Mailbox by Aisling Frugoli, Isabella Saavedra, and Cam Fernadez

The Circuit Playground Express is a device built by Adafruit that has capabilities to show lights and play sounds. The CPX can be battery-powered and can be attached to the servo motor to control the movement. Our CPX design is a mailbox made out of 3D-printed parts. The parts are 3D printed on PLA material using MakerBot SKETCH printers. The device is built using a CPX, and a servo motor, and is battery-powered. The CPX will play lights and play sounds, which are activated by at least 3 different sensors or buttons.

All necessary supplies and equipment are provided with links. Photo(s) of the supplies are shown

Ex:

• Adafruit Circuit Playground Express Basekit
• Thingiverse 
• Tinkercad
• Circuit Python
• MakerBot SKETCH
• PLA Material
• Batteries
• Battery case
• 180-degree rotation Servo Motor
• 3 screws
• Philips head Screwdriver
• Hot glue gun and glue

• Download the following STL files from Thingiverse and import them into TinkerCAD 
• mailbox-flag.stl 
• mailbox-back.stl 
• mailbox-back.stl 
• mailbox-bottom.stl 
• mailbox-front.stl 
• Mailbox-case.stl - this file will need to be printed with supports 
• cpx-mount-simple.stl 
• In TinkerCAD, change the sizing of the case, the front, the bottom, and the back. The width of each of these pieces needs to be increased by 12.4 millimeters so that the bottom of the mailbox matches the width of the CPX case. So, the bottom should have a width of 54.4 millimeters, the front, and back pieces should have a width of 58.20 millimeters, and the case should have a width of 54.40 millimeters. 
• Export these TinkerCAD files to Cloudprint and print them on a MakerBot SKETCH 3D printer using PLA Material. Not all of the files can be printed together, so you will need to do three separate prints. The Flag and the Case can be one print, the front, and back are another print, and the bottom and the CPX case are a final print. 
• Once the prints have finished remove them from the print plate and assemble the mailbox. 

• In TinkerCAD, make a hollow rectangular box that fits the width of the bottom of the mailbox. 
• The width of the mailbox bottom is 54.4 millimeters
• Along with fitting the bottom, one must make sure it fits the battery case inside 
• Take the measurements of the battery case and increase them by a few millimeters in order for the battery case to slide in well
• Export the TinkerCAD file to Cloudprint and print it on a MakerBot SKETCH 3D printer using PLA Material. 
• Once the print has finished remove it from the print plate and attach it to the mailbox with hot glue.

1. Assemble the bottom of the mailbox and the case. Slide the bottom of the mailbox into the ridges of the rounded piece of the mailbox. 
2. Assemble the back of the mailbox. Pop the sides of the back of the rounded mailbox piece into the ridges of the back of the mailbox. The back of the mailbox has an extra flat piece on the top. This may take some strength, it is a tight fit! 
3. Attach the servo motor. The servo motor gets popped into the hole on the right side of the mailbox. The wires of the servo motor get threaded through the rectangular hole in the back of the mailbox.
4. Screw on the flag and screw the servo motor into place. Using one screw, screw the flag into place. The flag gets screwed right into the white movement part of the servo motor (the gear). Then screw two screws into either side of the servo motor. The screws go into the small holes on the right side of the mailbox, and crew into the servo motor inside the mailbox.
5. Put the front of the mailbox on. Snap the front of the mailbox onto the rounded part of the mailbox.
6. Your mailbox is now assembled

• After the servo motor has been put into the mailbox, it needs to be soldered to the CPX
• Plug the soldering tool into an outlet, and give it time to warm up
• Once the soldering tool is heated up, grab your CPX and your servo motor. If your servo motor does not have exposed wires, you will need to expose parts of the wires. Use pliers to remove the rubber casing from around the ends of the three servo motor wires
• Once the wires have been exposed, wrap the exposed ends of the wires around the CPX in the VOUT, A1, and GND holes
• Now, grab a metal coil, and melt the wires of the servo motor onto the CPX to make the strong connection. 
• Don't put too much metal though, because the CPX still needs to be able to fit into its casing. 
• Once you are finished, unplug the soldering tool

• Open MakeCode and begin a new project 
• In this project, add the following codes 
• "On Loud Sound" from Input, and "Show Ring" from Light 
• "On Shake" from Input, "Set Servo A1 angle to 90" from Advanced, and Servos 
• "On Button A Click" from Input, and "Play Sound Ba Ding" from music
• Then download the code onto your computer 
• In your downloads folder, drag the downloaded code onto your CPX - make sure your CPX is plugged into your computer and titled "CPLAYBOOT", otherwise, it will not work 
• When the code is downloaded onto your CPX, unplug it from your computer and plug it into your battery 
• Ensure your code works by making a loud sound, shaking it, and pressing button A
• If your code does not work, troubleshoot it in MakeCode and make adjustments as needed

• Follow these instructions to install CircuitPython onto your CPX: https://learn.adafruit.com/welcome-to-circuitpython/installing-circuitpython 
• Connect your CPX to your computer and save code.py onto it
• The provided code will:
• cause the motor to rotate clockwise when button A is pressed
• cause the motor to rotate counter-clockwise when button B is pressed
• Light up when you shake it