[ScottFree]

You need a continuous glucose monitor, like Freestyle Libre or Dexcom. Here's a writeup of somebody that goes into detail about what's involved:

https://medium.com/@justin_d_lawler/continuous-glucose-monit...

The sensors aren't cheap. Last time I looked, you wore them for 1 week at a time and they were $80 a pop.

[GiorgioG]

The Freestyle Libre is good for 14 days at a time, and as far as I know costs $110-120 for a 2-pack. No it's not cheap, but it's not as expensive as the Dexcom. My son wears a Dexcom (type 1 diabetic) and my dad wears a Libre (type 2 diabetic.) The Dexcom is far more expensive, but it's the only one that will integrate with my son's insulin pump.

[pimeys]

And about 450€ per transmitter that lasts for three months. Using open source tools you can extend the sensor lifetime to 2-3 weeks and transmitter to 6-9 months and I advice to read on that and try tools like xDrip.