RE: CAN Inspector: a CAN node to sample the CAN bus waveforms

I can imagine the "should work on Antarctica" bit on the specification list
can be quite daunting when you think about it ;-).

Without being encumbered by the experience of having to make stuff that
should work when it's that cold, my primary worry would be making sure that
the relays don't malfunction, because if one of them sticks "on" you have a
potential short circuit in the CAN bus, which will definitely render it
inoperable. You are probably in a better position to have information on
component reliability in those conditions, but I would factor in an
interlock (software or hardware) that prevents both relays being on at the
same time.

The second worry is capturing useful data, which is (as far as I am
concerned) mostly clever software. At first glance, the ADC supports a
circular buffer mode, so combined with the CAN interrupt on the MCU you
should be able to implement a triggering mechanism. I would ensure that all
CAN IDs on the bus are regularly sampled, as well as keeping statistics
ensuring that all messages that should be there are indeed present (a split
network can be reasonably healthy on the physical layer, but not on the
functional layer).

I'm mostly a software guy, so I'm not in a position to comment much on the
hardware. I'll leave that for the specialists.

cheers,
Bram

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