Bluetooth door lock

What the day job lacked in money, it had in bluetooth modules, so it was time to whack together a sliding door lock. Of course, the actual bluetooth board was a trade secret. The servo was a 10 year old piece from the DVD robot. The H bridge was the remanes of the laser projector from 2011, which itself was made from the 72Mhz remote control from 2007.




It was finally due to be cut up. It needed a new voltage regulator circuit to supply 5V to the bluetooth board & 8V to the servo.

Bluetooth sliding door lock (1 min 30 sec)

You'd be amazed how complicated such a simple movement can be. In a robot, every movement has to be bracketed by sensors, with interrupt handlers, properly torqued cable winches, H bridges, manual alignment.

There are a lot of points which can go out of alignment. Glued as much of it as possible to keep it aligned. Bluetooth control used bits of software from the day job, with all the limitations. It can't scan for bluetooth peripherals for more than 10 seconds, so it needs to be restarted after going out of range.

Normally, the receiver & transmitter would have keys generated by synchronized random number generators. There is no random key generator, so all someone needs to do is capture the packet, but they'd have to be real desperate.

There are millions of bluetooth doorlocks, but none that are free & none that would work on a sliding door without massive destruction.