Well, FINALLY, the battery board is working. Next on the agenda:
"JennerGPS", which I believe has now officially stuck as a name. The
goal is to send this board off to OSH Park by Tuesday.

More details:

So, remember how everything was working - the BQ3060 was even claiming
that it was turning on the MOSFET gates, but for some reason the gates
of the P-Channel MOSFETs never went low? It's like the internal MOSFET
that were supposed to drive the external P-channel MOSFETS weren't working.

Seemingly COMPLETELY UNRELATED is the chemical fuse safety feature on
the BQ3060. If something goes horribly wrong, the BQ3060 can assert the
FUSE pin which blows a "chemical fuse" - essentially a fuse that can be
blow by a logic signal. That's an output, right? It asserts a signal? So
if you don't use a chemical fuse, you just leave that floating, right?

No. You don't. But you'd never know that, because it's a COMPLETELY
UNDOCUMENTED FACT that the "FUSE" pin of the BQ3060 must be pulled low
in order for the BQ3060 to be able to assert the MOSFETs. It's like it's
the drain connection to the P-channel MOSFET driver, or something. Found
this out on the TI forums because of course someone else had this
problem. Thanks, TI! :(


Andrew Greenberg

Portland State Aerospace Society (http://psas.pdx.edu/)
and...@psas.pdx.edu  C: 503.708.7711

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