good day .
I'm new and I'm trouble arduino to control 4 servos.
it happens that when handling them by bluetooth or serial monitor, the servos start to shiver - vibrate and / or make involuntary movements. If I send a command to a servo move , another makes any uncontrolled movement. It's crazy.
The servo are connected to an external source of 5V and 650 mA .
Programming is correct.
Please help
P.D. excuse my English is not very good.