capacitive touch on foil and power bank

Hi all,
my project with a Genuino Micro need to get the capacitive value on a metal foil.
I power up my micro with the microusb on a power generator of 1000mA (the one i use to charge my iphone)
with this kind of power, the circuit works perfectly, also if plugged on the pc.
If i supply the circuit with a portable power bank, i can see change the behavior of my capacitive sensor and it doesn't work perfectly as if plugged on the wall plug or to the pc.
my power bank delivers 1000mA current and i think that it should work in the same way, but this is not.
is like to see the clock of the micro very very slower.
I cannot debug because when connected to the power bank my serial is busy with the power bank itself.

Sorry i'm not a specialist in electronic, i'm trying to do something good to learn and create my project.
Can anyone help me?

Hi Mario,

You should know by now that in order to help, we will need a schematic and your sketch.

is like to see the clock of the micro very very slower.

Can you explain this more. What do you see that makes you think that?

It sounds like you need to see serial monitor while powering the micro through USB from your powerbank. This can be done with some extra components and ingenuity.

A separate USB to serial adaptor like this one is a useful thing to have in your toolkit.
$_1.JPG

The Micro's main serial connections go directly to the USB, but it also has a second serial port. You could connect that to the above adaptor. You can then use Serial1.print() to send debug messages to the PC.

Hi Paul thank you so much for your reply and for your suggestion.
I think that everything works slowly because i can see the behavior of the serial led on the micro that blink very slow compared with the blinking of the other cases mentioned (pc usb or wall mount)
The touch on the foil when powered with the power bank works in a very strange way: sometimes it works good but then immediately the touch doesn't produces actions.
i can't understand, because the code works great with normal power. i was just guessing if the power bank i have is about 1000mAh is too weak to manage that kind of job.
for the sketch and the schematic i need to ask to the company for who i'm working if i can post it.
write u soon
thank you