Connecting a camera to the embedded industrial control panel for video surveillance seems to be easier to implement, but it is often "ideal is full, realistic and very skinny". After a lot of hard work, it is not very ideal. This article introduces you to various solution. This article refers to the address: http:// Here to introduce to everyone is the need to externally set up, but also to connect the camera, such as the need for CAN bus, multi-port serial port, SPI, LVDS, etc., but also have a camera. This kind of demand is more common in the industries of driving monitoring, driving and training systems, medical treatment, and computer room monitoring. If you have no requirements for peripherals, and only pursue high-definition video surveillance, the Hi3518 solution that goes out to Huawei is more suitable for you. Video surveillance generally has two options: the MCU comes with a camera interface and an external camera interface. The external expansion camera is further divided into: USB solution, Ethernet solution, serial port solution, and the like. In the early days, the more common method of video surveillance was to use the core board of the X86 architecture and directly run the Ubuntu system to install the USB camera. The disadvantage of this method is that it is expensive, consumes a lot of power, and can't run low temperature. The advantage is that the development is difficult. figure 1 1, MCU comes with a camera Later, with the introduction of ARM9, ARM7, A8, A9, many MCUs also come with their own cameras. This kind of scheme obviously has a relatively low cost, but the pixels are not high and cannot be transmitted over long distances. If the risk of debugging based on the original factory is too high, you can choose some core board manufacturers to use their debugged drivers. Even if this requires users to have a certain Linux foundation, they will not play. figure 2 2, USB camera solution The USB camera application is also quite extensive, but this solution has a more headache problem (the Great God bypasses), which is how to solve the USB interference problem. Sometimes it is because the peripheral protection is not done well, and sometimes the camera itself is out of the chain. It is often no problem to make two prototype demonstrations after a lot of hard work, but in the end it was defeated by some details. image 3 3, webcam The price of the webcam is also relatively cheap, and the price of the 720p spherical camera is about 100 yuan. The biggest advantage of this solution is that it is simple and convenient. It can connect multiple HD cameras through the switch, and can use wifi for transmission when the site is not convenient for wiring. Figure 4 4, A9 industrial control board The application of A9 industrial control board is more common based on Freescale's MCIMX6U7C design. The biggest feature is that it supports H.264 hardware decoding and can smoothly run 1080P video. Figure 5 Most web cameras on the market support H.264 encoding, and H.264 provides a network abstraction layer that allows H.264 files to be easily transferred over different networks. The camera video can be played as long as the appropriate player is ported. 5, IP Camera player There are many softwares for playing webcam under Linux: gplayer, gstreamer, ffmpeg, web browser, etc. In the 3.14.28 version of the kernel under Linux, the gstreamer player has been integrated. If you are too lazy to consult the engineer of Guangzhou Zhiyuan, you should write an A9 firmware and test it with the following command line; Figure 6 Iget series Hongkong Onice Limited , https://www.osbvapepen.com
