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By RichardS
#43126 User
Samsungite

Description
I think that one day, all food cupboards & fridges/freezers will be smart. All products will have an RFID or video recognisable label which will update a list of product usage. Your local supermarket will gather this information & replenish your products as required - who knows ??
I can now check how much milk I have on my smart phone while out shopping !!
I use a load cell connected to an Arduino which displays the quantity of milk on an oled display and transmits the same information via wifi (ESP8266) to the web (Thingspeak).
The information is updated each time the fridge door is opened - I use a magnet and a reed switch to facilitate this.
Circuit
There are very few connections - they are listed in the code !
// oled SDA #A4
// oled SDC #A5 NOTE Supply is 3.3v

// HX711.DOUT - pin #A1
// HX711.PD_SCK - pin #A0 NOTE Supply is 5v

//ESP8266 TX/RX to arduino RX/TX
// Reed switch connected to interrupt on D2 normally Gnd - goes high when fridge door opened

Parts
Arduino Nano
ESP8266
128X64 OLED LCD LED Display
10Kg Load cell + HX711
9v PSU

Links
Instructables

Video


Images
Attachments
(7.05 KiB) Downloaded 578 times
loadcell.jpg
esp_components.jpg
Thingspeak.jpg
ESP_Display2.jpg