01  What is? A2B Audio bus ？

vehicle A2B link

A2B The full name is Automotive Audio Bus, Car audio bus .

Audio is the core function of intelligent cockpit , It covers car audio 、 speech recognition 、e-Call、 Applications such as noise elimination and echo cancellation , With the development of automotive intelligent networking , The requirements for audio development are also getting higher and higher , Need to add more advanced 、 Rich infotainment functions to meet the user experience of consumers . But the traditional analog parallel audio signal transmission , It is difficult to increase functions and lighten the whole vehicle （ The weight and cost of cables are reduced ） To strike a balance between .

It's time to A2B Audio bus .

A2B The audio bus is used to connect audio devices in the vehicle , Like a microphone （MIC）、 Power amplifier （AMP）、 Multimedia host （Head Unit） and T-BOX etc. . Through a low-cost unshielded twisted pair UTP, Transmit audio data across distances （I2S/TDM）、 Control signals （I2C）、 Clock and power . Digital interface can eliminate peripheral DAC/ADC transformation , Provide simpler audio design 、 More convenient solutions .

 A2B Chrysanthemum chain

A2B Audio bus is a high bandwidth vehicle （50 Mbps）、 two-way 、 Digital audio bus , Adopt the structure of daisy chain , It is a single host （Master）、 Multi slave （Slave） System , Most support 11 Nodes （10 Slave nodes ）, The distance between nodes is the longest 15 rice , The whole daisy chain is the longest 40 rice .

A2B Advantages of audio bus

1 ► Reduce weight and cost

A2B The bus improves the audio performance at the same time , Use fewer cables （ Weight Loss 75%）、 Reduce system and cable costs 、 weight 、 complexity 、 And the fuel consumption of the whole vehicle , Provide simpler audio design 、 More convenient solutions .

2 ► High bandwidth and low delay

A2B Theoretical maximum bandwidth of bus 50Mbps,<50uS Link delay , Support the implementation of ANC Active noise reduction , Realization of functions such as multi zone recognition , Support the implementation of HIFI Hi fi .

3 ► Two way multi-channel transmission

Same article A2B The bus can transmit bidirectional 32 Audio data of channels , You can turn the car 、 Power amplifier 、MIC、T-BOX Wait for nodes to string together , a pair UTP Wires can replace multiple complex harnesses , flexible 、 Low risk 、 Easy to configure , And it can realize the basic configuration and diagnosis of remote nodes .

4 ► Pure digital expandable

A2B The bus is pure digital transmission , Digital interface can eliminate DAC/ADC transformation , Strong anti-interference ability , Maximize audio quality , Improve the user's auditory experience .

With A2B The application of audio bus in automobile is more and more popular , Yes A2B The test of will become an indispensable part of cockpit test .

The key is coming.

02 Test plan

in the light of A2B Audio bus , How to test ？

Our Yixing technology applies different test scenarios for this new technology , Developed supporting test solutions .

scene 1：A2B Input test

The sound processing module developed by Yixing is used as the simulation node , Simulate analog audio signal （ Audio of different frequency bands 、 White noise 、 Dynamic audio 、wav Audio files, etc ） Play through the simulation mouth , And then through MIC Collect analog audio signal , Output to convert from node to A2B digital signal , Output to the locomotive , At the same time, the upper computer reads the information fed back by the vehicle , Form a closed-loop test .

programme 1

scene 2：A2B Output test

The test system controls the vehicle A2B Output , Take the locomotive as the main node ,  Car engine A2B The audio digital signal is transmitted to the slave node , The slave node converts digital signals into analog audio signals and plays them out through speakers , Then collect the analog audio signal through the microphone and enter EPT Self developed sound processing module , It can recognize the collected sound 、 matching 、FFT analysis 、 wave filtering 、 Spectrum analysis, etc , Verify the vehicle's A2B Output function .

programme 2

03  Conclusion

A2B As a new audio transmission method, audio bus , It will be the standard configuration of every car in the future , It may completely replace the current analog audio transmission mode , Then came the upgrading of some peripheral devices , For example, the current analog audio signal MIC、 Speakers need to be integrated A2B chip .

Last , welcome A2B Audio bus related testers contact us , Communicate with us ！