I am just about to start connecting my Daisy chained G2 18v15 Motor Controllers to my Arduino, and I’ve been able to wrap my head around most of the Motor’s manual, but I’ve encountered this in my many readings, and still don’t fully understand what it means or what risks are involved, and haven’t been able to find an answer on the web or with a forum search:
Unpowered devices with a TTL serial port can turn on or partially on, drawing power from the serial line, which means that extra care must be taken when turning power off and on to reset the devices.
8 x G2 18v15 Motor Controllers, split into two Serial groups with 4 on each daisy chain. The daisy chain connects all optional Serial TTL lines (Rx,Tx,Txin,err,rst,gnd), and the controllers are powered by an external 12V Switching Power Supply (aprox 500W PC ATX power supply).
I’m running an Arduino Due for this project, and I intend to also power it with the same external 12Volt supply.
The motor controllers are wired to common ground in the daisy chain, to the Arduino, both of which are mounted on 3D printed plastic and isolated from the frame, which is aluminum, and which isn’t grounded (yet) with the external 12Volt supply. The power supply is connected by a series of 14 AWG wire pairs running in a parallel bundle for about ten feet to the actual frame, and then are only connect directly to the motor controllers currently, and the Arduinos 12 volt barrel plug. I would gladly take advice or links to a good tutorial on grounding.
For now, I’ve only used the Arduino on USB power, and haven’t connected the Motor Controllers serially. However, I started to plug in the ground to the Arduino last night, and I swear I heard something pop, so I stopped. I checked out the Arduino and ran it with USB, and everything seemed to be okay, so I’m not sure if maybe I just heard something else or I actually had a close call. And because I don’t understand this pop-out from the manual, I’m going to refrain from connecting anything else until I figure it out.
Any insight or advice would be greatly appreciated