If your mqtt config is either not right (e.g bad hostname), or your broker goes down, the board's activity light remains on forever (I'm presuming it's stuck). The only way to resolve the latter issue is to power it off and back on again once your broker is back up (or figure out the config is wrong for yourself).
If your mqtt config is either not right (e.g bad hostname), or your broker goes down, the board's activity light remains on forever (I'm presuming it's stuck). The only way to resolve the latter issue is to power it off and back on again once your broker is back up (or figure out the config is wrong for yourself).