Smart Trashcan

Our project is to create a smart trashcan: it opens when someone is detected in front of it, and shows the user when the trash is full and needs to be emptied.

Machines:

• Laser-cutting machine
• 3D Printer

To build the trashcan:

• 3mm MDF panel (at least 80*60 cm)
• PLA for the 3D printer

• 1 Arduino UNO
• 2 LED (two different colors)
• 1 Ultrasonic Sensor HC-RS04
• A laser
• 1 Photoresistor LDR
• 1 Servo motor Servomoteur FS90

• Screws
• Cables (for the Arduino)
• Tape
• Wood glue

Building the box:

The first step is to cut the different panels used to build the trashcan by using a laser-cutting machine. We use the file decoupe_boite.dxf which can be found at the bottom of this step.

Once we have all the panels cut, we can put them together thanks to the notches, as shown on the schematic drawing.

Before building the bin we drill several holes on the "BACK" panel : two at the top to fix the two hinges later and one at the bottom to power the arduino.

We use wood glue to hold together the different parts of the trashcan.

Building the false bottom

In order to hide the arduino, we build a false bottom for the bin. We also make it in MDF using laser-cutting and the following file decoupe_faux_fond.dxf.

We fix the 4 wood cleats with glue on the 4 corners of the box and we place the false bottom on them.

The bin lid is made by 3D printing, using the following file : Couvercle.stl.

We use two 3D printed hinges to fix the lid to the bin (file charniere.gcode).

Opening the bin

An ultrasonic sensor is used to detect if someone is close enough from the bin. Then the servo motor opens the lid.

Detecting if the bin is full

A laser and a photoresistor are used to detect whether the bin is full or not. If the intensity measured by the photoresistor is too low, the bin is full. The two leds are used to show the state of the bin.

These functions are controlled by the arduino. The code can be found below.

Sensors, servo motor, laser and leds

In order to set up the servo motor, we fix a wood support at the top of the bin. After fixing the servo motor we add a piece of wood used to lift and open the lid.

The laser and the photoresistor are placed in front of each other, high enough in the trashcan to detect if it's full. We put the ultrasonic sensor on the front of the bin and the two leds in the corresponding holes.

Once every sensors are placed, you can connect them according to the electrical diagram showed in the previous step.

Arduino

Put the Arduino (and the bread board if you used one) at the bottom of the bin, and hide it with the false-bottom.

Your trashcan is done!

Soooo clever, isn't it?