Microchip Technology IS2083 Series Guide

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INTRODUCTION
The BM83 module is a flash-based Bluetooth Stereo
Audio module built using Microchip’s IS2083 SoC. The
turnkey solution as mentioned in Table 1 integrates the
Bluetooth stack, profiles, and audio/voice processing to
enable Bluetooth audio capability and customize DSP
tuning for an end user application.
This application note describes how to implement and
use the following solutions using the BM83 module:
• Multi-Speaker (MSPK):
- Microchip's Wireless Concert Technology
(WCT) is a distributed audio solution that
synchronizes multiple speakers from one
audio source. This is also known as Multi-
speaker (MSPK) solution.
• Audio Transceiver (AT):
- With AT firmware, the BM83 serves as an
audio source that transmits A2DP music to
standard Bluetooth devices.
• Google Fast Pairing (GFP):
- Uses Bluetooth Low Energy to discover
nearby Android devices, thus eliminating
some of the steps in pairing process.
The BM83 supports the following standard features
along with other features listed in the following table.
• HFP, A2DP and AVRCP
• Audio Mixer
• Bluetooth Low Energy Transparent Service
• OTA Tuning and OTA DFU
• UART Command for Host MCU
• Microchip Bluetooth Audio (MBA) App
Compatibility
The Microchip Bluetooth Audio (MBA) mobile app
connects to the BM83 Bluetooth devices to create an
audio network, adjust EQ settings, volume control, and
perform Over-the-Air (OTA) DSP tuning and firmware
upgrade functions.
Table 1 lists the firmware targets created to support
different functionality as memory constraints do not
allow all features to be implemented in one firmware
image. Each target consists of a firmware image and
default configuration settings. The firmware targets are:
• Phone Book Access Profile (PBAP)
• Google Fast Pairing (GFP)
• Serial Port Profile (SPP)
• Audio Transceiver (AT)
The Config GUI Tool is provided along with the BM83
module to optimize the Noise Reduction (NR), Acoustic
Echo Cancellation (AEC), Audio Mixer and Equalizer
(EQ) Filtering. The BM83 module supports the
following modes:
• Host mode (default configuration):
- Uses the host MCU for advanced system
control
- See Figure 53 to enable this mode using the
Config GUI Tool
TABLE 1: FEATURES SUPPORTED BY BM83
Features
Firmware Targets
PBAP GFP SPP AT
Type Code and Binary Image
Standard Features Y Y Y Y (Rx mode)
A2DP Source N N N Y (Tx mode)
PBAB Y N N N
iAP2/SPP N N Y N
MSPK N Y Y N
AVCRPBrowsing YNYN
Google Fast Pair N Y N N
Legend: Y = Supported, N = Not supported
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IS2083/BM83 Bluetooth®Applications Design Guide

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• Embedded mode:
- Obviates the use of host MCU
- See Figure 54 to enable this mode using the
Config GUI Tool
The IS2083 Software Development Kit (SDK) provides
an opportunity to develop custom code to eliminate the
use of an external host (refer to IS2083 SDK User's
Guide (DS50002894)).
The BM83 supports JTAG for debugging. For details,
refer to IS2083 SDK Debugger User's Guide
(DS50002892).
The BM83 firmware consists of:
• 8051 firmware
• DSP firmware
• Config settings
The Config GUI Tool is used to customize parameters.
For more details, refer to Appendix B: “Customizing
UI and DSP Parameters”.
BM83 firmware can be upgraded using one of the
following methods:
1. Regular method - BM83 devices are put in Test
mode through P3_4 GPIO and using isUpdate
Tool, the BM83 image is updated through UART.
2. OTA DFU - BM83 image is updated through
MBA app. For more details, refer to Appendix
L: “DFU- Over-The-Air Upgrade Procedure”.
3. MCU DFU - BM83 image is updated through
MCU using DFU command #0x49. For more
details, refer to Appendix R: “MCU DFU”.
Note: For more information on the SDK, SDK
User’s Guide, and SDK Debugger Guide,
contact a Microchip sales representative.

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1.0 QUICK REFERENCES
1.1 Reference Documentation
For additional information, refer to the following
documents:
•BM83 Bluetooth®Audio Development Board
User's Guide (DS50002902)
•IS2083 Bluetooth®Stereo Audio SoC Data Sheet
(DS70005403)
•BM83 Bluetooth®Stereo Audio Module Data
Sheet (DS70005402)
• IS2083 SDK User’s Guide
• IS2083 SDK Debugger User’s Guide
• IS2083 isUpdate Tool User’s Guide
1.2 Software Prerequisites
• IS2083 firmware
• Host MCU firmware
• isUpdate tool
• Config GUI tool
• Microchip Bluetooth Audio Application for
smartphone
Note: For a complete list of development support tools, documentation, and software tools downloads, visit http:/
/www.microchip.com/BM83 or http://www.microchip.com/IS2083.

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2.0 MULTI-SPEAKER SOLUTION
The Multi-Speaker (MSPK) Bluetooth Audio solution
utilizes Microchip proprietary technology to connect a
central speaker to one or multiple peripheral speakers
through a modified Bluetooth protocol. Multi-Speaker
functionality is implemented using Microchip’s
IS2083BM device. One (central) speaker can be
connected to a Bluetooth-enabled device (such as a
smartphone, tablet or laptop). A central/speaker can be
connected to a device (phone or tablet), over Bluetooth
or AUX-in jack or built-in microphone, and re-transmit
either of the two audio sources to one or more
speakers acting as a peripheral.
Multi-Speaker solutions can be achieved using
IS2083BM devices, which allow for extended range.
This is a widely used technology for applications such
as PA conference systems or wireless audio
throughout indoor or outdoor.
Multi-Speaker can be provisioned to Concert mode
(one central speaker with one or more peripheral
speakers) or in Stereo mode (a left-channel and a right-
channel speaker). For more details, refer to “MSPK
Demo Setup” and “Firmware Capabilities/
Features”.
Figure 1 illustrates a typical Concert mode application
where the central is connected to a Bluetooth-enabled
device.
FIGURE 1: CONCERT MODE: CENTRAL IS CONNECTED TO BLUETOOTH ENABLED DEVICE
OVER BLUETOOTH
Smartphone or Tablet
IS2083BM
Central
Speaker
IS2083BM
Peripheral
Speaker
IS2083BM
Peripheral
Speaker
IS2083BM
Peripheral
Speaker

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Figure 2 illustrates a typical Concert mode application
where the central is connected to a Bluetooth-enabled
device through AUX-In.
FIGURE 2: CONCERT MODE: CENTRAL IS CONNECTED TO BLUETOOTH-ENABLED DEVICE
THROUGH AUX-IN
Figure 3 illustrates a typical Concert mode application
where the central is connected to a Bluetooth-enabled
device through a built-in analog microphone or built-in
digital microphone. Refer to Appendix W: “MIC as
Input in MSPK” for the Config GUI setting.
FIGURE 3: CONCERT MODE: CENTRAL IS CONNECTED TO BLUETOOTH-ENABLED DEVICE
THROUGH BUILT-IN ANALOG MICROPHONE OR BUILT-IN DIGITAL MICROPHONE
Figure 4 illustrates a typical Stereo mode application
where the central is connected to a Bluetooth-enabled
device.
Alternative Audio
Source
(Amplifier, Sound bar,
Stereo etc.)
Smartphone/Tablet
Aux-in
Connection
IS2083BM
Central
Speaker
IS2083BM
Peripheral
Speaker
OR
IS2083BM
Peripheral
Speaker
IS2083BM
Peripheral
Speaker
Alternative Audio
Source
(Amplifier, Sound bar,
Stereo etc.)
IS2083BM
Central
Speaker
IS2083BM
Peripheral
Speaker
IS2083BM
Peripheral
Speaker
IS2083BM
Peripheral
Speaker
Built-in Analog Mic
or Digital Mic

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FIGURE 4: STEREO MODE: CENTRAL IS CONNECTED TO BLUETOOTH-ENABLED DEVICE
Figure 5 illustrates a typical Stereo mode application
where the central is connected to a Bluetooth-enabled
device through AUX-In.
FIGURE 5: STEREO MODE: CENTRAL IS CONNECTED TO BLUETOOTH-ENABLED DEVICE
THROUGH AUX-IN
IS2083BM
Central
Speaker
IS2083BM
Peripheral
Speaker
Smartphone or Tablet
Alternative Audio
Source
(Amplifier, Sound bar,
Stereo etc.)
Smartphone/Tablet
Aux-in
Connection
IS2083BM
Central
Speaker
IS2083BM
Peripheral
Speaker
OR

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2.1 MSPK Demo Requirements
2.1.1 SOFTWARE REQUIREMENTS
• 8051 firmware
• DSP firmware
• Config settings
• Microchip Bluetooth Audio (MBA) mobile
application
2.1.2 HARDWARE REQUIREMENTS
• The BM83 Bluetooth Audio Development Kit
(DM164152):
- BM83 Evaluation Board (BM83 EVB)
- Type-A to Micro-B USB cable
- 15V DC power adapter
• Bluetooth-enabled smartphone:
- Android™ device running Android 6.0 or later
version
- iOS phone
• Speaker, microphone or headset
• MPLAB REAL ICE/MPLAB ICD 3/PICkit™ 3
• Speakers which accept L+/- and R+/- as input
2.1.3 TOOLS
• isUpdate tool
• Config GUI tool
• MPLAB®Integrated Development Environment
(MPLAB X IDE) tool
• Microchip Bluetooth Audio (MBA) mobile applica-
tion

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2.2 MSPK Demo Setup
The BM83 module supports following modes of
operation in Multi-Speaker solution:
• Embedded mode
• Host mode
2.2.1 EMBEDDED MODE DEMO SETUP
1. Slide SW300 to the ON position to put BM83 into
Test mode.
2. Connect the BM83 EVB with a mini USB and
toggle SW200 switch to the 5V_USB position.
3. Program the MSPK firmware, DSP firmware,
and Config settings (Embedded mode) from the
BM83 MSPK2v1.x package
(IS2083 Turnkey v1.x\Software\IS2083
Image\MSPK2v1.y\SPP\Embedded Mode) into
the BM83 using isUpdate tool. Refer to BM83
Bluetooth®Audio Development Board User’s
Guide, chapter 5. Flash Update for details.
4. Once programming is completed, slide SW300
to position 1 to put device into Application mode.
Refer to Table 2 for Embedded mode button
functionality. By default, BM83 EVB is preconfig-
ured with Embedded mode settings.
5. Repeat step 1 to step 4 with all other EVBs.
2.2.2 HOST MODE DEMO SETUP
1. Follow steps 1 to step 2 from Section 2.2.1
“Embedded Mode Demo Setup” and choose
host mode firmware from BM83 MSPK2v2.1
package (IS2083 Turnkey v1.x\Software\IS2083
Image\MSPK2v1.y\SPP\Host Mode) in step 3.
2. Once programming is completed, slide SW300
to position 1 to put the device into Application
mode. Refer BM83 Bluetooth®Audio Develop-
ment Board User’s Guide, Appendix F: Hard-
ware Setup for Application Demo in Host MCU
Mode. Refer to Table 2 for Host mode button
functionality.
3. Program PIC32 with the PIC32 hex file provided
in the package (\IS2083 Turnkey v1.x\Soft-
ware\PIC32 Image\MSPK2v1.y). Refer to BM83
Bluetooth®Audio Development Board User’s
Guide, Appendix E: Updating PIC32 MCU
Parameters.
4. Repeat steps 1 to 3 with all other EVBs.
Note: To program MSPK firmware (image1),
DSP firmware (image2), and Config set-
tings (image3), the image num value must
be selected as 3 in the isUpdate Tool.

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2.2.3 CONNECTION
Connect the speakers to R/L+/- on (CN1 and CN2) the
BM83 EVB as shown in the following figure.
FIGURE 6: SPEAKERS CONNECTED TO THE AUDIO DAUGHTER CARD
2.2.4 POWER-UP
Connect all the BM83 EVBs to a 15V supply and
change the SW200 switch to the 5V_DC position to
turn on the system.
2.2.5 INSTALLATION
Install the Microchip Bluetooth Audio app on an
Android 6.0 or higher device. Refer to the procedure in
Appendix A: “Android App Installation” to install the
Android application.
2.2.6 PROVISIONING
Multi-Speaker can be provisioned to Concert/Stereo
mode either through pressing the button on the BM83
EVB or through the Microchip Bluetooth Audio app
utilizing BLE UART Transparent mode command.
2.2.7 FUNCTIONALITY OF BUTTONS ON
THE BM83 EVB
The BM83 EVB provides various button functionality.
The following table provides different button
functionality mappings between Host mode and
Embedded mode.
The Android version of the Microchip Bluetooth Audio App is available in the Google Play™ Store and the iOS version
of the app is available in the Apple iTunes®store.

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Note 1: To locate these buttons, refer to Figure 7.
The preceding table shows the default button
functionality for Host mode, which is fixed in PIC32
source code. However, the button functionality in the
PIC32 code can be changed by changing the
command associated with the buttons.
Similarly, button functionality can also be changed in
Embedded mode by re-assignment of GPIO in the
Config UI tool. Button functionality can be configured
using the Config UI tool. Refer to Appendix I: “Button
Configuration”.
TABLE 2: BM83 EVB BUTTONS FUNCTIONALITY
Function Host Mode (1) Embedded Mode
Power-on and entering into Pairing
mode
Short press SEL (SW711) Long press for 2.4 seconds MFB
(SW701)
To enter into Central/Peripheral
mode in Concert mode and to start
grouping
Long press for 1 second VOL UP
(SW702)
Long press for 2 seconds VOL UP
(SW702)
To enter into Central/Peripheral
mode in Stereo mode and to start
grouping
Long press for 1 second VOL DN
(SW705)
Long press for 2 seconds VOL DN
(SW705)
To add a new Peripheral to the
Central in Concert mode
Short double press VOL UP (SW702) Long press VOL UP and VOL DN but-
tons at the same time
To power-off Short press SEL (SW711) Long press for 3.2 seconds MFB
(SW701)
To enter Pairing mode Long press SEL (SW711) Long press MFB
Note: The short press is shorter than 1 second.

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Figure 7 illustrates the functionality of all the buttons
available on the BM83 EVB.
FIGURE 7: BM83 EVB
The following demo steps for Concert mode and Stereo
mode are based on Embedded mode. The functionality
is same for the Host mode as well.
2.3 Concert Mode Demo
Long press MFB on all the BM83 EVBs. This will
power-on the EVB and initialization will be done.
Observe that the Green LED (D401) turns ON and Blue
(D300) and green (D402) LEDs blink. Long press VOL
UP (SW702) on all EVBs. The EVB will either have a
solid Red or Blue LED flashing after a short time period.
The EVB with a solid Red LED (D301) is connected as
a peripheral to the EVB with a flashing Blue LED
(D300) as the central.The EVB where VOL UP
(SW702) is pressed first is provisioned as the central
speaker and the others are provisioned as the
peripheral speaker.
To connect the central speaker with a Bluetooth
streaming device, long press the MFB button on the
central (flashing Blue LED) EVB to enter into Pairing
mode. Pair with a Bluetooth-enabled audio streaming
device. The flashing Blue LED will become solid Blue
on the central EVB once pairing is complete and the
connection is established. Now, play music on the
audio streaming device to hear music on the central
and peripheral speakers.
To add a new peripheral speaker, long press the VOL
UP and VOL DN buttons at the same time on the
central, then long press VOL UP (SW702) on the new
speaker. The new speaker will have a solid Red LED
indicating that it is added as a peripheral speaker in the
group. Music will be heard on the newly added
peripheral speakers along with the central and
peripheral speakers.
To play the audio through AUX-In, connect the central
(flashing/solid Blue LED) with the audio streaming
device through the AUX-In cable. Play music on the
audio streaming device and the audio will be heard on
both the central and peripheral speakers. If Bluetooth
audio was playing before inserting the AUX-In, it will
pause the Bluetooth audio and the AUX-In audio will
start playing. When the AUX-In cable is removed, the
Bluetooth audio will resume in its previous state.
A long press MFB on the central EVB will power-off the
central and connected peripheral EVB.

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2.4 Stereo Mode Demo
Long press MFB on all BM83 EVBs. This will power on
the EVB and initialization will be done. Long press VOL
DN (SW705) on all EVBs. Initially, the Red LED will
flash on all EVBs. The EVB will either have solid Red
or flashing Blue LEDs after some time. The EVB with a
solid Red LED is connected as a peripheral to the EVB
with flashing Blue LED as central. The EVB where VOL
DN (SW705) is pressed first is provisioned as the
central and the remaining are provisioned as
secondaries.
To connect the central with the Bluetooth streaming
device, long press MFB on the central (flashing Blue
LED) to enter into pairing mode. Pair with a Bluetooth-
enabled streaming device. A flashing Blue LED will
become solid Blue on the EVB. Now play music on the
audio streaming device. Music will be heard on the
central and peripheral speakers.
To play the audio through the AUX-In, connect the
central (flashing/solid Blue LED) with the audio
streaming device through the AUX-In cable. Play music
on an audio streaming device and the audio will be
heard on both the central and peripheral speakers. If
Bluetooth audio is playing before inserting the AUX-In,
it will pause the Bluetooth audio and the AUX-In audio
will start playing. When the AUX-In cable is removed,
the Bluetooth audio will resume in its previous state.
A long press MFB on the central EVB will power off the
central and connected peripheral device.
2.5 Concert Mode Provisioning Using
Microchip Bluetooth Audio App
1. Long press MFB on all the BM83 EVBs to power
on the EVB and initialize. The Android app can
also be used to power on individual BM83 EVB.
For more details, refer to Appendix D:
“Android App Power Mode”.
2. Open the Microchip Bluetooth Audio Android
app on an Android phone. The following screen
is displayed, see Figure 8.
FIGURE 8: MICROCHIP BLUETOOTH AUDIO ANDROID APP

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3. A list of connectable BLE devices is displayed.
Select any one device MCHP_Multi_x (see
Figure 8) and assign the role of Central/Periph-
eral. In Concert mode, assign one as the central
and the others as peripheral. Select Concert
Slave to assign one of the BM83 EVBs as a
peripheral (see Figure 9).
FIGURE 9: SELECTING OPERATIONAL MODE

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4. When the device is selected as a peripheral/
central, “grouping” is displayed as the Group
Status (see Figure 10). Then, the Red LED will
start flashing on the BM83 EVB. Repeat this
step for the other peripheral.
FIGURE 10: GROUPING PERIPHERAL/CENTRAL
5. Select Concert Master to assign one of the BM83 EVB as a central, see Figure 11.
FIGURE 11: SELECTING CONCERT CENTRAL

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6. The “Concert Master” is assigned to a BM83 EVB, see Figure 12.
FIGURE 12: STATUS CONCERT CENTRAL
7. From the app, click Concert Master device, then Audio. Next, select Pairing Mode Enter to enter Pairing mode
(see Figure 13). Select Speaker Connection Connect and a list of discoverable Bluetooth devices will be dis-
played on the Android phone; select the device with the name MCHP_Multi_x to pair and connect. Now the con-
cert central device audio is connected.
FIGURE 13: AUDIO CONNECTION

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8. Control the music from the app through Music Control (see Figure 13). Click the Play button and music plays
on both the central and peripheral speakers.
9. For AUX-In mode, connect an audio streaming device with the central (solid/flashing Blue LED) through an audio
AUX-In cable and play music. Music plays on both the central and peripheral speakers.
10. To toggle the audio source, click the Toggle button on the app, as illustrated in Figure 14.
FIGURE 14: TOGGLE AUDIO SOURCE

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2.5.1 ADDING A NEW PERIPHERAL
1. From the app, pause the music. Click the Group Setting tab, then select Concert Master. A small window will
pop up. To add a new peripheral, select Add new slave (see Figure 15).
FIGURE 15: ADDING A NEW PERIPHERAL
2. Go to Scan mode, then click Scan. “Waiting for new slave” displays (see Figure 16). Select Concert Slave to
add as a peripheral.
FIGURE 16: SCANNING FOR NEW PERIPHERAL SPEAKERS
3. A new peripheral speaker is added to the central. Click Scan, then select Concert Master. Play music from the
Audio tab (see Figure 13). Music will be heard on the central and peripheral, including the newly added periph-
eral.

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2.6 Stereo Mode Provisioning Using
Microchip Bluetooth Audio
Android App
1. In Stereo mode, two speakers are used: one as
central and another as peripheral. Stereo mode
provisioning through the Microchip Bluetooth
Audio Android app is similar to Concert mode
provisioning. Select Stereo Master and Stereo
Slave from the app (see Figure 17) in place of
Concert mode central and Concert mode
peripheral in steps 1 through 8 (“Concert Mode
Provisioning Using Microchip Bluetooth
Audio App”). The peripheral will have a solid
Red LED and the central will have a flashing/
solid Blue LED.
2. For AUX-In audio, connect the central (solid/
flashing Blue LED) with an audio streaming
device through the AUX-In cable.
3. The AUX-In and the Bluetooth source can be
toggled from the app toggle button, as illustrated
in Figure 13.
FIGURE 17: PROVISIONING STEREO MODE
Note: It is not mandatory that the Bluetooth streaming device and provisioning device be the same. Instead, one
Android/iOS device can be used for provisioning and another Bluetooth audio device for music play. Pro-
visioning is done through BLE.

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2.6.1 QUICK CENTRAL/PERIPHERAL
SPEAKERS SETUP
The Microchip Bluetooth Audio app has added a new
feature to establish quick central and peripheral
speakers.
1. From the Microchip Bluetooth Audio app, click
Settings, as illustrated in Figure 18.
FIGURE 18: QUICK CENTRAL/PERIPHERAL SETUP

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2. Select Create Personal Group, as illustrated in Figure 19.
FIGURE 19: CREATING PERSONAL GROUP
3. Select Stereo/Concert mode from the pop-up window, as illustrated in Figure 20.
FIGURE 20: SELECTING STEREO/CONCERT MODE