Android Car Development Summary

　Long time not updated, this morning saw last May left Huayang, wrote a summary report, very feeling, share, also hope that the former company you can become more and more good, to be a worldwide company.

May 29, 2014 10:40

Author:forrestjr [email protected]

Thinking about the industry:

Android system free, free application resources, application Ui/lunch, control and other human-machine interaction interactive development easy customization, so Android car in a big play space, not afraid to do, I'm afraid you can't imagine (the Android app industry chain feeds a huge number of mobile internet companies is a testament).

A lot of times there will be a phenomenon: a mention of Android car, it will be said that the car has no network, there is network download to traffic; in fact, car WiFi and mobile phone hotspot use mobile phone traffic is very convenient, followed by SDcard card offline download installation (can be Network Forum propaganda Guide), can also be directly standard 3G with mobile companies, third-party application companies to promote package services (this model in the mobile phone industry is very popular and mature, but also a good means of propaganda); it can be said that the Android car is actually a mobile phone embedded in the car + traditional car, although different, But the marketing method and design scheme of mobile phone are worth thinking and drawing lessons from.

Thoughts on pre-development choices:

A, Hardware:

1) Chip selection (priority descending):

A, the chip specification needs to meet the vehicle regulation or the work regulation;

b, Chip audio and video interface to be rich; The video needs to support at least 5 inputs (2*CVBS+2*YUV/VGA+HDMI) and 4 outputs (1*CVBS+2*LCD+HDMI), and at least 5 inputs are required for audio (2*micin+2*linein+ PCM/I2S) and three outputs (2*LINEOUT+PCM/I2S), where the audio aspect is easier to meet, and the video input and output needs to be carefully analyzed (for example, if several inputs can be present simultaneously instead of multiplexed, can be output several ways simultaneously on the screen, Whether the video output can be divided into the screen and whether the UI can be redrawn, and so on; This part is the biggest demand difference between the Android car chip and the ordinary mobile phone chip, of course, there are USB, SDcard interface is rich, this demand general on-board chip has a rich interface;

C, the operating power of the chip, as well as the standby power consumption, as well as the power management capabilities of the solution (power management stability); When the real meaning of the mirror fast boot is difficult to achieve, sleep wake is a good alternative to fast boot;

D, the program supported Android and kernel version, Android at least 4.2.2 or more, kernel at least 3.0 or more; Of course if you need to consider the foresight then Android can choose Android4.4( Google Website:Android 4.4 optimized memory footprint and touch screen processing, response speed and accuracy beyond all previous versions, system performance peaks again ;

C, the original support and technical capabilities;

E, compared to the mobile phone performance requirements of the car industry should be low performance, dual-core/four-core +1g 32Bit DDR can meet demand, assuming high-end positioning, improve configuration is relatively simple things;

2) circuit design, as far as possible to simplify the circuit, as far as possible to use the core circuit of the Android Chip program (the original shipment is huge, especially the core circuit has been a lot of verification, not necessary here ingenuity); Minimize the complexity of MCU and MPU in software design, This is based on the simpler things that are less prone to error;

B, Software:

1) Android version integrity and compatibility

A, basic peripheral support at the beginning of the selection scheme is the need to consider Wifi, 3G, BT is enough to have built-in or external can be equipped with the sub-function of each function is fully supported (such as WiFi hotspot, WiFi direct connection, etc.), Among them, Bluetooth will be a function module of problem concentration outbreak;

b, on-board Bluetooth module compared to the mobile phone need to increase the HFP, HID, A2DP, PBAP protocol support, if the use of Android comes with the soft stack, in the beginning of the initial selection of the need to do detailed analysis and adequate preparation , if not done well, this part will become a short board, of course, the choice of module with the stack risk will be reduced, but still need to carefully assess the early, otherwise in the development process will find it is still a short board;

C, sdcard, USB compatibility analysis is needed to evaluate the early (if the compatibility of the cross-border may also require electronic intervention);

d, multimedia compatibility, as well as the multimedia display effect is also very important;

E, MPU side mix output and single sound output, combined with the MCU sound channel, whether it can meet the requirements, is also an important part of the early evaluation of the project;

F, the program Android CTS certification can reach how many hundred percent, the relationship of Android system to the three-party software compatibility;

2) Extended function support: Mirrorcast receive side support, dual screen display, dual screen, background video asynchronous output, background UI drawing, etc. can be used in car functions, before the development of the same need to research and evaluation;

Thinking about the development process:

The development process is the process of realizing and refining the module functions which are evaluated and designed before development.

This part relies on each person's serious treatment, effective communication, each implementation of a function needs to be repeated verification and testing (software and hardware), and in the development process to do a good job of development records:

A, code comments, programming specifications;

B, repeated verification of the refinement function, and verification report;

C, SVN code submission record, and project leader's audit;

D, Development records, problem-solving records, communication minutes;

In the development process relies on the developers of serious, careful, communication and patience, coupled with relatively reasonable development time and incentive measures;

This development process is heavily implemented;

Thinking about post-development and testing:

Late in development, individuals think that at least half the time each developer needs to invest in testing and repeatedly validating functional modules related to their own development; we do products, not just functions;

At the same time, testers also need to carry out high-strength machine test and automatic testing at this stage.

This phase of the task is to identify potential problems, improve the stability of the function, optimize performance;

This stage will make people feel very dull, or irritable, but he does the product of the key link;

Personally, there is no shortcut to this stage, only by hard work, sweat and time to ensure the quality of products;

If the development process is well controlled, each function has been repeatedly verified, development has a detailed record, then the development of the later stage and the test phase will be relatively easy;

This development process is heavy on diligence;

Thinking about the development analysis and design:

Development Analysis should include the early development of project selection and evaluation;

Early development of the project selection and evaluation should also belong to the development process, especially in the embedded industry (it is difficult to have a project leader can understand from top to bottom all the technology), should be the full participation of the development of technical personnel;

Development and analysis can not be in the middle of development or later to supplement, not much effect and significance;

Development analysis should include the part of the product, preferably through the product manager to continuously improve and track;

In the case of perfect development and analysis, good design is the competitiveness and added value of a product;

A good design should be on the basis of a stable platform, can be designed with innovative, improve the user needs of the function, design a sophisticated, comfortable human-computer interface;

product stability, fluency, compatibility is the foundation, and the design of novel, appropriate, comfortable is the vitality of the product;

Android Car Development Summary