Detecting inductive objects using inputs of integrated circuit device

A system for detecting changes in an electromagnetic field environment field (“EMF”) environment, comprising:

• an inductive sensor circuit configured to generate an oscillating analog waveform having an envelope that decays in response to a change in an electromagnetic field environment;
• an integrated circuit device coupled to the inductive sensor circuit through a timer input capture pin of the integrated circuit device, the integrated circuit device including interface circuitry coupled to the timer input capture pin, a timer and a register, the interface circuitry configured to store a current time value generated by the timer each time the waveform crosses a predetermined threshold;
• and
• a processor coupled to the interface circuitry and configured to retrieve a last stored time value after a time period expires, and to determine a change in the EMF environment based on the last stored time value.

A method of detecting changes in an electromagnetic field environment field (“EMF”) environment, comprising:

• generating an oscillating analog waveform having an envelope that decays in response to a change in an electromagnetic field environment;
• coupling the oscillating analog waveform to a digital input pin of an integrated circuit device;
• processing the oscillating analog waveform to generate a digital pulse from the oscillating analog waveform, the processing including using a digital interface circuit included in the integrated circuit device and coupled to the digital input pin to compare the oscillating analog waveform with first and second threshold levels, where the second threshold level is less than the first threshold level;
• and
• determining a change in the EMF environment based on the digital pulse.

A method of detecting changes in an electromagnetic field environment field (“EMF”) environment, comprising:

• generating an oscillating analog waveform having an envelope that decays in response to a change in an electromagnetic field environment;
• coupling the oscillating analog waveform to a timer input capture pin of an integrated circuit device;
• starting a timer, where the timer is to run for a time period;
• storing a current time value of the timer each time the waveform crosses a threshold level;
• determining that the timer has exceeded the time period;
• and
• determining a change in the EMF environment based on a last stored time value.