AC Signals in Arduino: Is It Possible?

[fog37]

Hello Everyone,

I have a question about the type of signals that are used in projects involving the microcontroller Arduino or similar ones. It seems that the currents and voltages in these microcontroller's projects all unidirectional, i.e. they can vary with time in different fashions but they are not AC, i.e. they do not change in sign. Is that correct?
If there a specific reason why? After all, a fast changing DC signal is simply a AC signal with a DC offset.

Thanks!
fog37

 

[berkeman]

Hello Everyone,

I have a question about the type of signals that are used in projects involving the microcontroller Arduino or similar ones. It seems that the currents and voltages in these microcontroller's projects all unidirectional, i.e. they can vary with time in different fashions but they are not AC, i.e. they do not change in sign. Is that correct?
If there a specific reason why? After all, a fast changing DC signal is simply a AC signal with a DC offset.

Thanks!
fog37

The signals directly interfacing with the Arduino microcontroller (uC) will be between the 0V-3.3V input voltage range of that uC (please double-check the datasheet to make sure I'm correct on that -- Thanks). The currents will be bidirectional to charge and discharge the parasitic capacitances of the signal lines, to support the changing voltages on those lines.

Hope that helps.

 

[rbelli1]

(please double-check the datasheet to make sure I'm correct on that -- Thanks)

A standard Arduino has 5V IO.

Some of the variants are 3.3V especially the non Atmel ones.

Extra circuitry may be added to allow both positive and negative signals to be used. The easiest would be to use a capacitor to DC block the signal then bias the analog input to half VCC.

BoB