the Bluetooth specification “Bluetooth Assigned Numbers”.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 7. AT+BTF {Get Remote Friendly Name} This command gets the remote friendly name of the peer specified. Response: ,”Friendly Name” OK 8. AT+BTG {Enable Cautious Page Scanning ONLY} Enable page scanning and wait for a connection from device with Bluetooth address .
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 12. AT+BTIN {Inquire} As per AT+BTI but the response includes the device class code and friendly name for all inquiry responses. Please refer to the ‘ERROR RESPONSE’ note in the description for AT+BTI. The friendly name strings are in UTF-8 format as per the Bluetooth specification.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 18 AT+BTP {Enable Cautious Page/Inquiry Scanning} Enable page scanning and wait for a connection from device with Bluetooth address . If the specified address is 000000000000 then incoming connections are accepted from any device, is as per AT+BTP without an address. Inquiry scanning is also enabled. Response: OK 19.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 24. AT+BTT {Add Trusted Device} This command is used to store the cached link key in the non-volatile database. If the database is full it will respond with an ERROR. If the device is already in the database, then the key is replaced. If the link key cache is empty, that is, a pairing has not been performed since the device was powered, then the response will be an ERROR.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 Hardware Unit Control This section covers S-Registers and AT-Commands that are related to hardware units within the module. 1. Audio Loopback Mode For testing purposes, an audio loopback mode will be introduced. The stereo audio input signal is fed through the Kalimba DSP with running SBC codec, and is directed back to the audio stereo output. Audio Loopback Mode is controlled with the new AT Command “AT+BTL”.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 Table 3-3: Gain Table Output Gain Level or Input Gain Level S589 or S590 Overall Gain (dBr) S689 or S690 22 +21.5 21 +18.0 20 +15.5 19 +12.0 18 +9.5 17 +6.0 16 +3.5 15 0 14 -3.0 13 -6.0 12 -9.0 11 -12.0 10 -15.0 9 -18.0 8 -21.0 7 -23.5 6 -27.0 5 -29.5 4 -33.0 3 -35.5 2 -39.0 1 -41.5 0 -45.0 Table 3-4: Gain Settings AT Commands and S-Registers 31 www.lairdtech.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 3. Mic Input Gain A microphone preamplifier which adds extra 20dB to input gain, is controlled by S-Register 415. 4. Mic Bias Mic Bias will be enabled with S-Register 416. Mic Bias Current is controlled by S-Register 417. Mic Bias Voltage is controlled by S-Register 418. 5. Auxiliary DAC The auxiliary DAC is enabled with S-Register 730. The DAC output level is set by S-Register 731. 6.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 Table 3-6: A2DP - S-Registers and AT-Commands Task AT-Command / SRegister Comment Set A2DP role S300 [0..
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 3.1.1 Initiate AVRCP control connection AT+AVD Initiate AVRCP control connection to Bluetooth address . The module must be configured as AVRCP Control by S register 301 = 1. Furthermore, a category be selected in S register 302.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 3.1.5 Send remote control command AT+AVC, Send a remote control command to a connected AVRCP target. Internally, a PASS THROUGH command is created and sent to the PANEL subunit of the AVRCP target. is the value for the actual remote control command. Valid values are specified in Table 3 8.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 3.2.4 PASS THROUGH Indication An incoming PASS THROUGH command will be indicated by an unsolicited message AVPTI For subunit_idhex see Table 3 9. For operation_idhex see Table 3 8. : ‘0’ is Button pushed ‘1’ is Button released 3.2.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 37 www.lairdtech.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 Table 3-9: AV/C Unit/Subunit Types Unit / Subunit Type Value Monitor 0x00 Audio 0x01 Printer 0x02 Disc 0x03 Tape recorder player 0x04 Tuner 0x05 CA 0x06 Camera 0x07 Reserved 0x08 Panel 0x09 Bulletin board 0x0A Camera storage 0x0B Vendor unique 0x1C Reserved for all 0x1D Extended 0x1E Unit 0x1F Table 3-10: AVRC Response Types AVRC Response Type Read-Value (S311, sent in response) Write-Value (S311)
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 Secure Simple Pairing (SSP) Secure Simple Pairing is supported on the BT-MM+ module. A set of S Registers provides configuration capabilities for SPP: • Security Level – S320 • IO-Capability – S321 • Force man-in-the-middle-protection (MITM) – S322 • Disable legacy pairing – S323 For details see Table 3 1. Link Key Management On BT-MM+ link keys are managed by the AT firmware. 1. Dedicated Bonding In BT2.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 Miscellaneous 1. Profile Connection Status The connection status of a profile can be queried by an ATI-Command. This might be helpful in order to decide whether to disconnect all connected profiles (via ATH*) or a certain one. For details please see Table 3-12.
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 Appendix BT-MM+ Unsolicited Messages Message Comment CONNECT 0123456789012,110D A2DP control connection established ‘0123456789012’ – bd_ addr of peer device ‘110D’ – Profile UUID indicating A2DP NO CARRIER 110D A2DP connection rejected or closed (if S329==0) CONNECT 0123456789012,110E AVRCP control connection established ‘0123456789012’ – bd_ addr of peer device ‘110E’ – Profile UUID indicating AVRCP NO CARRIER 110E AVRCP c
BTM520/521 Bluetooth® Multimedia Plus Module CONFIGURING THE BTM520/521 42 www.lairdtech.com Error Description 18 Not USED 19 Not USED 20 Not safe to write to Non-volatile Store - Ongoing Bluetooth Connection 21 Link Key Cache is Empty 22 Link Key Database is Full 23 Malloc returned NULL - Resource Issue 24 Remote Address same as Local Address 25 Connection Setup Fail, DSR Not asserted 26 Unauthenticated licence 27 Max Responses (See S Register 518) too high.
BTM520/521 Bluetooth® Multimedia Plus Module Mechanical Details RF OUT MECHANICAL DRAWINGS H 28 39 34 RF Shield b 27 40 TOP VIEW (COMPONENT SIDE) E SIDE VIEW U1 13 12 1 D Pin Outs Description Size Pitch Dimension A A1 A2 b D E e D1 E1 F G H Units H U3 54 Orientation mark on PCB and RF Shield denotes pin 1 54 pin BT Voice Module (8X6 Flash) 20.0 x 14.0 x 2.4mm 1.0mm Minimum Typical Maximum 2.3 2.4 2.7 0.8 0.9 1.0 1.5 1.7 1.3 0.60 0.55 0.65 13.87 14.0 14.13 19.87 20.0 20.13 1.0 11.
B C D Laird Technologies A PIO_6/WLAN_ACT PIO_7/RF_ACTIVE PIO_0/BT_ACTIVE 1 VCC_IO VCC_IO VCC_IO 5 MIC_A_N MIC_B_N MIC_A_P MIC_B_P R13 10K R8 10K R18 10K 2 1 2 1 2 1 2 1 2 R30 2K2 NF SW4 1 2 1 2 NF SW3 NF SW2 NF 3 4 R36 2K2 15pF C11 15pF C14 15pF C13 15pF C12 3 4 3 4 3 4 AGND L2 15n AGND AGND MIC_A_N_DIFF 15n L4 15n L3 15n AGND L1 NF 0R R31 NF 0R R28 NF 0R NF 0R R34 1 1 AGND R38 R32 0R R29 0R NF 15pF C7 R19 NF 0R SPKR_B_N SPKR_A
B C Laird Technologies A PIO_3/RI Module_TX PIO_1/DCD 100n C18 2 1 VCC_3V3 R64 10K 5 AGND AGND SPKR_B_P SPKR_A_P MIC_B_N MIC_A_N R62 10K 1 2 VCC_3V3 10K R56 R52 10K 10K VCC_3V3 PIO_1/DCD PIO_5/DTR Module_RTS RESET_ Module_TX VCC_IO SPI_CS_PC SPI_CLK_PC PIO_5/DTR Module_RTS 2 1 D 1 2 1 2 VCC_IO 10K R44 1 2 1 R65 10K 1 3 5 7 9 11 VCC_IO 1 3 5 7 9 NF 1 3 5 0R 2 NF JP4 R68 JP2 NF Header 6X2 JP1 1 2 4 6 8 10 12 2 4 6 8 10 1 0R 2 R67 2 4 6 R49 1 R66
B C Laird Technologies A JP5 BLM18PG221SN1D USB B Vcc DD+ GND 12 3 4 RESET_FTDI L5 5 D- 10K R84 NF C28 USB_DCD USB_DTR USB_PIO_3/RI USB_DSR 2 2 R85 1 2 N/F 2 Q1 1 USB_MOD_D- 1K R77 2 3 5 USB_MOD_D+ USB+ USB- USB_CTS USB_RTS USB_TX USB_RX NF 0R VDD_CONN NF 0R 2 0R R82 1 R94 1 2 R93 1 10K R78 0R 1 R81 1 CN1 DC Power jack_2.1mm 1 D+ VDD_USB 2 4K7 R88 Diode_S1A 1n C30 IRF5810 4 6 VCC_3V3 10K R87 4.
BTM520/521 Bluetooth® Multimedia Plus Module ORDERING INFORMATION ORDERING INFORMATION BTM520 BTM521 DVK-BTM520 DVK-BTM521 Bluetooth® Multimedia Plus Module (external antenna) Bluetooth® Multimedia Plus Module with integrated antenna Development Board with BTM520 soldered in place 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.
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