I just sent a print, started it, and cancelled it
Then I went to terminal command window, and typed "M112" and hit enter, and I didn't see an M112 command float dutifully up my screen as was my intention
So I typed "M112" again, only this time, I hit the "send" button, thinking that it might pay more attention that way
I still failed to notice an M112 float up my screen
Then, when it got to .5 degrees of the set temp, this happened
Recv: T:21.11 /0 B:84.50 /85 B@:255 @:0
Recv: ok 5
Send: N6 M11239
Send: N7 M104 T0 S038
Send: N8 M140 S0*109
Closing serial port due to emergency stop M112.
Changing monitoring state from "Cancelling" to "Offline (Error: Closing serial port due to emergency stop M112.)"
Connection closed, closing down monitor
It was like watching a movie where the hero is trying to defuse the bomb, then finally getting it at the last half second
I didn't try disconnecting the Raspi from the printer (which I didn't think would work, but I should have tried anyway), nor did I try unplugging the printer itself (which I knew would work, but, that wasn't part of the experiment)