Usb-a interface should be one of the most common and universal interfaces.
This kind of universal interface was born 20 years ago, which is mainly designed to facilitate the connection between computer and external equipment. After the introduction of the USB interface, it has been rapidly promoted to other devices, providing them with data transmission and power supply functions. At the same time, it has also extended to many devices with their own USB port.
Although, the emergence of usb-a port brings us a lot of convenience. But you also find that most usb-a interfaces are not compatible with both forward and reverse insertion.
If the equipment is placed in some narrow space, it is not convenient for people to judge the forward and reverse direction of the interface, it becomes a very troublesome thing to connect the data line to the interface. Fortunately, the usb-c port and lightning interface, which are compatible with forward and backward plug-in, are also introduced now, which is more convenient to use.
In view of the problem that usb-a interface can not be compatible with both forward and backward plug-ins, the co developer of USB interface, Ajay Bhatt, explained in the interview with NPR. He said that usb-a does not use the forward and backward plug-in compatible design, which is mainly related to the cost.
According to the verge, Bhatt has tried a lot to design this kind of universal interface. He hopes that this interface can be compatible with most devices, but also simple enough. When he was interviewed by PC world, he used a simple example to illustrate his design intention
When we made this interface, we hoped that it could solve the cable connection problem in the 1990s. In the past, there were too many plugs and connectors, which were very complicated. It was not convenient for people to use them. I hope to have an interface that can help ordinary families quickly connect their computers with printers and print what they need. As long as this interface is convenient enough, they can use it. At the same time, they don’t need to call me for help every time. I think this interface is enough.
Indeed, the emergence of usb-a provides convenience for the connection of many devices. It can not only be used for simple data transmission and power supply, but also can be used to connect external storage devices through USB interface and play the contents directly.
For example, many cars now come with a USB interface, so the car owner can play songs directly by just connecting the U disk. This design is really more convenient than before, when we had to transform the broadcasting equipment in the car.
However, Bhatt also mentioned the problems encountered in this USB interface during his visit, that is, the compatibility between the forward and backward plug-in design and the cost of the interface
It’s not easy to make the USB interface compatible. If you want to use this kind of design, you have to embed twice as many wires and circuits into the USB interface, and the cost will be doubled.
Bhatt also mentioned that they have also considered a circular interface to facilitate blind insertion. But also because of the cost problem, the circular interface was not adopted.
After all, the main goal of universal interface is to popularize. If there is not a big gap in function, but it costs more, then manufacturers and users will not accept it. Therefore, Bhatt’s choice here is also correct. He has chosen a solution with lower cost and convenience for usb-a, which also brings the opportunity to popularize this interface.
Of course, manufacturers already want to turn usb-c into the next generation of universal interface.
Compared with usb-a, the volume of usb-c port is smaller, and its function integration and performance are higher than usb-a. the device can complete power supply, data transmission, display transmission and other functions through one usb-c port, and then it is an inevitable trend to replace usb-a port.