Design And Realization Of Embedded Controller Based On AT91M55800A

With the development of computer, embedded system has become an important part of computer science and researching focus in recent years. At the same time,with the development of network,it is becoming current to append network function on the controller system.Hereby this paper presents an embedded control system based on AT91M55800A,which has ARM7TDMI core that is a high-performance,small size,low-power consumption core, and is specially suitable for the control filed ritical to the size and the cost.Firstly, the paper set up a hardware system besed on AT91M55800A, which includes MCU,system memery,JTAG debugging interface,TCP/IP network interface,power supply and so on. In order to ensure controller of AT91M55800A running stably, the paper debugging the controller board including AT91M55800A,FLASH memory etc.In order to meet the request of real-time and multi-task control,it anatomize uC/OS-II with fine real-time and open source code,and transplant this operation system to AT91M55800A successfully to realize the function of multi-task. To realize the function of network in uC/OS-II,this paper introduces LwIP(Light Wight IP), especially process of TCP and IP,and then implements driver for LwIP according to RTL8019AS and realizes the communications between the controller and computer based on TCP/IP stack. The test examples of network show that the network interface designed in this paper can communicate with PC susuccessfully based on TCP/IP stack.Finnally,Based on programme of PID and drives of A/D and D/A,the control board is successfully used in controlling the single-tank Liquid Level of the single-tank Liquid Level. Through protocol of MODBUS,the level of the single-tank is monitored by the ForceControl configuration software and the result shows that the controller runs stably.