Hi,
I'm with the London Hackspace, and we run a number of 3d printers that member can use. Each printer has its own raspberry pi running octoprint.
We require members to do an induction on the printers before they are allowed to use them, and for these and other restricted tools we have a system of Access Control Nodes (ACNode) that we have developed, you put your card (the same one you used to get into the building) into the slot, if you are authorized on that tool then it is enabled and you can use it, if not you can't.
Now in the past we simply controlled mains power to the printer itself, which is simple but has some disadvantages, so I am looking at alternatives. One would seem to be to have the ACNode connected to a GPIO pin on the pi and have it control Octoprint directly, perhaps through the pause button functionality?
Using the pause button would have the advantage that if a member had to remove their card for some reason during a print, they could resume when they put it back in.
An important consideration is that so long as the ACNode does not contain a valid card, printing cannot happen.
Any thoughts on this?