Master Module Design Based On The At91rm9200 Digital Mixer

With the development of micro-electronics, computer and network technology, embedded systems are entering our lives by a striking speed and are affecting to the way that we live and work. The new generation of digital audio mixer is just the embedded product which is made up by the micro-processor and network technology.The process of the hardware system and software system developing is in detail discussed in this paper. Firstly, the definition, character, basis composing of the embedded system and the basic function of the digital audio mixer are introduced in short. Secondly, the composing and characteristics of the mixer to design are put up in this paper. The whole system is divided into three parts according to the mixer's function: the audio processing module, the main controlling module and the channel module. The designing of the main controlling module is mainly discussed in this paper. Thirdly, the designing of the hardware system and the transplant of the embedded Linux OS is introduced too. Fourthly, the basis theory of the driver programming under the Linux OS is introduced. And the design of the peripheral interface and how to program the device driver is also explained. At last, it summarizes the whole design and put forward some deficiency and insufficiency witch need to improve in later.Taken full advantage of the network technology is the main feature of the digital audio mixer which this paper covers. The main controlling module and the audio processing module are all connected to the Ethernet. The main module performs all kinds of controlling operations and obtains status of the processing module. The communication between the main and the processing module is through the Ethernet and by the SNMP (simple net manager protocol). It builds up a principal and subordinate network by CAN bus between the main module and the channel modules. The channel modules get the parameter settings and data of each channel and send them to the main controlling module and the main controlling module sends them to the audio processing module by SNMP if necessary. At the same time, the main controlling module also obtain the status of every channel from the performing module by SNMP and sends them to channel module by CAN bus. It can achieve the distributing design of mixer when the main controlling module and the processing module are connected to the Ethernet and at the same time it can update the program and maintenance the device at long-distance. The principal and subordinate network by CAN bus between the main controlling module and the channel modules is convenience to the expanding of the sub channel modules, thus it is easy to change the number of the sub channel module according the actual need.