Anubis – the G6 reborn!

In exciting news, Project Anubis has been announced. It is a modification to the Dexcom G6 “Firefly” CGM transmitter that gives a bunch of things that I personally see as advantages over new units.

  • User-replaceable battery (larger capacity than original). Unlike with re-batteried G5 transmitters, no fancy epoxy sealing is required. A tiny packet of Sugru/Kintsuglue can be carried with a spare battery, and even on extended travel away from civilisation can be easily replaced without fancy tools (with a waterproof seal when you’re done).
  • 180-day transmitter expiry. To cope with the larger battery capacity, the transmitter no longer stops after 100/110 days.
  • After replacing the battery, the unit automatically resets to day 0 and enters deep sleep, not chewing battery until inserted into a sensor.
  • For users of xDrip+, xDrip4iOS, Spike, etc the transmitter again sends raw data as well as the “cooked”/”Native” calibrated data. Just like the original G6 units.
  • No sensor restart detection. To extend the use of a sensor past 10 days no longer requires removing the transmitter or jamming BG strips into awkward positions, and praying you’d held your mouth right. They should be as easily restarted as G5 sensors.

The rest of it essentially is a G6 (although obviously not supported by Dexcom). That support only applied to the original unit before recycling. For that matter, they’re no longer “Medical Devices”: just pieces of electronics we choose to use…

Just like a standard G6 the unit does not require fingerprick calibration (although this can be used). The units work just like other G6s, using the same sensors and communicating with phone apps, pumps, standalone receivers, etc.

Visually different

As can be seen in this prototype image, an Anubis unit is marked (by laser engraving) to avoid confusion with a regular G6. The serial number is currently displayed on the top of the unit for convenience.

That is a security concern to me: a nefarious bystander who finds out your serial number could conduct a denial-of-service attack (just as with G5/etc) and disconnect your CGM from your phone/pump. But it’s easy to cover up with Sugru/enamel/etc to remove that risk.

Extended use

By default an Anubis unit will run a G6 sensor for 10 days with a 2-hour warmup, just like a standard Firefly. But for “advanced users” wanting more (and willing to take the extra steps of monitoring sensor performance) this can be tweaked via Bluetooth to provide sensor sessions up to 60 days (or whenever you give up on the sensor) with a warmup of just under an hour. Note that the Dexcom G6+ used in South Africa already has 14-day sessions and 1-hour warmup.

Project Anubis

Project Anubis is the culmination of over 6 months effort by a team of engineers and testers (centred here in Australia). It is not a commercial product: it is made by people with T1 diabetes for people with diabetes.

Anubis is the ancient Egyptian god of mummification and the afterlife, protector of the dead, as well as the patron god of lost souls and the helpless. He’s often depicted weighing the heart of the deceased against The Feather of Truth.

It seems a vaguely appropriate name.

Where to from here?

Each Anubis transmitter is produced from an expired/recycled Dexcom G6 Firefly. It gets physically modified and updated. It’s currently a small operation, and production at the moment is limited by the availability of expired transmitters. Pricing is unclear yet as it’s a fair bit of work, but should be no more than 50% the cost of a new Firefly. The expectation is not to make money out of this: everyone’s in it just to help other people with diabetes get access to featureful CGM.

Of course I plan to be reporting soon on my own Anubis experiences as part of the testing cohort.

Do you have expired G6 transmitters?

Making these units depends on the availability of expired Firefly G6s to recycle. If you have any, please don’t throw them out! I’m told people donating old transmitters should be prioritised as the production of Anubis units ramps up.

Collection points for expired Fireflies are currently established in five countries. Links (via Facebook) to these people are as follows:

Australia Simon
Netherlands Marvin
New Zealand Samuel
United Kingdom Matthew
United States Amanda

G6 Generations

Here’s a bit of a run-down of the history:

The original G6 transmitters had serial numbers that began with 80, and were basically a 2nd-generation G5. They didn’t need calibration and had 10-day sensor sessions, but otherwise they had the features of the G5. Including the ability to be reset via Bluetooth after replacing the battery. These have been quite sought-after in some circles because of their ability to be re-batteried.

Then a firmware change (apparently somewhere in the 81Cxxx range of serials) removed the ability to reset. This meant that after the first 100 days Native mode wasn’t available, and these transmitters were only useable with xDrip+, Spike, and xDrip4iOS (not with the Dexcom apps, Tandem pumps, etc). They can be re-batteried, but are then restricted in what they will work with.

Then came the “Firefly”. The serial numbers jumped up to 8Hxxxx or so, and the shape of the top of the units changed subtly. Internally the hardware underwent a major overhaul. The algorithm got some reworking too, especially the auto-calibration algorithm and sensor restart detection. Because Firefly removed the transmission of “raw” sensor data (which had been there since the G4) these transmitters would not work with Spike and xDrip4iOS, and as such could not be usefully re-batteried.

There have been continual Firefly firmware updates since, although the impact of each is much more subtle. When the G6 was introduced to Australia, we were well into the Firefly generation already.

South Africa seems to be the only place which receives the G6+ version, which otherwise seems to be similar to the Firefly.


There are signs of Dexcom’s next-generation G7 system emerging onto some international markets soon. Here in Australia the G6 was only introduced in 2020, but has not yet replaced the G5 for most people. I have no idea of when Dexcom might eventually bring the G7 to Australia. On a related note, it’s taken Abbott almost three years to bring the Libre 2 to Australia.

I think there’s plenty of life left in the G6 system all around the world.

19 thoughts on “Anubis – the G6 reborn!”

  1. Excellent overview. Thank you!

    With the reusable battery, I’m reading this as once we get one of these units we can reuse it and replace the battery ourselves when it runs out, is that right? Or does it have to be sent back to Simon and replaced again?

  2. I’m ecstatic at this news, and beyond grateful to all of the hard work and dedication of the amazing Easter Bionic Wookie and cohorts. Thank you so very much x

  3. Mic Priestley

    This is all just freakin’ amazing. I see that we are going to be able to replace the battery ourselves and glue it in. Does that mean that we can replace the battery more than once? ie Can one transmitter live forever with continuous battery replacement?
    Thank you so much to all of.the team working on this technology. You are true warriors.

    1. There would be some wear-n-tear so won’t last forever, but with care it should last a very long time. Especially as you should only have to replace the battery twice a year or so.

  4. Thanks so much. I am appalled at the greed in Dexcom, a thousand dollar transmitter with a non replaceable battery. I will support you best I can. Need G5 transmitters?

    1. The retail price of a G6 transmitter is AU$400. Not $1000, but still expensive when it only lasts 100 days.
      G5 transmitters are easily re-batteried and reset. The contacts I listed in various parts of the world are probably set up to handle those already, so sure they’re all useful thanks!

      1. Adrien de Croy

        Ability to source G4/G5 sensors on the other hand is not so straightforward, they are being forcefully phased out, and cannot be purchased in NZ any more unless you have some existing pump integration under warranty.

        A G6 transmitter here in NZ is $750 NZD or so. It’s outrageous we can’t change the $1.50 battery. I can’t imagine how it costs them more than $25 to make the transmitter either. They are just reaming us all, and escalating their anti-customer stance. They are going to be eaten alive by the Libre 2, because their policy is driving customers away.

        1. G5 is not being phased out in Australia yet, but G6 is starting to take hold so I guess it’s only a matter of time.

  5. What batterie are you using, with that mutch more power ? Is that a spezial one and will it be easy possible to get a new one, if needed ?

      1. Great, thanks for this information.
        Ever used Varta Lithium CR1632 in my, just died, 80xxx Transmitter.

        “Caro Go” is collecting a lot of expired old Fireflys in our community and will send them to marvin. 🙂

        1. Yes that’s probably what I would use in an 80xxxx too. There were some design changes with the Firefly.

  6. Hello!
    Is there a way to get one of the Anubis Transmitters???
    I am from germany and actually i have 8 used transmitters available.
    If you sent me your address i can ship these transmitters to Australia.
    Regards Rainer

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