Modulation mode and communication circuit based on mobile phone audio interface and communication method of communication circuit based on mobile phone audio interface

The invention discloses a communication circuit based on a mobile phone audio interface. The communication circuit comprises an MCU and a communication processing unit, and can be directly connected with the mobile phone audio interface through a connector, and used devices only include a comparator, an electronic switch, several resistors and several capacitors besides the MCU. Due to the use of the electronic switch, the communication processing unit imitates the mode of a headset for working, and the compatibility between a communication unit and a mobile phone is guaranteed in hardware. In addition, the invention discloses a communication method of the communication circuit. The communication method specifically includes the steps of data frame packing and unpacking, signal coding and decoding and signal inputting and outputting. Particularly, in order to achieve the communication compatibility caused by the difference of hardware circuits inside audio interfaces of different mobile phones, a simple and reliable waveform recovery algorithm is proposed and used, ideal signals are recovered according to signal features, and the communication accuracy and the communication stability are greatly improved.