Hardware Design Of Vehicle Bluetooth Hands-free System With Voice Prompt Function

With a widely applying the modern embedded technology, automobile systems are becoming intelligent, information-based and networked. Bluetooth technology, with its advantage of low-cost, short-distance and wireless, has been widely used in the vehicle system. But a majority of Bluetooth hands-free terminals interact human by on-board display, and their shortcomings are obviously: driver has to make sure the caller's name and phone number on the display, which will certainly lead to his distraction, and even worse like traffic accidents. Voice is one of the most natural intercommunion among human beings. Speech synthesis technology will be obviously helpful in reducing the incidence of traffic accidents.In this paper, based on the background of the subject as well as market demand for automotive electronics, a kind of vehicle bluetooth hands-free system with voice prompt function is designed and developed, and then the details of on-board development work for each unit are described. The necessary circuit descriptions of power unit, Li battery charger unit, vehicle bluetooth hands-free unit, speech synthesis unit, echo cancellation unit and amplifier unit are presented later, as well as the development of driver for echo cancellation chip. And then the design of my PCB files is described, which is according to some basic principles about EMC.The conclusion of test and practice proves that the design is suit to market demand of vehicle Bluetooth hands-free system. Test results show that low power consumption of the system have improved than existing hands-free system in car.