Signal Amplitude Reading

Projects Programming
1

I have 2 khz square waves with different amplitudes in an analog input. How to can i read those signal's amplitude?

2

I'd try a digitalRead to find the rising edge, them immediately do an analogRead

3

Do you know the approximate amplitude? The ADC normally reads between 0 and +5V (assuming a "regular" 5V Arduino). It can be damaged by negative voltages or voltages greater than 5V.

You can run the code from the Analog Read Voltage Example to read the changing voltage in a loop. You can take-out the delay.

4

Is the base line voltage zero or is it less than zero, a negative voltage?
Paul

5

could use a rectifier to make it constant positive amplitude

6

Do you need to detect the amplitude of each cycle of a given 2kHz input or is one 2kHz source going to have fixed amplitude which may be different from another 2kHz source?

If it's the latter you might consider a peak detector circuit; allow it to sample 'N' peaks (characterize what number 'N' is to get a representative peak output corresponding to the amplitude of the input) and then take an ADC reading of the PD output. Use a digital output to trigger the MOSFET to reset the peak value.

1 Like
7

Thanks! That sounds good. I will try it.

8

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