Speech recognition technology is to enable the computer to "understand" the human language, and then execute the corresponding command according to its meaning, so as to realize the service to the human. With the in-depth study of speech recognition, there are two main aspects of its technical application: one direction is a large vocabulary continuous speech recognition system, which is mainly used in computer dictation machines, and voice information query combined with the telephone network or the Internet. Service systems, these systems are all realized on the computer platform; another important development direction is the application of miniaturization, portable voice products, most of these application systems are implemented using specialized hardware systems. With the advent of the post-PC era, the latter development will become a very hot topic in the cross-study of speech recognition technology and embedded systems, and will further promote the development of speech recognition technology in the direction of intelligence.
Audio interface schematic
The audio codec used by the system is UDAl341t33I. UDAl341 is a monolithic analog-to-digital and digital-to-analog converter with signal processing functions. It is fully integrated analog front end, including programmable amplifier and automatic gain control circuit. Because of the digital signal processing function, it is very suitable for the use of digital audio equipment. UDAl341 supports IIS bus data format, the connection with $3C2440 is very simple, and has a playback mode with DSP characteristics, so it is very suitable for the development of embedded speech recognition systems. The IIS bus is used to solve the data interaction between $3C2440 and the digital audio codec UDAl341. IIS (Inter-IC Sound Bus) is a bus standard developed by Philips for audio data transmission between digital audio devices. In the Philips IIS standard, both the hardware interface specification and the format of digital audio data are specified. The IIS bus only processes sound data. Other signals (such as control signals) must be transmitted separately. In order to make the chip lead as few pins as possible, IIS only uses three serial buses. These three lines are: the data line that provides the time division multiplexing function, the field selection line (channel selection), and the clock signal line. At present, most audio codec chips and microprocessors support the IIS bus standard. The built-in IIS interface of Samsung’s $3C2440 microprocessor used in the system can be connected to many voice processing chips in the market, and has good compatibility. At the same time, S3C2440 also provides a DMA data transfer mode, which can be used without the CPU. Data transmission can be carried out directly, and data can be sent and received at the same time. This is very useful when embedded system resources are limited.
Digital display meter is the abbreviation of digital display instrument. LED and LCD are commonly used as display elements.
Digital display meter has the characteristics of visual intuition, convenient setting and high degree of intelligent control. In addition, with the rapid development of current sensing technology, the function of digital display instrument is becoming more and more powerful and the accuracy is constantly improving. Digital display instrument is replacing traditional mechanical instrument in a large number and has been widely used in all walks of life and daily life.
Digital Display Meter,Digital Display Intelligent Meter,Electrical Connection Digital Display Meter,Intelligent Digital Panel Instrument
Taizhou Jiabo Instrument Technology Co., Ltd. , https://www.taizhoujiabo.com