For week 10, I wanted to pretty much finish fabrication, and while I got close, there are still a couple of things that need doing.
I started out by finishing up my lock cylinders. They just needed some attachment points for servos, so I drilled holes in them and used JB weld to put eye hooks in them.
While that was going on, I tried out attaching metal panels to the box. Using a combination of caulk glues, they become very secure.
Next up, I started work on the door hardware. I put my cylinders in place, and rigged them up to servos. After shuffling a few libraries around in raspberry pi, I finally got a library that supported pins with servos (pigpio).
The servos are fixed in place with a combination of physical fasteners, hand crafted, and glue.
After adding the other servo and playing with the code, I realized that the library I was using for the servos was not very robust. That is, it lacks specific commands. I tried to time the servos on and off by milliseconds in order to open and close the pins, but that failed. I instead took a sensing route, and added some home made location sensors.
The sensor is just two leads sticking out. When the pin makes contact with the leads, a circuit is completed and the raspberry pi stops spinning the servo. Then to “lock” the pin, the servo is run a set amount of time to provide a certain amount of movement.
Finally, I had all the pieces in place. I hooked up both sensors and servos, and modified my code I used for my LED twilio example. And eureka. Servo motion triggered by an SMS.
That pretty much completed the door, I only needed to fasten all the components in place, and put holes in the frame for the pins to fit in.
Finally, I finished fabricating my last interior panel by trimming it down a bit and putting the lights in it. I needed to solder up a barrel jack connector to the light strips in order to provide them a safe ample power source.
Time Management
I didn’t have real concrete goals this week. I just knew what needed to be done and I did it. I lost track of time spent, however, I guess it is in the neighborhood of 14-18 hours.
There are just a couple of things that still need to be done to finish the box itself, but I predict I can be project completed by next week and deployed Sunday or Monday.
ATLS Capstone 