When I connect a 3 foot USB cable at the "micro B" end into my Arduino board (Adafruit Feather 32u4 with the ATmega32u4 3.3 volt chip) sometimes the system malfunctions and subsequently resets. The symptom of the malfunction is that the LCD graphics is messed up. "Sometimes" means less than 10% of the time.
This was observed in a cold plug situation where the "standard A" end was loose. It was also observed when the standard A end was connected to a cellphone wall charger. In a programming situation where the standard A end is connected to a computer it is uncertain whether this was observed.
I noticed most of my USB cables do not have ferrite beads. They are mostly cellphone charging USB cables. I have one USB cable with a ferrite bead but it is not suitable for Arduino use because it has a "standard B" end.
This is what Wikipedia says...
Ferrite beads are one of the simplest and least expensive types of interference filters to install on preexisting electronic cabling. For a simple ferrite ring, the wire is simply wrapped around the core through the center, typically five or seven times. Clamp-on cores are also available, which attach without wrapping the wire: this type of ferrite core is usually designed so that the wire passes only once through it.
This description suggests there is a difference between a built-in bead and a "clamp-on core" but I do not know how to assess whether this difference is important.
Should I buy a snap on ferrite bead for my purposes or should I simply replace the cable with a proper ferrite USB cable?
