Good luck!<p>I tried to put a password on a device I contracted to do. Just the serial number, the installer reads it off and types it into their phone. Simple! Different for every device!<p>The manufacturer said Too much trouble for the installers! Just leave it open.<p>Sigh.<p>I compromised, made the bluetooth connection work for 10 minutes after power-up, give the installer time to connect (it wouldn't shut down as long as there was a connection), initialize the device.<p>See, now it wasn't 'open' for more than 10 minutes total. After that you needed physical possession of the device to connect again (power-cycle it).<p>They accepted that. It was something, not the same as security but at least the window of vulnerability was smaller.