#1. DYNAMIXEL SDK.
- Use Dynamixel2Arduino rather than using DYNAMIXEL SDK through Arduino.
#2. In general, providing 12 V to the DC motor would not be very problematic, as DC motor just runs at the given power. But supply exceeding voltage over DYNAMIXEL specification generally ruin a MCU inside DYNAMIXEL. I am not sure which regulator is used in the XL330 series, but I think it could be fine if you supplied 12V to the DYNAMIXEL for temporary time.
Maybe your DYNAMIXEL’s firmware in MCU can be corrupted for the high voltage.
Please checkout if you can scan the DYNAMIXEL via R+Manater 2.0 with OpenCM 9.04. If it’s not scanned, I highly doughs that the installed firmware has gone bad.
In this case, perform the Firmware Recovery for the DYNAMIXEL with the OpenCM 9.04 in R+Manager 2.0.
Note that if you uploaded arduino code to the OpenCM 9.04, you have to do Firmware Recovery to your OpenCM 9.04 first.