I am facing, i think, an isolation problem.
I use arduino Uno R3 to control a motor, through an H-bridge of 4 mosfets and 2 transistors, and to analog read the BEMF of the motor every 1/10th of a second during stopping of PWM.
My experiments was with 5 Volt motor and now i must use a specific motor using 18V, powering the H-bridge from external power supply. I need to read the analog values, so i need usb connection.
How can i do this without damaging the usb ? Do i need an isolation ?
( I have read about ADUM3160, is there any other suggestion? )