IP-Camera design of FIC8120 and PoE

IP-Camera design of FIC8120 and PoE

In today's digital Internet era, any electronic device strives to develop in the direction of digitization and networking. The network is drawing us closer, and the network is changing our lives. The surveillance field is also developing rapidly towards networking without hesitation, and the networked development of cameras is also unstoppable. [6] IP cameras will make remote video surveillance possible. It will change the dilemma of the original distributed analog cameras that cannot achieve low-cost remote transmission!

In order to meet the needs of distributed single camera long-distance transmission, modern IP cameras must have the characteristics of small bandwidth, high image quality, low cost and low power consumption. This system adopts digital CMOS digital image sensor, MPEG-4 high-compression ratio VGA / CIF ARM-SoC and Si3401 Power over Ethernet and Ethernet device controller, etc. All digital real-time network camera solutions are proposed to meet the current and future needs Monitor demand.

Overall hardware architecture

The whole system is composed of CMOS video acquisition, compression coding, video processing, power over Ethernet and Ethernet data communication. From the front end to the back end, it passes through several processing procedures such as "lens OV7660 → FIC8120-SoC → PoE / Network".

According to the different needs of users, we can choose the corresponding lens group, and the analog information obtained from the lens will be digitally collected by OV7660, and then transmitted by this CMOS sensor to the subsequent processing component.

1. FIC8120-SoC related design

FIC8120 is a highly integrated, MPEG4 / JPEG video image acceleration, low cost and low power consumption, ARM922 core SoC designed by the famous UMC FARADAY Zhiyuan Technology. [1]

FIC8120 as the system CPU, captures the VGA format digital image signal of ITU 656 YUV 4: 2: 2 output by OV7660 [5], and DMA to the external SDRAM through the AHB bus. At the same time, it is transmitted to the internal MPEG-4 Codec for encoding. After the encoding is completed, the relevant processing selected by the user is sent to the Ethernet MAC and output from the network port.

This design supports VGA (640 × 480) @ 30fps and CIF (352 × 240) @ 30fps resolutions and frame rates commonly used in the industry for compression encoding, real-time recording, and has efficient motion detection technology. Motion detection technology is used to trigger recording only when motion pictures are captured, thereby greatly reducing unnecessary disk space occupation. The Codec also supports many advanced technologies such as hardware DCT / IDCT, quantization / inverse quantization, variable-length coding, etc., which significantly improves coding efficiency and significantly reduces power consumption. The system also makes full use of FIC8120's built-in 100K gate MPCA (similar to FPGA), and realizes many functions such as practical OSD (character superposition).

In addition, FIC8120 has a wealth of peripherals and IO, which also provides great convenience for future system upgrades. Here mainly reserved audio compression port (I2S / AC'97) and CCIR601 / YCbCr / RGB video input, etc.

2. Si3401 PoE power design

For the consideration of low power consumption and ease of use, and after verification of the power supply voltage and power, this system uses Silicon Labs' Si3401 Ethernet power supply chip. [3] Power over Ethernet (PoE) is the IEEE 802.3af standard for transmitting electrical energy via Ethernet cables. 802.3af supports two power supply modes, which are spare pair power supply and signal pair power supply. In order not to change the existing network equipment and adapt to the future network equipment, this system adopts spare line power supply mode. [4] Ethernet connects the signal line to the physical layer (PHY) to FIC8120 through the network transformer, and the other free line pair is connected to Si3401 for power supply adjustment. Because IP-Camera is an independent power receiving device, this design configures Si3401 as a non-isolated DC-DC adjustment mode and makes it output a 5VDC initial power supply. Due to the voltage requirements of the CMOS image sensor, CPU, and peripherals, this design uses the LM1117 to step down 5V to 3.3V-1A. Considering that the FIC8120 requires a low noise and high precision 1.8V core voltage, I used the TPS71229 ultra-low noise 250mA dual-channel LDO, which can not only provide reliable and stable 1.8V-250mA, but also provide a CMOS image sensor through the configuration of peripheral circuits The required 2.5V voltage.

System software design

In view of FIC8120's ARM922 architecture, the system transplanted FIC8120 on the low-cost Embedded Linux 2.4.19, and carried out certain cutting and optimization according to FIC8120 and IP-Camera. The system uses the standard GNU tool chain.

Based on FIC8120, we first packaged a board support package (BSP), which includes CPU initialization, memory management, various peripheral drivers (Ethernet, etc.), Linux Kernel initialization, interrupt handling, clock management, watchdog, I / O system and file system etc. BSP is also similar to the initialization and hardware abstraction layer. The upper layer application program makes related calls through the API provided by the BSP. The system initialization program also needs to complete the system's network allocation, video-related parameter configuration (including video resolution, code stream, frame rate, fixed code rate / transcoding rate, etc.), and close unused peripherals to reduce power consumption as much as possible. .

In addition to BSP, the software system also includes IP-Camera key TCP / IP, UDP protocol libraries. The network protocol provided by FARADAY is quite complete and has high real-time performance. [2] Application software includes file system management, network services, mail sending, file transfer, detection and alarm. The network service program finishes sending the video to a certain port of the network for other network devices to access (such as a remote client); when the mail sending and file transfer program detects a moving target and needs an alarm, it sends the video The picture is intercepted and transmitted to the mail server or file server; the detection and alarm program determines whether the moving target in the video needs to be alarmed according to the rules set by the remote host.

The application program also includes a Web Server, and with the dedicated Media Player program, the application software can complete the processing of service requests from the outside according to the HTTP protocol, send the MPEG4 stream to Ethernet, process external control instructions, and detect motion alarms. After connecting to the FIC8120 through the IE browser, you can make relevant settings on the FIC8120 on the page, such as network configuration, multi-stream monitoring, SMTP service, FTP server, video quality, motion detection, administrator password management, etc.

This IP-Camera uses the LAN to remotely access the Web Server under the configuration of VGA resolution, maximum bit rate 2Mbps, frame rate 30fps, bit rate change, motion detection, and performs operations such as preview, recording, playback, and setting, with excellent quality The average storage space occupied by video recording is controlled within 500MB / Hour; the overall power consumption of the system is 3-7W, and the power supply efficiency is> 80%. The system is extremely suitable for widely distributed medium and large-scale monitoring sites. It only needs a network cable and a small amount of Switch / Hub to complete the layout; it can also be recommended for applications such as original equipment transformation and expansion. There is no doubt that this IP-Camera system is one of the current and next-generation digital and networked monitoring and optimization solutions.

references

[1] FARADAY. FIC8120 MPEG4 Codec Platform SoC Datasheet. March, 2006

[2] FARADAY. Faraday Linux Software Development Kit for FIC8120. October, 2005

[3] SILICON LABS. Si3400 / Si3401 Datasheet. December, 2006

[4] SILICON LABS. Using the Si3400 and Si3401 PoE PD Controllers in Isolated and Non-Isolated Designs. AN296. December, 2006

[5] OmniVision. OV7660 / OV7661 Datasheet. 2004

[6] Hou Junhua, Hu Jinyan, Su Boshi, Chen Feng. A new embedded MPEG-4 DVR system design. Microcomputer Information. 2006, Vol.22-No.14, P187-189

Innovative views:

This article designs the industry-leading IP-Camera with all-digital video surveillance and Power over Ethernet as the core. The system is a modern digital network camera solution, which is very suitable for the distributed video surveillance field. Its low power consumption, low cost, and easy maintenance also provide a new development direction for the next generation of video surveillance.

Grating Ruler

Displacement sensor, also known as linear sensor, is a linear device belonging to metal induction. The function of the sensor is to convert various measured physical quantities into electricity. In the production process, the measurement of displacement is generally divided into measuring the physical size and mechanical displacement. According to the different forms of the measured variable, the displacement sensor can be divided into two types: analog and digital. The analog type can be divided into two types: physical property type and structural type. Commonly used displacement sensors are mostly analog structures, including potentiometer-type displacement sensors, inductive displacement sensors, self-aligning machines, capacitive displacement sensors, eddy current displacement sensors, Hall-type displacement sensors, etc. An important advantage of the digital displacement sensor is that it is convenient to send the signal directly into the computer system. This kind of sensor is developing rapidly, and its application is increasingly widespread.

Magnetic Scale Sensor,Magnetic Length Scale,Magnetic Scale Device,Magnetic Scale Measurements

Changchun Guangxing Sensing Technology Co.LTD , https://www.gx-encoder.com