The dexcom package provides functions to connect to Dexcom G4 and
Dexcom G4 Share continuous glucose monitor (CGM) systems.
It connects by either USB or Bluetooth LE to the Dexcom receiver.
For BLE connections, the serial number of the Dexcom receiver
must be passed in the DEXCOM_CGM_ID environment variable.
For the initial connection to the receiver, use the Settings > Share menu
to Forget Device, then turn Share back on.
The cmd/g4ping program can be used to confirm connection with the receiver.
For serial connections, the host must have the cdc_acm kernel module loaded.
Look for the creation of /dev/ttyACM0 in the system log
when the receiver is attached.
The cmd directory contains some simple utility programs:
g4pingpings the receiver (first connecting if necessary) and exits with a success or failure status.glucoseretrieves CGM data and prints it in various formats.backfillfinds gaps in Nightscout CGM data, retrieves the missing data from the receiver, and uploads it. Note that a USB connection works much faster for gaps that are hours or days in the past, and can be done from any Linux machine, not just an OpenAPS rig.g4setclocksets the receiver's date and time.g4updateretrieves CGM data, with options to update a local JSON file and upload to Nightscout.