This seem to be a neat little concept :)

Two big concerns however, as I am up to design a industrial control gear that must not do anything bad...

There need to be

  1) Verification of all data and commands over the serial channel (CRC or whatever and resend etc)

  2) Program verification at over and under normal operation voltage.


The 1) need to be in the bootloader, 2) in my own code, which will stop the machine and jump to bootloader if error in Flash checksum.  (this I will do anyway in my own code every time after reset, controlling the power supply while doing checksum or CRC of the program)

As my device will be pretty unreachable it would be very nice to use the existing vires, which are unshielded, but by using RC filter, schmidt-triggers, and solow RS232, that will work mostof the time, but I feel unsafe anyway without CRC or something of the data, as this is industrial, and there might be severe EMI.  I hate to have some instruction altered, may possibly injure somebody badly... (well there are manual emergency stops, and hardware autostop, but...)

See it as a suggestion
Keep up the good work
Regards
/Morgan