Camera Debugging Method

1. Externally set up the circuit to connect the CRT display

Lead out three leads of power, ground and signal from the analog camera to supply power to the camera, and then connect the video signal line to the video input interface of the TV box. The VGA-OUT of the TV box is connected to the CRT display, so that the CRT can visually display the digitized camera. This method is completely hardware-level display, providing the same display effect as the human eye vision, which is of great help for camera installation and its own physical parameter correction.

2. Off-chip extended LCD liquid crystal

HCS12 series MCUs contain serial peripheral interface SPI (Serial Peripheral Interface), which can realize data transmission between MCUs, and its speed is faster than that through serial asynchronous communication (SCI). The SPI module also supports bidirectional, synchronous, serial communication between the MCU and peripheral devices, and realizes the peripheral expansion of the MCU.

(1) Display characters When the system is running, it prompts the relevant operating parameters of the system in the form of characters. Each character occupies 8*6 point columns and requires 6 bytes of data. To complete the character display, you only need to write the corresponding data to the specified bit in programming. Since the liquid crystal module itself does not have a font library, it is necessary to define the liquid crystal display dot matrix data of ASCII table characters at the beginning of the program, that is, a two-dimensional array with a size of N*6 bytes.

(2) After the video signal collected by the analog camera is digitized by the A/D of the MCU, the information is stored in a 40*70 two-dimensional array, and then the array is binarized, and the 48*84 resolution liquid crystal can be displayed. It is displayed in the module, allowing developers to observe the camera's machine vision in real time.

This method is a display method combining hardware and software, which can track and display the relevant information of the camera in real time without interrupting the system running process during display.

3. Self-written serial communication host computer software

Use the SCI module of the MCU to send the picture data to the PC, and the host computer uses the MSCOMM control programming to read the communication data. After reading the data, you can use the powerful data processing ability and picture display ability of the windows program to process the picture data, such as: redraw the picture according to the data, filter and analyze the array and display the filtering effect, and export the received array as a file. Provide data sources for computer simulations.

This method is a complete software display method. As long as the data is received from the MCU, a series of processing can be implemented on the PC. It has incomparable advantages for checking the effect of graphics transformation, filtering analysis and data simulation ideas.