Power board 4.2 firmware shipping

[Jeremy Morse]

Hi,

There's currently an updated power board firmware in a position to be
shipped at teams, but not in the form of a general rollout. The new
features, mostly mentioned here by me already:

* Higher whole-board current limit
* Output specific current limits
* Board reset on USB reset
* Piezo firmware support

Rob detected in QA that the watchdog is going to reset during
reflashing, and it can't be turned off for flashing, so that can't be
shipped this year.

More of a problem: while all our boards can be forced into a mode where
they can be reflashed after some kind of interruption / flash-failure,
it turns out this isn't the case for the power board. The bootloader
does not turn the 5v rail on; the odroid doesn't turn on; and nothing
gets flashed.

This can probably be fixed with a future bootloader via various
shenanigans, the real crux of the matter is that the odroid can't be
allowed to drain the battery, and managing the battery isn't something
the bootloader should / could be doing.

The result is that flashing the power board becomes a more critical
process, one that will unrecoverable wreck kit if shipped out to unlucky
people. It's an acceptable risk if the person operating the kit is aware
of the flashing process, and knows not to interrupt it. I've just tested
this on the phone with CLY, and the board flashing process there was a
success.

The solution (suggested by Rob) is to use the team-specific robot.zip
facility of the IDE to ship updated power board firmware at teams who
actually need it [0]. I've configured it (enjoyably easy) to serve
updated firmware at only CLY for the moment. I'll post on the forum in a
bit to let teams know what's happening, and so that they can request the
new firmware.

[0] These are the people who are affected by the 10A current limit.

--
Thanks,
Jeremy