Retail POS App | Scale Integration

We've implemented a scale integration for 'deli style' shops to increase your inventory accuracy, reduce theft, and speed up your checkout process.



  • Buy BlueSnap DB9-M6A Wireless RS232 Adapter.

    • “Adapter” - Male DB9
    • “Power” - we recommend Rechargeable Battery and Power/Charge Cable.
    • “Firmware” - BLE
  • Buy scale from Scales Known to Work with BlueSnap M6A Wireless RS-232 iOS list.

    • Buy any “Null Modem” or “Standard Mini Gender Changer” adapters as noted in this article to go with the selected scale.

      Make sure firmware for BlueSnap adapter is up to date. Contact SerialIO support to assist with this. Their support policy can be found here.
  • Download yACK BLE from the App Store

  • Must use Retail POS app 5.0.9 or above

  • Your product needs to have a category and be set to grams instead of units.

How to Set Up the Scale

1. Connect DB9-M6A to scale (with any needed adapters).

  • Connect power to DB9-M6A.
  • Connect iPad to DB9-M6A through bluetooth.

2. Open yACK BLE. 

  • Connect to Nearby BlueSnap DB9. Select after connecting, if necessary.
  • Switch to Command mode.
  • Send command “set UA B 9600”. This sets the baud rate at 9600bps.
  • Turn Scale on.
  • Configure scale settings
  • Go back to weighing mode on scale.
  • Put yACK BLE back into Stream mode.
  • Push Enter on the scale (or, Print for some scales).
  • Observe a weight value being displayed in yACK BLE.
  • Force close yACK BLE.

How to Connect Scale to BLAZE

1. Open BLAZE Retail POS app > Login

2. Click Scale Icon Upper right 

  • Connect Nearby DB9-M6A
  • Select default

How to Use Scale with BLAZE

1. Start a sale.

  • Select an item that is weighed on the spot (deli-style).

2. Weigh item.

  • Once weight has stabilized, push Enter (or, Print for some scales) and see weight be filled out in BLAZE app.