decoding-contour-next-link

Space to collaborate on decoding Contour Next Link comms protocols, and the piggy-backed pump comms

Getting Started

• Make sure you have python and pip installed
• Clone this project
• Install the dependencies:

$ sudo -H pip install requests hidapi astm transitions PyCrypto crc16 curses python-dateutil

• Plug in your Contour NextLink 2.4 USB stick
• Run get_hmac_and_key.py to get your HMAC and AES key for your USB stick serial number. This script takes one argument, which is your CareLink username. The script will also ask for your password - this is not echoed out or stored at all.

$ python get_hmac_and_key.py my_carelink_username  
Enter the password for the CareLink user my_carelink_username:
HMAC for serial 1055866: e28fe4e5cf3c1eb6d6a2ec5a093093d4f397237dc60b3f2c1ef64f31e32077c4
KEY for serial 1055866: 57833334130906a587b7a0437bc28a69

Now whenever you run read_minimed_next24.py, the script will get the config from the config database and communicate with your pump.

$ python read_minimed_next24.py
# Opening device
Manufacturer: Bayer HealthCare LLC
Product: Contour Link USB Device
Serial No: 0000000001055866
# Request Device Info
# Read Device Info
6213-1055866
# Request Open Connection
# Request Read Info
# Negotiate pump comms channel
Negotiating on channel 20
Negotiating on channel 20
Negotiating on channel 17
Negotiating on channel 14
# Begin Extended High Speed Mode Session
# Get Pump Time
Pump time is: Sun, 01 May 2016 16:49:59 +0000
# Get Pump Status
Active Insulin: 0.450U
Sensor BGL: 340 mg/dL (18.9 mmol/L) at Sun, 01 May 2016 16:47:21 +0000

Known Issues

• Assumed pump time was in UTC, but this doesn't ring true for non DST times (in Melbourne, anyway)
• Currently uses curses.ascii, which doesn't work on Windows.