I recently had to make some changes in one of my installation in order to simplify its maintenance.
My installation is basically a 11 meter tall chandelier made of guitars & ukuleles with 2 metallic handles hanging at audience level. When 2 persons, or more, each grab one handle and made skin to skin contact, the arduino measure the resistance in the bodies of these persons and activate one or more dc motors installed close to the strings of the instruments.
It allows the audience to play the guitars and ukuleles by touching each other.
You can have a look on my website : http://romainm.com/monviolond’ingre.html
This installation has been working perfectly for the last 6 months. Unfortunately, for a lot of different reasons, I had to make some change in order to power the all installation with only 1 power box placed under the roof.
I realised that I actually could power my 3V DC Motors with 5V without damaging them (I checked online and made some tests), so I decide to increase my power box at 5V and use it also to power my arduino.
I had to make these changes very quickly so I decide to keep the usb cable that was originally plugged in my arduino, and I connect it to a female usb plug that I took from a charger. I then stripped the cable going out of the female USB plug and connect it directly to the power box.
Unfortunately, now the motors are playing on their own. It looks like the resistance can’t be measured any more. I think it comes from the fact that the changes I made, have kind of connected the digital ground with the analog ground from the arduino.
I made a schema from both the original situation and the one after my changes.
If you have any advice, please let me know.
Thank you for your help.
All the best,