[GTALUG] TIL: rtcwake / wakealarm

[Stewart C. Russell]

On 2021-04-12 9:28 a.m., D. Hugh Redelmeier via talk wrote:
> 
> I always thought that shutting down a Pi really left it on.  That's one 
> reason some people like Pi power supplies with a switch.  To what 
> extent is that true?

It does: it just leaves the processor halted. So the other peripheral
chips are still drawing power.

> How much power is saved?  I delayed sending this message, hoping to add 
> information about this but I'm just not getting to the experiments.

Not much, but then, a Raspberry Pi doesn't draw much even running flat
out. There are fancy Raspberry Pi add-ons that provide a proper
logic-controlled shutdown and poweroff, but they typically cost about
the same as a Raspberry Pi, or about two year's energy cost for running
a Raspberry Pi 4B flat out.

cheers,
 Stewart