Key Technology Research And System Design Of Electromagnetic Electronic Whiteboard

The interactive electronic whiteboard is a type of electron device, which is integrated with kinds of high technologies like computer technology、 communication technology and microelectronics technology and so on. It is only20years since the electronic whiteboard’s invention, but with its advanced technology support、good interactive environment and excellent user experience, it has been getting more and more support and promotion in the field of education.This paper is on account of electromagnetic electronic whiteboard, a important member in the family of electronic whiteboards. Here its functional features、hardware circuit and software system are described in detail, The writer has taken full use of the equipments used in the research and production in the company, and has tested data and methods repeatedly, then three key technology is picked up:First, the electronic whiteboard winding technology was improved. In the production of electromagnetic electronic whiteboard core, the winding process has long been in a low efficiency, the production time is too long, which affects a mass production in a short period of time. In order to change this situation, based on the original winding pattern, a series of improvements was conducted. Then a possibility of improving the efficiency of winding came true by increasing the complexity of the positioning principle. Now it was improved from originally a simple single winding to multi-threaded winding, which can not only improve the production efficiency, but also increase the success rate of winding.Second, the electronic whiteboard positioning algorithm was optimized. The positioning algorithm affects the precision of electronic whiteboard writing, In order to avoid the situation that writing is not smooth like offline and skipping, it is needed to find a accurate and efficient positioning algorithm for the embedded software design. According to the principle of the electromagnetic electronic whiteboard positioning, some factors will affect the voltage collected by electronic whiteboard, the original positioning algorithm will no longer adapt to the change, this paper presented a new positioning algorithm drawing on the experience of centroid algorithm for the capacitive touch technology.Finally, the transformation algorithm between the electronic whiteboard and the computer screen was upgraded. Electronic whiteboard and computer screen are in two different coordinate systems, to complete the synchronization display both of the whiteboard and computer operation, we must implement the transformation of the two different coordinate systems. As an important part of PC driver software, the merits of the coordinate transformation algorithm is related to whether the electronic whiteboard operation is accurate or not. This paper analyzed in detail several common coordinate transformation algorithms. Then based on the perspective transformation with four initial points, we upgraded it to a multipoint transformation to improve the precision of the coordinate transformation.