I will be building a circuit to control a robot arm which is not a small toy kit. There will be motion sensors, feedback systems, robot arm controlling modules. So digital signals will be flying all around. The data communication will be over I2C.
The robot arm has 6 servo motors, 2 x Servo 5521MG (Running Current 750 mA - 1.2 A @ 6V), 4 x Servo MG996R (Running Current 500 mA - 900mA @ 6V) and their potential noise concerns me.
I am planning to use separate power sources but ground has to be common to pass the servo control signal.
I found some ideas such as using ferrite on servo cables, opto isolator, which one would be best option?
Which pcb design practices I should follow to prevent noise influence over signal lines?