This Instructable is for making an alarm system using scratch, and a PicoBoard.
The link to the scratch program that will be used is https://scratch.mit.edu/projects/97054537/
The link to the video of it working is https://m.youtube.com/watch?v=SE7RlXzTh0Y
This worked for me, but know that this isn't guaranteed to work. Only use this as something for fun.
Please note that I'm not responsible for any failures of the system or any damage caused by the system.
This is my first instructable, so please let me know how it is and vote for it.
Step 1: Gather Materials and Tools
You need these materials:
Empty drink can
Basic insulated wire (amount depends on how long the doorway is away from where you are keeping the computer)
Micro USB to USB cable
PicoBoard resistance sensor (usually comes with a PicoBoard)
You'll need these tools:
You can get a PicoBoard and Wire for about $50 dollars so you can reuse both, which makes it a better purchase.
Step 2: Cut the Can
In this step be careful! The edges of the cut can can be sharp so make sure you don't cut yourself! Follow the steps for the first five pictures. After that when the top and bottom of the can are removed, make a series of small and close folds to flatten out the metal. Cut two pieces like shown in the last picture. Make sure that the two pieces are identical, this is very important for later.
Step 3: Bend and Cut Grooves
When you have the two pieces of metal, put them in the doorway you will set them up in, and fold one of them at the end of the doorway so it has a curve that is a little bit less than 90 degrees. Make four cuts of each piece, for the bent one, where it bends on both sides and for the flat one, line it up with the bent piece and cut two cuts at the same area as the bent one on both pieces. Bend the four pieces of metal back and forth until they fall out. The finished pieces should look like the ones in the pictures.
Step 4: Bind the Two Pieces Together
Use a bag tie to keep the two pieces together. Fold one around the grooves, and secure it like shown. Cut off any extra pieces. Make sure that the part of the bag tie that you have twisted is on the side of the bend.
Step 5: Make Two More Grooves and Add a Small Rubber Band
Make another series of cuts about halfway on the part of the hinge that will stick out of the door. Follow the same procedure of bending the pieces of metal until they fall off. You should have something like shown in the second picture. Now add a small rubber band in the grooves. It will likely be too big so the next steps will fix that.
Step 6: Shorten the Rubber Band
To shorten the rubber band, take a small, thin, and sturdy piece of a straw, and insert it under the rubber band. Twist it once or as many times as you need to to get the rubber band to fit nicely. Put the straw under the bag tie. Secure the straw with masking tape to the hinge. After the last picture, I cut off some extra straw, so the door would be able to close.
Step 7: Attach the Hinge to the Doorframe.
Use a piece of masking tape to attach the hinge to the doorframe. Add any extra masking tape if the straw isn't holding down.
Step 8: Attach Wiring to the Wall
Measure the wire from the hinge to where you will keep your control station (computer and PicoBoard). You'll need to cut two pieces of wire that long. Tape the wire to the wall. Use bigger pieces of tape and use them more often if the wire keeps on falling down.
Step 9: Attach the Wires to the Hinge
Attach the wires to the hinge using masking tape so it looks like the pictures.
Step 10: Hide Wiring (Optional)
You don't have to but I covered my wiring with a painting so it looks nicer.
Step 11: Set Up Control Station
Set up the PicoBoard like shown and go to this website ( https://scratch.mit.edu/projects/97054537/ ) to get to the scratch program. Make sure that Adobe Flash Player is installed and the correct drivers are installed for the PicoBoard. In my browser I had to click a special brick in the URL box for it to work properly. I also hid my control station in a cabinet.
Step 12: Enjoy!
Make sure you know how the program works, press the H key on your keyboard to show/hide a help menu on the program. A link to a video of the alarm working is here ( https://m.youtube.com/watch?v=SE7RlXzTh0Y ). If you can use scratch you could also turn this into a bathroom timer or other things.