Heart diseases have caused millions of death worldwide in the past years because of the increase in the population and rising of health care costs. The main causes of heart attacks are a lack of pre-requisite care and also un-availability of medical care in emergency situations. Treatment and prevention of heart attack is very important. Periodic checkup is important in health maintenance. Electrocardiography(ECG), can be monitor anytime, anywhere and send the report of Electrocardiography(ECG), to the medical expert with this portable device and can effectively communicate with them. In case of any abnormality, doctor will effectively communicate with the patient. For regular checkup and home based checkup, there is need of low cost, portable, low power and time-saving ECG monitoring device. The main requirement of any portable device is low power supply and in this project, there is no need of external power supply because power requirement is completed by harvesting power from mobile phone through audio jack. This paper intends towards developing a device which monitors cardiac activity and will be compact, simple to handle, non-invasive, and reliable. Headphone jack interface could be used to develop modular platforms to monitor vital signs such as Pulse rate, SpO2, EKG.