chris43j
Newbie level 2
This is probably just some very basic concept I am missing but it driving me up the wall. Basically what I want to do is determine the frequency of a signal using an MSP430. I have written the code and it works when I connect my oscilloscope 1kHz output to it. However, what I really want to do is to read the frequency of a sine wave I have generated using an oscillator circuit. I pass it though an opamp which goes rail-to-rail (ie from 0 to 3.5V - same as the micro) and the output to the GPIO. However, the micro doesn't seem to register anything. I thought reading a GPIO input is simply a voltage. If the voltage swing is big enough it is should read it as a 0 or 1 regardless the shape of the waveform no?