A shared repository to provide a description of reverse-engineered glucometer protocols

View the Project on GitHub glucometers-tech/glucometer-protocols

FreeStyle InsuLinx

Reverse engineered by Xavier Claessens.


This device uses the shared HID protocol used by other meters in the FreeStyle family. All messages that have been identified are considered text commands and use message type 0x60.


All commands supported by the shared protocol are supported by the device. Those that deviate from said protocol are here documented.


The $result? command is used to dump the readings records from the device, and it follows the Multiple records command output format as described in the shared protocol documentation.

The first field in the record specify the type of record; type 0 is a blood glucose reading.

Blood glucose record fields

  1. type = "0"
  2. id
  3. month = 1*2DIGIT
  4. day = 1*2DIGIT
  5. year = 1*2DIGIT
  6. hour = 1*2DIGIT
  7. minute = 1*2DIGIT
  8. unknown
  9. unknown
  10. unknown
  11. unknown
  12. unknown
  13. unknown
  14. value = 1*DIGIT

    Unknown (but likely) whether this includes HI / LO constants.

  15. unknown
  16. unknown

Other commands

The following commands appear to also be supported, but their meanings are not known: