Point of Sale Arduino Board Integration

Projects General Guidance
1

Hey everyone! I currently want to make a "smart" scale project. I am wondering if there is anyway to connect an arduino board to an existing point of sale scale. The type of scale that you find next to a register in a grocery or butcher shop. Would it be possible to connect to the load cell with a HX711? Or would it be better to connect via one of the inputs in the scale. The scales typically use UART/RS232 so I'm wondering if there is anyway to connect that to the arduino board. Maybe there is another port that would work better?

Thanks in advance!

2

I can't help, but I'm curious to know what you actually mean by a "smart" scale.

3

I want to eventually try and make a food scale that connects to a database and automates itself as you weigh food. Kind of like a food tracker of inventory and sales.

4

I found this project RS232 to USB Converter With Arduino Due Or Mega 2560 - Copperhill Does anyone know if this would be sufficient to connect the arduino/scale combo to a database?

5

Anyone have any experience with this type of project? I got a suggestion to go with an Adafruit Feather with Wifi as I could connect to my store wifi network and then get the weight data from the r232 board to my arduino or feather board and relay this info to a mysql database.

6

Jsas:
...to connect an arduino board to an existing....scale...next to a register in a grocery...shop. Would it be possible to connect to the load cell with a HX711? Or would it be better to connect via one of the inputs in the scale. The scales typically use UART/RS232...

If you have a user manual that spells out the protocol, use RS232 and connect to the Arduino via a MAX232 or similar. Google it. Hacking an existing commercial (grocery-store-type) scale with an HX711 probably could be done but would be a PITA (and probably wouldn't be valid for trade).

7

For a store you might want to use the commercial scale.
RS232 voltages are handled by MAX232 chips as noted above.

You can connect SD cards to Arduino though I've learned that there can be issues with the cheap adapters ruining SD's. With SD you can put a ton of changeable data in your project.
Otherwise yes, it must communicate with the store PC and wifi will come up. Just remember that wifi is radio which is vulnerable even if just to "1337" kids out to get even with the world. Any target just to "look big" will do.

If the data changes rarely you can store it in the Arduino's flash memory along with the program.

Aren't you going to need a barcode scanner in there? Maybe a touchscreen for operator-interaction?