The technical note presents explanation around time interval, timer, measurement, calibration, frequency, current oscillator frequency, detection, sensor interface, data, and microchip. In this technical note the reader can read explanation like reset, output, technology, reference, oscillator frequency, sensor, oscillator, current frequency, and current.
Many info around reference frequency, metal detection, interface, metal objects, circuit, input, current oscillator, offset, metal, and microcontroller are described in this technical note. Below are some excerpt from the technical note:
PIC12CXXX microcontroller can be used in quite an unexpected area of application – as an intelligent metal detector. Few components are needed to build a hand held (stand alone) or a static, remotely controlled metal sensor connected to a computer or another microcontroller. As known, the metal objects can change the resonant frequency of an LC circuit. If this circuit is connected to oscillator inputs of PIC, then the operating speed of the microcontroller will be influenced by the metal objects located near inductor L1 (figure2). The microcontroller must measure its own frequency at start up, save it as
reference frequency, and compare it with all other currently measured frequencies. To perform such a type of measurement, a RC circuit (R2,R3,C4) is connected to a GP2 pin and determines a constant time interval for calculations. GP2 has two functions: to discharge the capacitor C4 (as output) and to control its voltage (as input).
In addition, this technical note contains discussion around stop, microchip technology, metal detector, loop, calculating current, clock, inductor, pin, and sensor.