Microchip Technology BM20 User manual

Preliminary Edition
2015 Microchip Technology Inc.
page 1
BM20 Bluetooth®
Evaluation Board User’s Guide

BM20 BLUETOOTH
EVALUTATION BOARD USER’S GUIDE
Preliminary Edition
2015 Microchip Technology Inc.
page 2
Index
Preface........................................................................................................................................4
1 OVERVIEW ..............................................................................................................................6
1.1 INTRODUCTION................................................................................................................................................6
1.2 BM20 EVALUATION BOARD FEATURES ........................................................................................................6
1.3 BM20 EVALUATION BOARD CONTENTS........................................................................................................7
2. Getting Started.....................................................................................................................10
2.1 INTRODUCTION..............................................................................................................................................10
2.2 HARDWARE REQUIREMENTS ......................................................................................................................10
2.3 APPLICATION DEMONSTRATION .................................................................................................................10
2.4 SOFTWARE/UTILITY REQUIREMENTS ........................................................................................................13
2.5 MODULE CONFIGURATION...........................................................................................................................25
APPENDIX A. BM20 AUDIO EVALUATION BOARD SCHEMATICS....................................... 26
APPENDIX B. CLASS D AMPLIFIER DAUGHTER BOARD....................................................32

BM20 BLUETOOTH
EVALUTATION BOARD USER’S GUIDE
Preliminary Edition
2015 Microchip Technology Inc.
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TO OUR VALUED CUSTOMERS
It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip
products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and
enhanced as new volumes and updates are introduced.
If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via
E-mail at [e-mail]. We welcome your feedback.
Most Current Data Sheet
To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at:
http://www.microchip.com
You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page.
The last character of the literature number is the version number, (e.g., DS30000000A is version A of document DS30000000).
Errata
An errata sheet, describingminor operational differences from the data sheet and recommended workarounds,may exist for current
devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the revision
of silicon and revision of document to which it applies.
To determine if an errata sheet exists for a particular device, please check with one of the following:
• Microchip’sWorldwideWeb site; http://www.microchip.com
• Your local Microchip sales office (see last page)
When contacting a sales office, please specify which device, revision of silicon and data sheet (include literature number) you are
using.
Customer Notification System
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Abbreviations List:
HFP: Hands-free Profile
AVRCP: Audio Video Remote Control Profile
A2DP: Advanced Audio Distribution Profile
HSP: Headset Profile
NFC: Near Field Communication

BM20 BLUETOOTH
EVALUTATION BOARD USER’S GUIDE
Preliminary Edition
2015 Microchip Technology Inc.
page 4
Preface
NOTICE TO CUSTOMERS
All documentation becomes dated, and this manual is no exception. Microchip tools
and documentation are constantly evolving to meet customer needs, so some actual
dialogs and/or tool descriptions may differ from those in this document. Please refer to
our web site
(www.microchip.com) to obtain the latest documentation available.
INTRODUCTION
This chapter contains general information that will be useful to know before using the
Product Name. Items discussed in this chapter include:
Document Layout
Recommended Reading
The Microchip Web Site
Customer Support
Document Revision History
DOCUMENT LAYOUT
This user’s guide describes how to use the BM20 Bluetooth Evaluation Board. The document is organized as
follows:
Chapter 1. “Overview” –This chapter introduces the BM20 Bluetooth Evaluation Board and provides an
overview of various features.
Chapter 2. “Getting Started” –This chapter describes
The hardware components and setup of the BM20 Bluetooth Evaluation Board.
The application demonstrations of the BM20 Bluetooth Evaluation Board.
Software/Utility Requirements of the BM20 Bluetooth Evaluation Board.
Appendix A. “BM20 Audio Evaluation Board Schematics” –This appendix includes a schematic of the
BM20 Bluetooth Evaluation Board.
RECOMMENDED READING
This user’s guide describes how to use the BM20 Bluetooth Evaluation Board. Other useful documents are
listed below. The following Microchip documents are available and recommended as supplemental reference
resources:
STEREO Module Data Sheet (DSxxxxxxxx)
THE MICROCHIP WEB SITE
Microchip provides online support via our web site at http://www.microchip.com. This
web site is used as a means to make files and information easily available to
customers. Accessible by using your favorite Internet browser, the web site contains

BM20 BLUETOOTH
EVALUTATION BOARD USER’S GUIDE
Preliminary Edition
2015 Microchip Technology Inc.
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the following information:
Product Support –Data sheets and errata, application notes and sample programs, design resources,
user’s guides and hardware support documents, latest software releases and archived software
General Technical Support –Frequently Asked Questions (FAQs), technical support requests, online
discussion groups, Microchip consultant programmember listing
Business of Microchip –Product selector and ordering guides, latest Microchip press releases, listing of
seminars and events, listings of Microchip sales offices, distributors and factory representatives
CUSTOMER SUPPORT
Users of Microchip products can receive assistance through several channels:
Distributor or Representative
Local Sales Office
Field Application Engineer (FAE)
Technical Support
Customers should contact their distributor, representative or Field Application Engineer
(FAE) for support. Local sales offices are also available to help customers. A listing of
sales offices and locations is included in the back of this document.
Technical support is available through the web site at: http://support.microchip.com
DOCUMENT REVISION HISTORY
Revision A (Aug 2015)
This is the initial released version of this document.

BM20 BLUETOOTH
EVALUTATION BOARD USER’S GUIDE
Preliminary Edition
2015 Microchip Technology Inc.
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1 OVERVIEW
1.1 INTRODUCTION
This user’s guide describes the hardware and software setup for the BM20 Bluetooth®Evaluation Board.
This board contains the hardware needed to evaluate the BM20 Bluetooth module. The BM20 module is
mounted to an evaluation board that demonstrates the module’s key features. The evaluation board contains:
Stereo audio output
Easy access to IO pins
6 push buttons to control audio playback
Status LEDs
The BM20 supports the following Bluetooth profiles: A2DP, AVRCP, and HFP/HSP
A2DP stereo audio (Sink mode wi support for Sub-Band Coding (SBC),
AVRCP media player remote control
HFP/HSP for accepting a phone call support.
For data sheet and other details related to BM20 module, refer to the Microchip web
site at http://www.microchip.com.
This chapter discusses the following topics:
BM20 Evaluation Board Features
BM20 Evaluation Board Contents and Part Details
1.2 BM20 EVALUATION BOARD FEATURES
The BM20 Evaluation Board has the following features:
Fully qualified Bluetooth version 4.1 module, fully compatible with Bluetooth version 3.0, 2.0, 1.2
system.
Embedded BM20 module with postage-stamp size form factor of 15 x 29 x 2.5 mm (include shielding
case)
Embedded Bluetooth stack profiles: A2DP, AVRCP, and HFP/HSP
Stereo audio output for highest quality audio
Castellated SMT pads for easy and reliable PCB mounting
Environmentally friendly, RoHS compliant
Bluetooth SIG certified
On board external CDA for speaker demonstration.

BM20 BLUETOOTH
EVALUTATION BOARD USER’S GUIDE
Preliminary Edition
2015 Microchip Technology Inc.
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1.3 BM20 EVALUATION BOARD CONTENTS
BM20 Evaluation Board contains the following components as shown in Figure 1-1 which describes the
evaluation board’s interfaces and connectors. Table 1-1 describes the various components of the evaluation
board.
FIGURE 1-1: BM20 EVALUATION BOARD
Audio Output (JP23) MIC (JP22) NFC tag connector (JP3)
Pin
Description
Pin
Description
Pin
Description
1
AOHPL
1
MIC_P1
1
NFC_P
2
AOHPM
2
AGND
2
NFC_N
3
AOHPR
3
MIC_N1
1 2 3
1 2 3
1 2

BM20 BLUETOOTH
EVALUTATION BOARD USER’S GUIDE
Preliminary Edition
2015 Microchip Technology Inc.
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IO Connector (J1) On Board External CDA Interface (J2)
Pin
Description
Pin
Description
Pin
Description
1
P0_0
7
P2_4
1
External AMP enable
control(P1_5)
2
P3_0
8
P0_2
2
3
P2_0
9
P0_3
3
R channel signal to external
AMP.
4
P1_5
10
P0_5
4
5
P0_4
11
P2_7
5
L channel signal to external
AMP.
6
P0_1
12
P2_4
6
7
5V power for external AMP
from USB.
8
External AMP Connector (JP26) Battery connector (JP20) and Jack (JP19)
(Alternative for BAT_IN)
Pin
Description
Pin
Description
1
EXT_AMP_EN
1
BAT_IN
2
SPKR
2
GND
3
AGND
4
SPKL
5
AMP_POWER
1 2 3 4 5
2 1
+
1
3
5
7
9
11
2
4
6
8
10
12

BM20 BLUETOOTH
EVALUTATION BOARD USER’S GUIDE
Preliminary Edition
2015 Microchip Technology Inc.
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TABLE 1-1:BM20 EVALUATION BOARD HARDWARE
Hardware Component
Description
BM20
Bluetooth®4.1 Module
USB Connector
DC 5V input, USB to UART for EEPROM R/W
BAT connector & Jack
JP20 and JP19 , alternative for BAT_IN
Audio Out
Audio 3.5 mm jack for audio playback(P6).
External AMP daughter board connector (JP26).
On Board external CDA output connector (J3/4).
Audio In
Audio 3.5 mm jack for Mono microphone input(P5) and AUX input(P7)
Status LEDs
Red and Blue LEDs show the pairing/connection status
MFB Button
Switch to turn on/off BM20 module (SW7; Button 0 in UI)
Play/Pause Button
Button to play or pause the audio playback (SW8; Button1 in UI)
Previous Track Button
Button to skip track backwards (SW4; Button 5 in UI)
Next Track Button
Button to skip track forwards(SW5; Button 4 in UI)
Volume Up Button
Button to increase volume (SW9; Button 2 in UI)
Volume Down Button
Button to decrease volume (SW10; Button 3 in UI)
Reset Button
Reset system (SW11)
NFC Tag Connector
NFC Tag connector.(For NFC tag without Rectifier Circuit)(JP3)
MP Tool Interface
Interfaces connect to VICTORIA board when use MP Tool

BM20 BLUETOOTH
EVALUTATION BOARD USER’S GUIDE
Preliminary Edition
2015 Microchip Technology Inc.
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2. Getting Started
2.1 INTRODUCTION
This chapter describes how the BM20 Evaluation Board works. Certain hardware and utilities are essential to
support the evaluation/development of demo applications. This chapter discusses the following topics:
Hardware Requirements
Software/Utility Requirements
Module Configuration
2.2 HARDWARE REQUIREMENTS
2.2.1 HARDWARE SETUP
To setup the evaluation hardware, perform the following steps:
1. Make sure pin 1 / 2 / 3 of “SW12”in “Off / Off / On”state make .system in application mode.
2. Connect the portable mini-speaker 3.5 mm to the stereo audio out connector (P6).
2.2.2 USING THE EVALUATION BOARD
1. Connect Li-Ion batteries to JP20 or JP19.
2. Click MFB button to turn-on and enter pairing mode. The status LEDs will blink. Now the BM20 Evaluation
board should be discoverable.
3. Turn on Bluetooth device manager on a host device (PC or smartphone), the host device will display a list
of discoverable Bluetooth devices. The board display as “EDDY SHS”.
4. If the pairing with the device is successful, BM20 evaluation board can connect to the host device. Once
connected, BM20 evaluation board enables Advanced Audio Distribution Profile (A2DP) for audio
playback and Audio Video Remote Control Profile (AVRCP) for player control.
2.3 APPLICATION DEMONSTRATION
2.3.1 AUDIO DEMONSTRATION
In this demonstration, user can play an audio stream on both BM20 evaluation boards using a computer or
smartphone. The following are the steps to perform the demonstration.
1. Connect BM20 evaluation board to a host device (PC or smartphone) that has an audio source.
2. Connect headphones (or mini-speakers) to BM20 evaluation board P6.
3. Open the audio source on the host device. Microchip recommends using media player.(e.g. Microsoft
Media Player, iTunes, and Android).
4. Start the audio stream on the media player.
When BM20 evaluation board is connected to an audio source compatible with Bluetooth AVRCP, the audio
control buttons are use to:
Control the volume of audio output.
Go to the previous track.