[PLUG] Raspberry Pi portable UPS and speaker

[Mayuresh]

On Mon, Nov 16, 2020 at 11:02:35AM -0700, Arun Khan wrote:
> Perhaps a monitor with integrated speakers and mic?

No, this is a headless setup, just speakers and mic. Currently I have
attached wired ones - a bit untidy and location restricted, but
functional.

> Search "computer speakers with microphone" on Amazon/Flipkart -- many
> of them are BlueTooth.

Sure. I'll also need ones with BT dongle, such that that BT dongle is
supported. (Pi 3B has a builtin BT, 2 doesn't.)

> I haven't mucked around with UPSs for a while (> 5 years).  I recall
> some of the APC models came with a "special" cable that hooked into a
> USB port of the computer.  And the "apcupsd - APC UPS Power Management
> (daemon)" worked very well with it.  Make sure the daemon package is
> available for the ARM platform.  You will still need to tell the daemon
> which USB port to monitor.  DIY -- generic brands provide regular DB9
> serial port and you will need to build yourself a serial cable to hook
> up on the relevant GPIO pins.

Currently I have used a general purpose UPS and arranged to run the wires
up to the device. Was looking for a compact UPS. It doesn't have to have
220V outlet, just microusb. It doesn't have to have too much of backup
time - a few seconds till device powers itself down. I think capacitor
based ones fit the bill, but none seem available readily.

Second question will be of signaling to Pi through GPIO or USB.

As an alternative (or as a desirable feature even otherwise) I am trying
to make all the mounts readonly with noatime. For external disks (which
are usb sticks) this is done easily. Writes are infrequent for the usage
and mounts are temporarily changed to rw manually.

For flash card, this would require some work, though at least the risk is
greatly reduced as the card doesn't have much of a data. Tiny core Linux
for Pi may be suitable for this, as the card goes out of picture post
boot. A live CD like arrangement would be even better as it would be
resilient during the boot as well. For some reasons (skipping details),
though, I have chosen NetBSD. Will try and compile my own custom image for
a fully readonly setup which is safe to just switch off.

-- 
Mayuresh