“Wireless Made Easy!" - BM64 Getting Started with Stereo (DSPK) and Multi-speaker (MSPK) modes
The BM64 is a fully-certified Bluetooth 5.0 Audio module for designers who want to add Bluetooth wireless audio and voice applications to their products.
This guide demonstrates the Stereo mode (single speaker or dual speaker: Mono Left and Mono Right) and Multi-speaker mode (two or more speakers).
https://www.microchip.com/bm64
The BM64 is certified Bluetooth 5.0 dual-mode module.
- Bluetooth Classic: BDR/EDR low-level transport layer for audio or voice streaming and SPP for data exchange (provisioning).
- BLE transport for proprietary transparent service to provide a BLE substitute for the Serial Port Protocol (SPP) of classic Bluetooth for use with an Apple® iPhone®, which does not support SPP. (audio commands for working with Android and iOS)
About Bluetooth Audio Technology:
- Highly popular technology found everywhere including smartphone, consumer and professional products along IoT
- It refers to 2 technologies
- Bluetooth Classic : focus on continuously streaming data. Typical use case is Audio with a specific Bluetooth Audio profile called A2DP
- Bluetooth Low Energy (BLE) : focus on sending bulks of data while optimizing power consumption. Highly popular in IoT
- Key things to know about Bluetooth Classic (… and Audio)
- It takes more than Bluetooth to support Audio : audio products typically are dual mode bluetooth (Classic + BLE) with embedded MCU and DSP for audio processing. This is what Microchip proposes !
- A2DP profile could support different music codecs to compress the music files into bit-rates that could then be broadcasted thru Bluetooth
- Popular codecs : low-complexity sub-band codec (SBC), Advanced audio coding (AAC), Sony’s proprietary codecs (LDAC)
- Microchip has BM64 solutions supporting SBC, AAC and LDAC.
- Microchip has solutions for Stereo and Multi speakers, True Wireless earbuds, headsets and headphones
Two options are proposed to our customers:
- the BM64 Class 2 module comes with +2 dBm (typical) output power (headset or mono/stereo speaker) (see DSPK firmware)
- the BM64 Class 1 module comes with +15 dBm (typical) output power to fulfill applications requesting higher range, well suited for multi speaker applications (see MSPK firmware).
Two additional options:
The BM64 module can be configured with one of these two firmware versions.
- DSPK Firmware enables A2DP music streaming to one speaker (mono) or two speakers (stereo: mono left and mono right).
- MSPK Firmware enables A2DP music streaming to more than two speakers from one audio source such as a smartphone. MSPK refers also to Microchip Wireless Concert Technology (WCT).
To evaluate our Bluetooth audio solutions, we've compiled a list of possible speakers compatible with BM64 Evaluation Board.
-> Good, compact speaker for High Resolution demo:
-
Bose Companion 20:
-
Eltax MONITOR I:
-
KRK RP6G3:
-> Simple, light and small speakers for our BM64 EVB demo (not High Resolution): Ideal for mobility and demonstration purpose.
-
Small 5W speakers from AliExpress:
Microchip provides a smartphone App called MBA (Microchip Bluetooth Audio) supporting both Android 6.0 (or higher) and iOS 10.0 (and higher device).
Mobile Application discovers BLE devices and filters the Microchip Audio devices (BM6x or BM8x based) and communicates with them over Microchip’s Proprietary BLE Service called Transparent Service.
This Mobile Application can be used for Stereo (DSPK) or Multi-speaker (MSPK) audio applications.
MBA is available as code sources and as an App in the respective stores.
- The source code of the App for Android and iOS are available to download and both come come along with MSPKv1.35 Software Package (located into "Software\Source Code" folder): http://ww1.microchip.com/downloads/en/DeviceDoc/BM64%20Software%20&%20Tools%20(MSPKv1.35).zip
- The Android version of the MBA app is available from the Google Play™ store: https://play.google.com/store/apps/details?id=com.app.microchip.audiowidget&hl=en
- The iOS version is available in the iTunes® store: https://apps.apple.com/us/app/microchip-bluetooth-audio/id1309473719
BM64 Class 1 Evaluation board: BM-64-EVB-C1
BM64 Class 2 Evaluation board: BM-64-EVB-C2
Kit contains:
Application Note AN2614 introduces DSPK Technology, gives you guidelines to setup then operate your development board in Stereo mode using MBA App or the EVB keyboard (using only MFB key).
This demo is based on DSPK 2.1.2 Firmware. First, update the PIC18 MCU Code, BM64 Firmware and EEPROM parameters by following the steps as described in AN2614.
As a general information, it is strongly recommended to update every single items (MCU code, BM64 Firmware, BM64 EEPROM, ..) from the same Software Package and do not mix the software.
Resources:
- AN2614 - Bluetooth Dual Mode Speaker Audio Application
- DSPK 2.1.2 Software package
- BM64 FW and EEPROM update video
- BM64 FW Update via USB HID
Setup of the environment with basic speakers and smartphone:
In below example (video), the BM64-EVB is powered up via a short press on MFB key (blue light) then ready to pair thru long press to the MFB key (blue and red lights toggle).
Application Note AN2645 introduces MSPK Technology, gives you guidelines to setup then operate your development boards in Multi-Speaker mode using MBA App or the EVB keyboard (using only 2 keys, MFB and SW22).
This demo is based on MSPK 1.35 Firmware. First, update the BM64 Firmware and EEPROM parameters by following the steps as described in AN2645.
Resources:
- AN2645 - Bluetooth Multi-Speaker Audio Application
- MSPK 1.35 Software package
- BM64 FW and EEPROM update video
- BM64 MSPK Stereo Mode Grouping
Setup of the environment with basic speakers and smartphone:
In below example (video), a first board is paired to your smart phone (same procedure explained earlier in paragraph 2.4, "Evaluate Stereo Mode (DSPK)"),
then configured as MASTER, thru long press to the SW22 key (blue light).
Other boards are then powered up (pressing MFB key) and then join the network here again after long press to the SW22 key.
Connecting after the MASTER, they join as SLAVE (RED light).
Up to 35 BM64 speakers have been chained together at trade shows such as CES based on our BM64 Speaker Reference Design from one of our partner.
Just select the device you need from the following link: Buy BM64
Every BM64 modules comes with common feature set:
Surface mount module with
Package Size : 32 x 15 x 2.5 mm
Lead Count : 43
Temp Range : -20C to +70C
Op Voltage Min : 3.2V
Op Voltage Max : 4.2V
Here the ordering information:
BM64SPKS1MC1-00M2AA (Recommended)
- With RF shield
- Certification : CE, FCC, IC, MIC, KCC, NCC, SRRC
- Class 1 module with +15 dBm (typical) output power
- Multi-Speaker firmware (MSPK) - Version 1.35 (Latest release) - Microchip’s Wireless Concert Technology (WCT)
BM64SPKS1MC2-0002AA (Recommended)
- With RF shield
- Certification : CE, FCC, IC, MIC, KCC, NCC, SRRC
- Class 2 module with +2 dBm (typical) output power
- Mono/Stereo Speaker firmware (DSPK) - Version 2.1.2 (Latest release)
BM64SPKA1MC2-0001AA (Legacy)
- Without RF shield
- Certification : CE
- Class 2 module with +2 dBm (typical) output power
- Mono/Stereo Speaker firmware (DSPK) - Version 1.1
BM64SPKS1MC2-0001AA (Legacy)
- With RF shield
- Certification : CE, FCC, IC, MIC, KCC, NCC, SRRC, ANATEL
- Class 2 module with +2 dBm (typical) output power
- Mono/Stereo Speaker firmware (DSPK) - Version 1.1
BM64SPKA1MC1-0001AA (Legacy)
- Without RF shield
- Certification : CE
- Class 1 module with +15 dBm (typical) output power
- Mono/Stereo Speaker firmware (DSPK) - Version 1.1
BM64SPKS1MC1-0001AA (Legacy)
- With RF shield
- Certification : CE, FCC, IC, MIC, KCC, NCC, SRRC
- Class 1 module with +15 dBm (typical) output power
- Mono/Stereo Speaker firmware (DSPK) - Version 1.1
This tutorial explain how to enable BLE Transparent UART communication between BM64 BT Audio Device and BM70 BLE Device
BM64 Data transfer over BLE using Transparent UART while playing music(over A2DP). Hardware used is the BM64-EVB.
The BM70-PICTail is used for this demo, acting as the GATT Client.
The BM70 has its own Transparent UART service so it should not be confused with the BM64's.
Since the BM70 and BM71 are virtually similar, this video applies to both devices.
This relation applies to the BM62 and BM64 as well.
Check out the tutorial here
This tutorial explain how to enable BLE Transparent UART communication between BM64 BT Audio Device and RN4870 BLE Device
The BM64 is acting as a Server and RN4870 is the Client.
Since the RN4870 is optimized to be the Transparent UART Server, it has to be operated in Command Mode to perform writes but it can still receive data when Command Mode is exited.
Since the RN4870 and RN4871 are virtually similar, this video applies to both devices.
This relation applies to the BM62 and BM64 as well.
Check out the tutorial here
