2.4 ghz bi-directional audio streaming with karaoke for dvds and
TRANSCRIPT
Application ReportSWRA440–November 2013
2.4-GHz Bi-directional Audio Streaming with Karaoke forDVDs and Set Top Boxes (STB) using CC853x
Vikas Thawani and Sanjay Dixit................................................................................ Low-Power Wireless
ABSTRACTThis application note describes the power of the CC853x, which is a 2.4-GHz RF SoC for wireless audiostreaming. A standard CC853x wireless headset development kit is used to make a wireless demo foraudio transmission and reception in a standard IR (infrared) Remote-DVD/STB-TV system. Two audiochannels are transmitted from Remote to DVD, and stereo audio channels are transmitted from DVD toRemote. The built-in Audio protocol of CC853x makes multiple audio channels to co-exist simultaneously.The target applications for the demo are DVD and STBs without doing any software modification to theexisting IR-based system.
Contents1 CC85xx ....................................................................................................................... 12 Existing Remote-STB/DVD-TV system: .................................................................................. 23 Modified System to Establish Bi-Directional Audio Link ............................................................... 24 Conclusion ................................................................................................................... 65 References ................................................................................................................... 66 Schematics ................................................................................................................... 7
List of Figures
1 Typical CC85xx and TLV320AIC3204 Application Schematic ........................................................ 22 Audio Conversion Signal Chain ........................................................................................... 33 CC85xx Headset EVM (Master or Slave)................................................................................ 34 Demo Architecture .......................................................................................................... 45 IR Commands from Remote............................................................................................... 46 Karaoke MIC Audio into Right Channel .................................................................................. 57 Processing of Received RC5 Remote Commands ..................................................................... 58 Add the Received Karaoke Sound to TV Audio Input.................................................................. 69 STB/DVD Stereo Audio Added to MIC Input for Transmission to Remote .......................................... 610 Remote-Side Schematics ................................................................................................. 711 STB-Side Schematics ..................................................................................................... 8
List of Tables
1 CC85xxThe CC85xx are TI’s wireless audio devices that use 2.4-Ghz unlicensed industrial, scientific, and medical(ISM) band. This CC85xx family offers state-of-the-art co-existence and robustness, excellent link budgetand low-power operation while streaming high-quality audio wirelessly. This family has built-in audioprotocol providing excellent robustness and co-existence through multiple techniques such as adaptive-frequency hopping and forward-error correction. CC85xx devices operate autonomously and can be usedwith or without external MCU. The control interface for CC85xx is SPI and the Audio interface is I2S andUSB (CC85x1 only). Different members of the CC85xx family differ in the number of audio channels thatcan be streamed simultaneously and in USB audio support.
1SWRA440–November 2013 2.4 GHz Bi-Directional Audio Streaming with Karaoke for DVDs and Set TopBoxes using CC853xSubmit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Existing Remote-STB/DVD-TV system: www.ti.com
2 Existing Remote-STB/DVD-TV system:The bidirectional wireless Audio demo described in the application note uses the existing IR system. Thesystem consists of IR remote, DVD or STB and an LCD TV. DVD or STB has an IR receiver that decodesIR commands transmitted by remote and controls the DVD operation. This IR system has the followinglimitations:• Range of control• Line of sight is required for control
3 Modified System to Establish Bi-Directional Audio LinkA typical application schematic of the CC85xx Headset reference design kit is shown in Figure 1.
Figure 1. Typical CC85xx and TLV320AIC3204 Application Schematic
The TLV320AIC3204 is a low-power stereo codec that forms the data converter of the system. MIC inputgoes to ADC and is converted to I2S digital audio, whereas the I2S digital audio received is converted toanalog audio by DAC and routed to the headphone output. I2S audio is interfaced with CC8531 that formsthe link between I2S and RF. CC2590 has additional PA and LNA that are used to extend the RF range.Figure 2 illustrates this architecture.
2 2.4 GHz Bi-Directional Audio Streaming with Karaoke for DVDs and Set Top SWRA440–November 2013Boxes using CC853x Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Audio Codec ADC
Audio Codec DAC
CC8531
CC8531 Analog Audio
RFM
RFP
RFM
RFP
Analog IN I2S Audio
I2S Audio
www.ti.com Modified System to Establish Bi-Directional Audio Link
Figure 2. Audio Conversion Signal Chain
The CC85xx headset development kit consists of two similar EVMs, configured as master and slave.Figure 3 illustrates the CC85xx headset EVM (master or slave).
Figure 3. CC85xx Headset EVM (Master or Slave)
The demo architecture is illustrated in Figure 4.
3SWRA440–November 2013 2.4 GHz Bi-Directional Audio Streaming with Karaoke for DVDs and Set TopBoxes using CC853xSubmit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
IR commandsfrom Remote
Pin of Audio codec on CC853x EVM
+
C1
1 µF
1G
ND
2V
S3
OU
T
U2TSOP312XX
R1
10 k
R2
5.6
k
Q1
BC557
R3
1 k
VBAT
VBAT
MICL
Modified System to Establish Bi-Directional Audio Link www.ti.com
Figure 4. Demo Architecture
The default configuration is half duplex and is factory programmed. The following steps were performed toconfigure the demo:1. The EVM was reprogrammed to full duplex mode with both master and slave transmitting and
receiving at the same time.2. IR commands from Remote are captured by IR receiver TSOP312xx (Figure 5), stepped down in
voltage level and fed to the MICL pin of audio codec on Headset EVM located at the remote side.
Figure 5. IR Commands from Remote
3. Karaoke MIC voice data is captured by the Electret Microphone, stepped up in voltage level by 2 stageamplifier, and fed to MICR input of Headset EVM located at the remote side.
4 2.4 GHz Bi-Directional Audio Streaming with Karaoke for DVDs and Set Top SWRA440–November 2013Boxes using CC853x Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
HPL pin
of audio codec on CC853x evm
R1
5
4.7
k
R16
5.6 kC10
10 µF
R21
10 kR22
220 k
R2
3
27
k
R2
4
4.7
k
C11
10 nF
1 2
U1-A74HCT14
3 4
U1-B
74HCT14
5 6
U1-C74HCT14
9 8
U1-D74HCT14
11 10
U1-E74HCT14
13 12
U1-F74HCT14
AK
D1
ML
ED
71
1
J3
R1
5.6 k
C1
560 pF
R2
4.7 k
1 2JMP1
1 2JMP2
D2
BA
T8
5
R3
22
0
R4
22
0
5 IN+
6IN- 7
OUT
U2-BLM393D
5V
HPL
5V
IR_OUT
Electret Mic
Q2
Q3
R5
4.7
k
R6
4.7
k
+C
3
1 µ
F
+C
4
R7
1k
R8
470 k
R9
1 k
R10
220
+C
5C
6
R11
220 k
R12
470 k
R13
1 k
C7
VBATVBAT
VBAT
1 µ
F
1 µ
F
R14
2.2
k
MICBIAS
IN1R of CodecMIC Jack
Karaoke Mic audiointo right channel
CC8531 Headset EVM
+
1 µ
F
10 µ
F
+
www.ti.com Modified System to Establish Bi-Directional Audio Link
Figure 6. Karaoke MIC Audio into Right Channel
4. A wireless audio link is established between the remote-side EVM and the STB/DVD-side EVM. Thisenables the STB/DVD EVM to receive IR commands in RF format, and CC8531 converts the receivedsignal in digital I2S format. Audio codec on the EVM converts the digital audio to analog. This signal isconverted to 5-V logic level RC5 signal. A 36-kHz square wave is used to modulate RC5 and drive anIR LED. This IR LED, when kept in front of STB/DVD, will respond to IR commands without openingthe STB/DVD.
Figure 7. Processing of Received RC5 Remote Commands
5. The right RF channel received on the STB/DVD side is Karaoke voice that is converted back to digitalI2S. The digital I2S audio is converted back to analog output received at right Headphone channel, andis fed into TV audio along with STB/DVD audio. Hence, a karaoke effect is in place.
5SWRA440–November 2013 2.4 GHz Bi-Directional Audio Streaming with Karaoke for DVDs and Set TopBoxes using CC853xSubmit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
Transmitted for remote side.
C5
1µ
F
C6
1µ
F
1
3
2
J4
STB_LOUT
STB_ROUT
MICL
MICR
C9
1 µF
R17
4.7 k
R18
4.7 k
R19
4.7 kR20
4.7 k
1
3
2
J5
HPR
STB_LOUT
STB_ROUT
TV_LIN
TV_RIN
Conclusion www.ti.com
Figure 8. Add the Received Karaoke Sound to TV Audio Input
6. The STB/DVD stereo audio output is also fed to Microphone MICL and MICR inputs of DVD/STB-sideEVM. Remote side EVM receives the audio wirelessly. CC853x converts RF audio to digital I2S audio.Audio codec on board changes digital audio to analog output that is routed to headphones connectedat the Headphone jack of the remote-side EVM. Thus, the person viewing a movie can listen to audioon headphones and mute the TV output, a case helpful for viewing late night television.
Figure 9. STB/DVD Stereo Audio Added to MIC Input for Transmission to Remote
The previous steps help to setup a four channel wireless audio link between Remote and STB. Twochannels, MIC and IR commands, are streamed from remote to STB/DVD, and two stereo audio channelsare streamed from STB/DVD side to Remote headphones. Throughout the demo, no software changeswere made either on the remote side or on the DVD/STB side.
4 ConclusionThe remote EVM can be hooked to any standard IR Remote. The STB EVM can be placed in front of anySTB/DVD and has the capability to communicate with the IR receiver inside. This demo can further beextended if a voice decoding engine is made on the STB side, and STB can be controlled by voicecommands from Remote. CC8531 can support wireless streaming of up to 4 audio channelssimultaneously. There are no audio dropouts, as shown in the above demo, and multiple channels can co-exist. This fact makes CC85xx an excellent choice for applications like wireless headphones, wirelessloudspeakers and wireless 2.1 audio systems.
5 ReferencesUse the following references for additional information:1. CC85xx datasheet (SWRS091)2. CC85xx Headset Quick Start Guide (SWRU282)3. CC85xxDK Headset User's Guide (SWRU281)4. CC85xx Design Documents (SWRR079)
6 2.4 GHz Bi-Directional Audio Streaming with Karaoke for DVDs and Set Top SWRA440–November 2013Boxes using CC853x Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
IR commands
from Remote
Electret Mic
Pin of Audio codec on CC853x EVM
R1 on CC853x EVM popped out
To disable karaoke- Install JMP2
To enable Karaoke, install JMP1
MICR input of CC853x EVM
Notes:
1. Remote can be powered from a Li ion battery.
+
C1
1µF
Q2
Q3
J1
R5
4.7
k
R6
4.7
k
+C
3
1µ
F+
C4
1µ
F
R7
1k
R8
47
0k
R9
1k
R1
0
22
0
+C
5
1µ
F
+C
6
1µ
F
R11
220k
R1
2
47
0k
R1
3
1k
1G
ND
2V
S3
OU
T
U2TSOP312XX
11
22
J3
CONN_1706358
+C
2
1µ
F
1 2
JMP1
12
JM
P2
R1
10k
R2
5.6
k
Q1
BC557
R3
1k
VBATVBAT
VBAT
VBAT
VBAT
MICR
VBAT
MICL
USB is used for testing.
www.ti.com Schematics
6 SchematicsFigure 10 and Figure 11 illustrate the Remote-side and STB-side schematics for audio streaming using CC853x.
Figure 10. Remote-Side Schematics
7SWRA440–November 2013 2.4 GHz Bi-Directional Audio Streaming with Karaoke for DVDs and Set TopBoxes using CC853xSubmit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
CC8531 Headset EVM
Transmitted for remote side
HPL pin
of audio codec on CC853x evm
CC8531 Headset EVM
Notes:1. Whole system can be powered from 5V at STB side. 7805 option is on PCB.
2. J4 is dual RCA connector where STB stereo audio is routed.
3. J5 is dual RCA connector where Karaoke is added and stereo audio is fed to TV.
4. IR LED should be placed close enough so that it is able to communicate with IR Receiver inside STB/DVD.
5. Either of JMP1 or JMP2 is used according to polarity of IR receiver inside STB/DVD.
C9
1µ
F
R15
4.7
k
R16
5.6k
R17
4.7k
R18
4.7k
R19
4.7k
R20
4.7k
C10
10nF
R21
10k R22
220k
R23
27k
R24
4.7
k
C11
10nF
1 2
U1-A
74HCT14
3 4
U1-B
74HCT14
5 6
U1-C
74HCT14
9 8
U1-D
74HCT14
11 10
U1-E
74HCT14
13 12
U1-F
74HCT14
AKD1
MLE
D71
1J3
R1
5.6k
C1
560pF
R2
4.7k
1 2
JMP1
1 2
JMP2
D2
BA
T85
R3
220
R4
220
3 IN+
2 IN-
1
OUT
8
VC
C
4
GN
D
U2-ALM393D
5 IN+
6 IN–7
OUT
U2-B
LM393D
C2
0.1
µF
R5
4.7
k
1IN
2
GND
3OUT
U3
MC7805CT
C3
10µF
C4
10µF
C5
1µ
F
C6
1µ
F
1
3
2
J4
1
3
2
J5
5V
HPL
HPR
5V
STB_LOUT
STB_ROUT
STB_LOUT
STB_ROUT
TV_LIN
TV_RIN
IR_OUT
5V
5V
MICL
MICR
Schematics www.ti.com
Figure 11. STB-Side Schematics
8 2.4 GHz Bi-Directional Audio Streaming with Karaoke for DVDs and Set Top SWRA440–November 2013Boxes using CC853x Submit Documentation Feedback
Copyright © 2013, Texas Instruments Incorporated
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and otherchanges to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latestissue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current andcomplete. All semiconductor products (also referred to herein as “components”) are sold subject to TI’s terms and conditions of salesupplied at the time of order acknowledgment.
TI warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in TI’s termsand conditions of sale of semiconductor products. Testing and other quality control techniques are used to the extent TI deems necessaryto support this warranty. Except where mandated by applicable law, testing of all parameters of each component is not necessarilyperformed.
TI assumes no liability for applications assistance or the design of Buyers’ products. Buyers are responsible for their products andapplications using TI components. To minimize the risks associated with Buyers’ products and applications, Buyers should provideadequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, orother intellectual property right relating to any combination, machine, or process in which TI components or services are used. Informationpublished by TI regarding third-party products or services does not constitute a license to use such products or services or a warranty orendorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of thethird party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of significant portions of TI information in TI data books or data sheets is permissible only if reproduction is without alterationand is accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such altereddocumentation. Information of third parties may be subject to additional restrictions.
Resale of TI components or services with statements different from or beyond the parameters stated by TI for that component or servicevoids all express and any implied warranties for the associated TI component or service and is an unfair and deceptive business practice.TI is not responsible or liable for any such statements.
Buyer acknowledges and agrees that it is solely responsible for compliance with all legal, regulatory and safety-related requirementsconcerning its products, and any use of TI components in its applications, notwithstanding any applications-related information or supportthat may be provided by TI. Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards whichanticipate dangerous consequences of failures, monitor failures and their consequences, lessen the likelihood of failures that might causeharm and take appropriate remedial actions. Buyer will fully indemnify TI and its representatives against any damages arising out of the useof any TI components in safety-critical applications.
In some cases, TI components may be promoted specifically to facilitate safety-related applications. With such components, TI’s goal is tohelp enable customers to design and create their own end-product solutions that meet applicable functional safety standards andrequirements. Nonetheless, such components are subject to these terms.
No TI components are authorized for use in FDA Class III (or similar life-critical medical equipment) unless authorized officers of the partieshave executed a special agreement specifically governing such use.
Only those TI components which TI has specifically designated as military grade or “enhanced plastic” are designed and intended for use inmilitary/aerospace applications or environments. Buyer acknowledges and agrees that any military or aerospace use of TI componentswhich have not been so designated is solely at the Buyer's risk, and that Buyer is solely responsible for compliance with all legal andregulatory requirements in connection with such use.
TI has specifically designated certain components as meeting ISO/TS16949 requirements, mainly for automotive use. In any case of use ofnon-designated products, TI will not be responsible for any failure to meet ISO/TS16949.
Products Applications
Audio www.ti.com/audio Automotive and Transportation www.ti.com/automotive
Amplifiers amplifier.ti.com Communications and Telecom www.ti.com/communications
Data Converters dataconverter.ti.com Computers and Peripherals www.ti.com/computers
DLP® Products www.dlp.com Consumer Electronics www.ti.com/consumer-apps
DSP dsp.ti.com Energy and Lighting www.ti.com/energy
Clocks and Timers www.ti.com/clocks Industrial www.ti.com/industrial
Interface interface.ti.com Medical www.ti.com/medical
Logic logic.ti.com Security www.ti.com/security
Power Mgmt power.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense
Microcontrollers microcontroller.ti.com Video and Imaging www.ti.com/video
RFID www.ti-rfid.com
OMAP Applications Processors www.ti.com/omap TI E2E Community e2e.ti.com
Wireless Connectivity www.ti.com/wirelessconnectivity
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265Copyright © 2013, Texas Instruments Incorporated