Smart Fridge and Shopping List

Introduction: Smart Fridge and Shopping List

With the smart fridge and shopping list you can monitor your shopping habits. You can make your shopping list so you just have to open your phone while you're in the grocery store. This project can also be applied on a closet or drawer.

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Step 1: Materials


  • 4x Load cells 5kg-10kg*
  • 4x hx711*
  • mcr012 barcode scanner
  • 2x ledstrip ws2812 (144 leds)**
  • 1x ultrasonic distance sensor - HC-SR04
  • 1x Green led
  • raspberry pi
  • arduino
  • power supply 5v
  • Capacitor 1000µF, 16v
  • 2x 4m utp-cable


  • fridge
  • 1x thin plastic plates
  • 2x plexiglass plates*
  • 2x hard (non-bendable) plastic plates
  • 1x box that fits your raspberry pi, arduino, breadbord
  • 1x box that fits your barcode scanner
  • double sided tape
  • silicone
  • M4 and M3 screws

* this depends on how many shelves you have inside your fridge
** this depends on how many shelves and can be used instead of the green led

Step 2: the Top Box

Required parts :

  • arduino
  • raspberry pi
  • breadboard
  • big box
  • screws

Required tools

  • Drill

We'll start of easy with the top box. This is the box where your arduino and raspberry pi will be placed.

p.s : I recommend to have a case for your arduino and raspberry so you won't damage them

  1. Take your Pi and arduino out of their case
  2. Place the two cases in the same corner of the box
  3. Drill 4 hole trough the cases and the box, note that they will need to fit an m4 screw
  4. Put the m4 screws trough the holes and tighten them with fitting bolts
  5. At last you need to make the breadboard stick to the box this can be done in 2 ways :
    1. if you have a metal base, you can take a metal drill and drill 4 holes in the metal so you can use screws
    2. take off the back sticker and stick it on the box

Step 3: Solder

Required parts :

  • 2x ledstrips
  • 4x loadcells
  • led
  • ultra sonic sensor
  • 2x 4m utp-cable
  • Heat shrink tubing

Required tools :

  • soldering iron

You can almost build the circuit but first you'll need to solder the components to a utp-cable so you have cables that reach the top. Make sure to keep a piece of paper with the color codes;

A short toturial on how to solder : How to solder in 5 easy steps

  1. Take the 2 utp-cables and cut them in half
  2. Take 2 loadcells and solder the piece of cable, 2 times
  3. Take the ledstrips and solder them to a piece of cable
  4. Take the led and ultra-sonic sensor and solder it to a piece of cable

Step 4: The Circuit

notes :

connect the 2 ledstrips to the power supply

connect arduino with pi by usb

connect mcr012 barcode with usb to pi

Step 5: Mysql

forward engineer this schema so and you have your database al set up

export this file into a dump file open the dump file and copy the code


Step 6: Install Your Raspberry Pi

first install raspian stretch : Raspbian stretch

then use following commands listed in readme file

you remove the whole project1 file by using

rm -r project1

if you did this on your pi you can clone tis repo :

git clone

go to maria db and past the code we had from the dump file

Step 7: Making Load Cell Structure

Required material

  • hard plastic plates
  • plexiglass plates
  • thin plastic plates
  • soldered loadcells
  • screws

Required tools

  • drill
  • saw and knife

  1. cut the thin plastic in 4 little pieces
  2. cut the hard platic plates so they fit in your fridge schelves
  3. cut the plexiglass plates smaller so they can go on top of the hard plastic without touching the edge of the fridge
  4. put one piece of thin plastic on each side in the middle of the hard plastic and drill the holes
  5. put the screw trough the load cell and tighten
  6. mark the holes on the plexiglass so they allign with the other side of the loadcell drill these holes
  7. repeat

Step 8: Barcode Reader

required materials

  • barcode reader
  • small box
  • screw

required tools

  • silicone
  • drill

  1. drill 2 holes in the bottom of the box and tighten the barcode reader to the bottom with a screw
  2. on the lid of the box put silicone and stick this to the side of the fridge
  3. let this dry for a night

Step 9: Ledstrips

Required materials

  • ledstrips

Required tools :

  • double-sided tape
  1. put the double sided tape on the back of the ledstrips and fit these into your fridge above your shelves

Step 10: Ultra Sonic Sensor

required materials :

  • small electric box
  • ultra sonic sensor
  • green led

required tools

  • drill
  • knife

  1. take the small electric box and cut 2 hole in the lid
  2. make a third in the top right corner of the lid small enough so your led fits just trough
  3. the last hole is on the side so you can put your utp cable trough
  4. apply this to you box on the bottom of your fridge

Step 11: Finish

run both project1-flask and project1-sensor and you are good to go

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