BTM51x Series

Not Recommended for New Design (NRND)

Overview

The BTM511 is a low-power Bluetooth module from Laird designed for integrating robust audio and voice capabilities to OEM devices. Based on the market-leading Cambridge Silicon Radio BC05 chipset, these modules provide exceptionally low power consumption with outstanding range. Supporting Bluetooth Version 3.0 specification, these modules provide the important advantage of Simple Secure Pairing (SSP) that improves security and enhances easy use. BTM511 modules come standard with SBC, AAC and apt-X audio codec support for high quality stereo audio applications. 

BTM511 modules are provided with CSR’s apt-X codec without additional license fees. CSR’s world renowned apt-X™ audio compression solutions retain the full integrity of original digital audio and are optimized for instant real-time audio streaming.

To speed product development and integration, Laird has developed a comprehensive AT command interface that simplifies application development, including support for audio and headset functionality. Combined with a low-cost development kit, Laird’s Bluetooth modules provide faster time to market.

Note: The BTM510-xx variant has reached end of production and is available on a limited basis only. Only the BTM510 part numbers are affected. Find the End of Life Announcement in the Documentation tab below.

Specifications

Bluetooth Version
3.0
Antenna Options
Integrated or External via Trace Pad
Chipset
CSR BC05 MM
BT Class
2
Certifications
FCC, IC, CE, MIC
Compliance
Lead-free and RoHS compliant
Connector Type
Multilayer ceramic
Data Rate
Over the Air: Up to 3 Mbps
UART: Greater than 300 Kbps
Dimension (Height - mm)
14 mm
Dimension (Length - mm)
25 mm
Dimension (Width - mm)
3.4 mm
Frequency Range (Max)
2.480 GHz
Frequency Range (Min)
2.402 GHz
Interfaces
Audio Codec: Internal 16-bit Stereo Codec, Integrated Amplifiers for driving stereo speaker
I2S / PCM: Master / slave roles
Microphone: Stereo microphone input
Logical Interfaces
UART (DTR, DSR, DCD and RI, multiplexed with other functionality)
Max Transmit Power
4 dBm
Operating Temp - Max (°C)
+85 °C
Operating Temp - Min (°C)
-40 °C
Power Consumption
Operational - Less than 70 mA (including speaker amplifiers)
Idle (sleep) < 1.0 mA
Configurable Sniff mode and Sniff sub rating
Profiles
SPP (Serial Port Profile), HSP, HFP v1.6 (Audio Gateway and Handset), A2DP (Source and Sink), AVRCP v1.5 (Target and Controller)
Programming Options
API: AT Command Set (extended for audio and headset functions)
Receive Sensitivity
> -86 dBm
Stack On Board
Yes
Storage Temp - Max (°C)
+85 °C
Storage Temp - Min (°C)
-40 °C
Voltage
Supply: 3.0 V to +3.6 V DC
I/O: 1.7 V to +3.6 V DC
Wi-Fi Coexistence
2 wire and 3 wire schemes supported
Antenna Options Bluetooth Version Chipset (Wireless) Connector Type Data Rate Frequency Frequency Range (Max) Frequency Range (Min) Logical Interfaces Max Transmit Power Protocols Range Receive Sensitivity Software Weight Wi-Fi Coexistence Wireless Specification
BTM511 Integrated Antenna v3.0 CSR BC05 SMT 3 MBps 2.4 GHz 2.480 GHz 2.402 GHz SMT +4 dBm AT Command Set Multi-Point API Up to 30 meters -86 dBm Terminal Software .105 oz (3 g) 2 wire and 3 wire schemes supported Bluetooth v3.0
Antenna Options Bluetooth Version Chipset (Wireless) Connector Type Data Rate Frequency Frequency Range (Max) Frequency Range (Min) Logical Interfaces Max Transmit Power Protocols Range Receive Sensitivity Software Weight Wi-Fi Coexistence Wireless Specification Development Kit Contents
DVK-BTM511 Integrated Antenna v3.0 CSR BC05 USB Pluggable 3 MBps 2.4 GHz 2.480 GHz 2.402 GHz USB +4 dBm AT Command Set Multi-Point API Up to 30 meters -86 dBm Terminal Software .105 oz (3 g) 2 wire and 3 wire schemes supported Bluetooth v3.0 Development board and software tools

Documentation

Name Part Type Last Updated
Application Note - Bluetooth Latency and Data.pdf All Application Note 01-17-19
FCC 15C (SST) Grant - BTM511.PDF All Certification 01-23-19
MIC - BTM511.pdf All Certification 01-17-19
IC and CE - Declaration of Conformity - BTM51X.pdf All Certification 01-17-19
IC - RSS-210 Grant (BTM510).pdf All Certification 01-17-19
IC - RSS-210 Grant (BTM511).pdf All Certification 01-17-19
BTM511 IC Certificate.pdf All Certification 01-17-19
BTM510 IC certificate.pdf All Certification 01-17-19
FCC Grant - BTM511.pdf All Certification 01-17-19
FCC Report - BTM511.pdf All Certification 01-17-19
EN 62311 and EN 50385 (RF Exposure) - BTM51x.pdf All Certification 01-17-19
EN 301 489-1 v2.2.0 and 301 489-17 v3.2.0 - BTM51x.pdf All Certification 01-17-19
EN 300 328 (BT EDR) v2.1.1 - BTM51x - 2017.pdf All Certification 01-17-19
EN 60950 - BTM51x.pdf All Certification 01-17-19
EU Declaration of Conformity - BTM51x - 2017.pdf All Certification 01-17-19
Radio Equipment Directive (RED) Updates - May 2017 All Certification 03-01-19
RoHSII - EU WEEE Compliance BT RAMP v1 8 All Certification 07-12-19
Quick Start Guide - BTM51x Development Kit-SPP.pdf All Documentation 01-17-19
Board Schematics - BTM510.pdf All Documentation 01-17-19
Quick Start Guide - BTM51x Development Kit-HFP.pdf All Documentation 01-17-19
Quick Start Guide - BTM51x Development Kit-A2DP and AVRCP.pdf All Documentation 01-17-19
Board Schematics - BTM511.pdf All Documentation 01-17-19
Release Notes - BTM51x Firmware v22.2.5.0.pdf All Documentation 01-17-19
User Guide - BTM510-511 v22.2.5.0.pdf All Documentation 01-17-19
Datasheet - BTM510-511 v22.2.5.0.pdf All Datasheet 03-01-19
FEATURES AND BENEFITS - BTM51X.pdf All Documentation 01-17-19
EOL - Bluetooth - Nov-15-2015.pdf All Documentation 01-17-19
Product Brief - BTM510-511 v.22.2.5.0.pdf All Brochure 03-01-19
BTM510 511 v18.1.4.0 Deploy.zip All Software 01-17-19
BTM510 511 v18.1.4.0 Deploy.zip.zip All Software 01-17-19
Release Notes - BTM51x Firmware.pdf All Software 01-17-19
FW ReleaseNote Btm51x v22 2 5 0.pdf All Software 01-17-19
BTM510 511 v22.2.5.0 Deploy.zip All Software 01-17-19
Bluetooth Development Kit Terminal Download.zip All Software 01-17-19
BTM510 511 v18.1.4.0 Deploy.zip All Software 01-17-19
Application Note - Guidelines for Replacing Antennas v1.0 All Application Note 01-17-19

FAQ

Are there any limitations when using I2S on the BTM511?

Yes, the external I2S circuit should be slave and BTM511 should be I2S master. In addition, the external I2S circuit should not require a high frequency synchronization clock (12 MHz or 24 MHz). The BTM511 is not capable of creating this.

BT 2.1 - SSP initiated by a BTM module

This article is designed to illustrate the process of Simple Secure Pairing (SSP) when initiated from a BTM module. Introduced in Bluetooth v2.1, SSP creates a bond in a very different way than the legacy PIN pairing many users are familiar with. This is demonstrated both for security level 2 (default) and security level 3.

Security Level = 2

Assumptions:

peer device is BT2.1 (supporting secure simple pairing)

security level of BTM device is

security level of peer device is

the pairing initiating device is aware of the peer device's Bluetooth Device Address

Note:  Connections in Bluetooth v2.1 are always encrypted.

 

Figure 1:  BTM vs BTM

Figure 2:  BTM vs PC

Security Level = 3

Assumptions:

peer device is BT2.1 (supporting secure simple pairing)

at least one device with security level = 3 (MITM protection / authentication enabled)

the pairing initiating device is aware of the peer device's Bluetooth Device Address

Remarks:

Connections with BT2.1 are always encrypted

"MITM" = Man-In-The-Middle. "MITM protection" means "protection against a MITM attack".

MITM protection is equivalent with authentication

Figure 3:  BTM vs BTM, security level 3

Figure 4: BTM vs PC, security level 3

BTM51x Series: BTM51x Simultaneous Profiles

On the Laird BTM51x, certain profiles can be used simultaneously (with restrictions) for various use cases. For example, A2DP (stereo audio) can be used at the same time as AVRCP (remote control) so that a Bluetooth speaker (audio sink) can control the music player (audio source) while streaming music.

The following are a few examples of simultaneous profile scenarios on the BTM51x.

1. A2DP, AVRCP, and SPP with one device

Note: A2DP is the Advanced Audio Distribution Profile. AVRCP is the Audio / Video Remote Control Profile. SPP is the Serial Port Profile.

2. A2DP, AVRCP, and SPP with two devices (any combination is possible)

3. A2DP, AVRCP, and SPP with three devices

Can I write my own code for the DSP within the BTM511?

No, not generally. The DSP in the BTM511 is used for certain audio processing algorithms supplied by CSR such as Clear Voice Capture (CVC) and Music Manager. If you have a specific DSP requirement please contact support.

Can the BTM511 act as both an A2DP source and A2DP sink?

Yes, the BTM511 can act as either an A2DP source or an A2DP sink but not both at the same time.

For more information, see our list of  Bluetooth Profiles.

Can the BTM51x produce the Master I2S clock required by an external codec?

Unfortunately, BTM51x cannot provide such MCLK signal. Laird recommends you select an external codec IC which has the capability of creating the MCLK internally from the bit clock signal (SCK). Such capability is referred to as “PLL” (phase locked loop) or “FLL” (frequency locked loop) functionality of the codec device.

Does the BTM511 come with an AAC license?

The BTM511 firmware contains AAC technology which incorporates intellectual property owned by numerous third parties. Supply of this product does not convey a license under the relevant intellectual property of those third parties nor imply any right to use this product in any finished end user or ready-to-use final product. An independent license for such use is required.  A license is not required for development purposes. For details, please visit http://www.vialicensing.com.

Does the BTM511 come with aptX license?

The BTM511 comes with a full aptX licence included in the price of the module.

For more information, see the BTM51X page.

How do I decide what class of device to use for the BTM511?

The class of device (COD) format is defined by the Bluetooth SIG on the following webpage:

https://www.bluetooth.org/en-us/specification/assigned-numbers/baseband

The following site can be useful when generating a COD:

http://bluetooth-pentest.narod.ru/software/bluetooth_class_of_device-se…

A good way of understanding COD is to perform an at+btin command and discover the COD of devices around you. For example if you are working on a Bluetooth speaker, use the command at+btin to find out what COD other Bluetooth speakers are using and then refer back to the web pages linked to above.

How do I put the BTM511 in sleep mode?

When the module is held in RESET, it is considered to be in a deep sleep mode.

Is Sniff Mode supported only as a Slave or as a master or Slave in the BTM41x and BTM51x modules?

Based on a scenario between two BTM41x modules (referenced in the BTM41x Low Power Modes Application Note), the role of a device (master/slave) does not have an impact on sniff mode. In the scenario, sniff mode requests were accepted with requested parameters and were applied on the link, regardless of which end they were initiated from. Thus, at least one end must actively request sniff mode at some point after a connection has been created and the other end must at least not reject sniff mode. If the other end requests sniff mode as well, then the parameters of the most recent request will apply to the link.

Again, this has been done between two BTM41x modules. The relevant source code from this scenario was later ported across to the BTM51x. Confirming tests and measurements have not been carried out on the BTM51x. However, there is no obvious reason why it should behave differently on the BTM51x.

Please note that sniff configuration refers to Rfcomm based links :SPP, HSP, HFP. For AVRCP/A2DP there are some a default setting.

It should be possible to evaluate if a remote device requests sniff mode: Disable local sniff mode by setting Sniff parameters to zero (S561- S564, by default these are zero) and while in a connection check ATi13 repeatedly. If the response is ‘1: b,c,d,e’ then sniff mode has been entered, caused by the remote end. The resulting sniff parameters (b,c,d,e) are likely to be the ones requested by the remote end.

What Bluetooth profiles are supported on the BTM511?

Currently the BTM511 supports , A2DP, SPP, HFP, HF and AVRCP 1.0.

What is the throughput of your bluetooth modules with the embedded AT command interface?

Our fully-embedded modules have a throughput of around 300-360 kbps.  They have an on-board Bluetooth stack and do all of the Bluetooth processing themselves. Bluetooth 2.1 + EDR has a practical transfer rate of 2.1 Mbit/s, but this is not possible on a small embedded module that does not have a powerful PC-type processor.