On 14/01/2021 13:46, Theo wrote:
> Ahem A Rivet's Shot  wrote:
>>          One cell and a DC-DC converter to give you a regulated supply,
>> monitor the cell so you can shut down (well) before there's too little to
>> run the converter.
>
> Which is all very nice, but is not what the OP is doing.
>
> They're monitoring *the input rail of the Pi*, because that's all the Pi
> hardware does.  You put 5V in, it tells you if it sags below some threshold.
> You don't get to put some other voltage in to test.  If you put in your raw
> cell voltage that will under- or over-volt the Pi and it'll either not work
> or fry[1].
>
> If they want to monitor some other voltage, they'll have to start from
> scratch because none of what they're doing (hardware or software) will work.

and the point is that any regulated supply will simply die without
warning, so they will have to

>
> Theo
>
> [1] the main SoC has some protection as it has its own voltage regulators,
> but USB-side things do use that 5V directly and you may fry it that way
>


--
Those who want slavery should have the grace to name it by its proper
name. They must face the full meaning of that which they are advocating
or condoning; the full, exact, specific meaning of collectivism, of its
logical implications, of the principles upon which it is based, and of
the ultimate consequences to which these principles will lead. They must
face it, then decide whether this is what they want or not.

Ayn Rand.

--- SoupGate-Win32 v1.05