Too sensitive input on Arduino nano

Hello

I have an input attached on interrupt on Arduino nano, that is enabled when I touch it, maybe some sort of static electricity or something....something that I do not need... How do I fix it?

Thank you...

alex5678: Hello

I have an input attached on interrupt on Arduino nano, that is enabled when I touch it, maybe some sort of static electricity or something.... How do I fix it?

Thank you...

You cannot leave such a pin just floating. Must be connected to ground or to 5 volts through a resistor.

Paul

Use pinMode(pin, INPUT_PULLUP); to enable the internal pull-up resistor.

If it's static discharge the only thing you can do is the obvious - Don't touch it (and/or insulate it).

And of course the same thing will work if it's EMI picked-up by your body.

What's connected? ...Lower resistance will help if it's EMI. But, whatever is connected & driving the interrupt has to be able to drive the lower resistance.

How do I identify and remove spikes from an input pin reading?

Hi, If you use a pullup or pulldown resistor, that will minimise the problem. The input is HI IMPEDANCE so is sensitive to charge.

Tom... :)

TomGeorge: Hi, If you use a pullup or pulldown resistor, that will minimise the problem. The input is HI IMPEDANCE so is sensitive to charge.

Tom... :)

When I use pullup, and when pulldown? On the input a read continuously a 5Volt value, and I want to identify the spikes...

Hi, What are you trying to measure/detect? What is the source of the "spikes"? What voltage are the spikes?

What do you want to when you detect the spikes?

Thanks.. Tom... :)

TomGeorge: Hi, What are you trying to measure/detect? What is the source of the "spikes"? What voltage are the spikes?

What do you want to when you detect the spikes?

Thanks.. Tom... :)

A audio input that is translated on pulses... The source of the spikes is my finger... They are of nanosecond period...

I don't want my circuit to be activated by spikes...

The input is bulit to get activated at 0,6 Vpp...

An interesting finger if it can generate audio signals.

Or, if you want to avoid finger-injected spikes, to quote an old Tommy Cooper joke, ‘just don’t do it’

Allan

Hi,
The source impedance of the audio should be low enough to let you put a 10K resistor from the analog input to gnd.

Have you got the gnd of the audio source connected the gnd of the Nano?

I think it is very important that you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Have you made sure the pulses do not go negative?

Thanks… Tom… :slight_smile:

Have you tried the suggestions of reply 1 or 2? Those should be your first steps toward solving the issue.

alex5678: When I use pullup, and when pulldown?

Use a pull up when you want the normal state of the line to be high.

Use a pull down when you want the normal state of the line to be low.

When you do either of those touching the input will not produce a spike.