(Android + Qt minimum system design)
-
The cause of the incident
As more and more market demand for man-machine interface. Embedded customized solutions play an increasingly important role. Modular design, hierarchical become increasingly clear. The control section, a detection section, and so on interactive part. Between the friendly nature of the demand for the product, the interactive part of the general nature of the play "server" products, it plays a schedule of all input "event" initiate and co-ordinate the monitoring of all output "event." So to a sustainable form of embedded development solutions, embedded learning or understanding learning, this understanding is imperative server.
Between this, my team in order to facilitate the follow-up product development and design, we plan to customize a versatile man-machine interface platform. Based on this platform, we are able to expand product solutions feature a variety of needs. The essence of all the design of embedded reference design thinking: modularity. Wanton piece together a product program. Substantially frame model may be as follows:
As shown, based on the root platform HMI programs, various functions derived solutions. In the specific design, effectively cutting ,, put together to form their own products.
That is, design a human-computer platform, "server", the carrier module developed for each follow-up program.
-
Project requirements
A platform designed to support the human-machine interface. Based on this platform, can effectively add its own display (image management), a touch, a subsequent audio program design, with different short-range communication interface, various IO control, storage management, management of high-speed wired communication, wireless communication management scheme distance , the power control scheme (the motor), the power management scheme, the sensor monitoring program, medical equipment industry programs.
This core CPU selection very elegant. Considering that the power consumption, size of the problem, cost, and life cycle issues, high and low compatibility problems, the image processing audio capabilities, high-speed communications, a select RK3288 platform. This platform and the imx6 nxp similar, although the process may be less impressive, but the price special offers. And basically meet the current needs of the mainstream.
Taking into account the design of this program is about to become a universal platform / compatibility and minimum system cutting efforts lowest system, the platform must verify considered the only way to better facilitate the follow-up program put together and not wasteful.
That is part of the general minimum system requirements include the follow-up, as well as to realize the high cost of parts, while this platform with a minimum system itself is the nature of the product, the only way to reflect the independence of embedded modules, do not rely on other modules, can run certain functions. Therefore, power from the CPU, ROM, RAM is necessary. Taking into account the download and debug, so uart USB port and you want to keep.
Since the display does not occupy the interface module, a general interface to be able to meet, such as LVDS interface, the MIPI interface and partly because at the time of high-definition display 4k, for high timing requirements, is placed in the smallest possible system, if this design does not require a subsequent interfaces, welding, or may not be connected.
Standard interfaces similar to the display, substantially touch interface is also standard interfaces, such as I2C, usb. However, it is difficult to compatible usb line sequence, so this part can be considered reserved I2C interface, in use, by the subsequent conversion interface can be designed.
Similar to the display interface, since the external communications for timing the speed of the increasingly high demand. Therefore, a design will be compatible interface board high-speed communication, such as Ethernet 1000M, or support wifi 2.4G / 5G's. Here consider the convenience of a small size, simplicity, Pick 2.4G / 5G disposed on a minimum system, and the current 2.4 / 5g of wifi support Bluetooth, it is good to avoid the back of the Bluetooth designs.
Since the platform design as small as possible, so that resources are not on-chip design, but leads to the pin by pin, pin can plug these ways, can welding.
Which takes into account the current needs of the mainstream and application scenarios, the system must support the minimum system run the mainstream industry or consumer system. Such as android and QT.
The actual requirements are as follows:
| Demand function |
description |
The number of |
| Power Interface / USB Download |
Can be downloaded via the USB interface power supply mode |
1 |
| Power management chip |
The minimum power is supplied to the system, power supply and external expansion port |
1 |
| Power External expansion interface |
3.3v / 5V, one each (recommended) |
2 |
| Serial Debug Interface |
On this USB compatible port download interface, or can be reserved pin pads manner |
1 |
| MIPI display interface |
LCD screen display |
1 |
| I2C expansion port |
An interface pad can be reserved, as a touch reserved |
1 |
| 2.4G / 5Gwifi chip |
External communication, you need a compatible Bluetooth |
1 |
| External expansion interface |
Retention or around the outside row seat pad |
2-4 |
| CPU |
RK3288 |
1 |
| RAM |
1G / 2G / 4G (considering cost pin to pin) |
2/4 |
| ROM |
4G/8G/16G/32G/64G(pin to pin) |
1 |
-
Minimum system solutions
According to the foregoing requirements, the final module design substantially as shown in FIG. Subsequent design may only use this system to achieve a minimum terminal platform, or wifi External Links blue_tooth manner.
Of course, if another special needs, such as the need to expand their sd card, or add an HDMI output display, audio, etc., or add their own modules, their effect can be extended by the above PIN_EX.
The initial plan of the current system to be able to support android system operation, the specific details, see the follow-up of hardware and software design description document.
-
Epilogue
Such a development platform, in particular the use of commuting time savings for us is a challenge, there will certainly be a variety of bumps, updated almost certainly be delayed. But trust me and my team will stick to it.
We will bit by bit throughout the course of our development will be in accordance least once a week a summary way, will share development process documentation and technical development and design for everyone.
However, because of all engineers, and ran a hobby to realize their future flagship platform, so time and money are put into their own, if any friends are interested in this, you can get involved, develop together, grow together. As for the final board, due to the question of money, for personal use only, and those who are interested, we can draw a design, you can contact us, we will provide a version in order to design cost-effective manner, the more people, our own development costs It will lower the (qq group: 744 140 106).
