JTAG, short for Joint Test Action Group, is a method used for boundary scanning. Possibly applications are hardware testing/debugging and firmware flashing, including debricking of hardware which ended up in a defunct state.
I have a bluetooth speaker. Infinity Fuze 100.
It's a good speaker.
But it has annoying messages on startup and shutdown. And for other interface events. I'd like to either get rid of them entirely, ...