I'm working on a simple guitar amplifier and reader with Arduino. The Arduino will use this input to find the amplitude and frequency of the input signal.
I'm getting confused about how the ADC inputs should be protected from negative voltages. So far, there's I've found two solutions: Use a diode to stop negative voltages OR offset the voltage. Using a diode seems like it would be easier to calculate the frequency since the negative cycle is just 0V, but I'm afraid that the signal will get too distorted or weak. But I'm just not sure which is the correct one for this situation. Which is the better solution? And why?