I have two flipsky VESC 6.6 (https://flipsky.net/collections/electronic-products/products/fs-esc-6-6) that I think was killed by over current into the RX/TX pins. The VESC was connected to an arduino, which has a complicated and dasiy chained path to common ground with the VESC. I did not have a grounding pin between the VESC and the arduino. When I accidentally turned the power switch off, I think that somehow caused a voltage differential between the arduino and VESC that caused an excessive amount of current to flow through the Arduino and VESC RX/TX pins (both the arduino and the vesc died).
Looking in the schematic, it looks like the TX/RX pins go directly into the STM32. Am I correct to assume the STM32 is dead? Am I correct to expect that this should be fixable by replacing the STM32 chip (and flashing firmware on it)?