Systems and methods for retrofitting exercise machines with smart functions

A method for retrofitting exercise machines includes removably attaching a sensor module to a moving part of an exercise machine, the sensor module being configured to detect movements of the moving part and transmit the detected data by a first wireless communication connection, placing a control module in a vicinity of yet separated from the exercise machine, the control module being configured to receive the detected data, calculate an angle value and a speed range using the detected data and transmit the angle value and the speed range by a second wireless communication connection, providing a remote cloud-based application server configured to receive the angle value and the speed range via the second wireless communication connection, verify a user, produce data packets based on the angle value, the speed range and the verified user information and transmit the data packets to a display device.