 I'm an engineer and this is the TI Launchpad. Now about a month ago, IEEE Computer Society here at the University of Texas at Austin had a Launchpad competition that was sponsored by TI. They handed out free Launchpads and they had a competition of who can implement a security system based on a knock pattern, so like a super secret knock like that. So this is our solution that we came up with. We won the competition, we actually not won, we slaughtered the competition. We won by 43 points. There's a couple of links below that you can look at the contest packet that has like the rules and all the problem statement on it and you can look at the point layout. Now our system is based on Launchpad and so instead of having a microphone for knocks, we just use this button right here so it registers the knock as a rising edge on the button. So when you press the button, it's like the moment you hit the door with your fist and so we'll go ahead and run the program. And so on boot, the system is locked, so red LED means locked and it's armed. So you have to put in the password so that your users can use the password and unlock the door. So you have to put the admin password in to set the user password. So we'll put the admin in. So admin password's entered. Now it's saying the red and green alternate flashing and it's basically saying, hey, put in a password for the users. So we'll do three quick, pause three quick. So now it's locked again. So let's say your employee comes up and wants to unlock the door. Green light's unlocked and then it waits for 15 seconds or so and then it puts it back over to locked again. So we can do that again. Locked locked. And that's about it. The program is a bit rough, see if I can pull up main. It's only in one file. It's a little dirty. Basically everything happens in the timer interrupts, which is not the best way. It's kind of like a pseudo state machine without the state machine part. It just runs a whole bunch of if statements. If I was able to redo this, I would put everything into a proper state machine, but we only had three hours to do so and it doesn't matter because we won anyways.