Computer safety and capacitive touch

Hi, I am new to this discussion. I am trying to work on capacitive touch sensing with my Arduino. But my
computer does not have a battery and I want to print in the results, when people do it on the videos they do not say what precautions they take such as not handling the Arduino while the computer is plugged in or grounding the board and how. Could someone please help me? I am mostly concerned about the general handling of the board while it is plugged in to the computer when the computer is plugged in as well. Thank you!

NO worries. If you're plugged into the computer through the USB port, you're protected from the line voltage. All that's on the USB is 5VDC.

As Delta-G says, your computer supplies just 5v via the USB socket to the board when running on battery or mains, so no problem there. As for handling, you should observe sensible anti-static precautions. I usually set things out on a piece of plain plywood and keep the handling to a minimum while it's powered up. Arduino boards are fairly robust so just handle it by the edges if you need to adjust the position.

Grounding is important, there is some info on grounding on the Arduino CapSense - page.

Sensing doesn't require touching bare metal by the way. I'm currently busy with a small capacative midi- drum project. I use 6x6 cm pieces of PCB, covered with a layer of duct-tape and 3.3 megaohm resistors. Touching the tape is enough to trigger 'm.

Simpson_Jr:
Sensing doesn't require touching bare metal by the way. I'm currently busy with a small capacative midi- drum project. I use 6x6 cm pieces of PCB, covered with a layer of duct-tape

Glass works very well.
Then you can use labels behind the glass.
Leo..

Hi,
If you are using a laptop, the power supply should have a symbol that indicates that it is double insulated, so your safety is assured.

Double Insulated Symbol

Tom… :slight_smile:

Thank you all, I appreciate it! So, I have another question... Let's say you spill your morning coffee on the board while it is plugged in. How would the computer keep you from getting zapped?!? (note, I keep liquids away from my board, just wondering about what would happen!)

I would also like to say I read the page about grounding the Arduino, but I have no clue as to which pin actually grounds the Arduino. Also, is it safe to ground it while it is attached to your laptop? Assuming again you are leaving your laptop plugged in?

I think you are confusing a signal ground with a mains ground. A signal ground is just a common point, that is what is no the Arduino. A mains ground is a safety ground and is actually a connection to the ground soil outside.

Let's say you spill your morning coffee on the board while it is plugged in. How would the computer keep you from getting zapped?!?

The only direct connection with the mains is the power supply, this is sealed therefore you can not get zapped.

However morning coffee is one thing, afternoon tea is lethal. :wink: