Earphone drive-by-wire circuit of mobile phone and drive-by-wire method

The invention discloses an earphone drive-by-wire circuit of a mobile phone and a drive-by-wire method. The method comprises the following steps: providing a working voltage; acquiring a microphone voltage value on an earphone joint; computing a resistance value of the microphone according to the microphone voltage value on the earphone joint; computing a working voltage value of a control key according to the resistance value of the microphone; and judging whether to press down the control key according to the acquired voltage value on the earphone joint. In such a way, the invention can adapt to microphones with different resistances, so that the microphone is available under unknown resistance.