A couple of basic Blinkt questions

Hello there, I think I have developed a bit of a “Blinkt-habit” ;)
I do have a couple of questions I would like to ask though:
1 - what is the MINIMUM setting that can be used with the set_brightness command ?
I can go as low as 0.05, but no lower (eg. 0.02), they just don’t light below 0.05. Just curious really, I guess a diffuser could be added (I’m using a number with MQTT and bash scripts calling netcat to monitor various Raspberry Pi devices, so they’re on all the time)
2 - is it possible to use the GPIO pins for anything else once the Blinkt’s installed ? What drives this question is wanting to put say a momentary contact switch across a couple of pins to trigger a shutdown without having to log into the device.
I have simple code that will do this, and the choice of pins is fairly flexible, but I don’t understand which of the GPIO pins the Blinkt is actually using.
Many thanks in advance for any assistance - and thanks for including the MQTT sample code, it’s kicked off a very interesting chain of projects !!

1 - no idea, but I suppose at some point the current going through the APA102s is just not enough to have any (noticeable) effect. That is certainly true for other types of of RGB LED, so I suppose that there is a theoretical limit, which you may have found.

… that said, I’m not quite the expert, but @gadgetoid posted this in relation to another product that uses APA102: https://github.com/pimoroni/mote/issues/19

  1. sure, just don’t use bcm23-24, used by Blinkt, as seen here.

Note that we recently put together a non-python based clean shutdown utility/daemon that does what you want. Obviously that does not mean you should use it, just nothing its existence: