Glastonbury 2022. A different kind of looping experience.

Two years after the last time I sat in a field for five days, listening to music, eating all sorts and enjoying cider, we were finally back. Back in the same field, similar cider and different music.

And this time a change to my looping approach. Around 18 months ago, I finally switched out of OpenAPS onto AndroidAPS, as the version had matched the OpenAPS version I’d been using for a number of years. So this time around, it was time for a different looping experience. Or perhaps more of the same. Who was to know?

Preparing for departure

As ever with travelling, or doing anything with Diabetes, when packing for the festival I take backups. I use a Roche Insight with AndroidAPS, and as you’d expect, had a spare in my kitbag. Historically when travelling or going to festivals, I’ve taken a couple of spare OpenAPS rigs and spare batteries, so instead I opted for a spare phone, going with a cheap Chinese phone (Xiaomi Note 10) with a large battery (5000mAh), running Android 11.

If I’d thought about it a little more, I’d have loaded up all the apps required while at home and checked they all worked, however I missed a trick with that, instead loading the required install files to the cloud.

Additionally, as ever with festivals, where access to power can be a challenge, there were also a multitude of power packs to charge, in the hope of keeping phones and watches alive during the five days in the field.

Before heading to the festival, I was aware that my now 14 month old Samsung was starting to suffer a bit on battery longevity, and to add to the issues, the morning we were due to leave for the festival, I managed to drop it down the stairs.

While I’m aware that this isn’t all that clever, an initial inspection suggested that it was fine, and the Dexcom had a further 4 days left on it and required a transmitter change. Rather than switch to the backup there and then, I decided to leave it and if required, change to the backup phone when the Dexcom needed swapping. There didn’t seem to be a need for a large amount of extra prep on behalf of the AID system.

In the field…

It only became apparent that perhaps my decisions pre- departure might have been sub-optimal the morning after arrival.

As ever, overnight, I put the phone on charge using one of the power blocks that we’d brought with us, and the “fast charge” socket. When I awoke the next day, there was clearly an issue with charging. The phone had charged a bit but was nowhere near full.

After some fiddling with the USB-C port, it became apparent very quickly that the drop down the stairs had done some sort of damage to the charging socket, and that it had become temperamental. The plug no longer locked in place and I’d get strange “slow charging” messages.

It’s at times like these that you have to make choices. Fully aware that my phone was not now functioning correctly, knowing that the battery life might not be the best and that I probably would have issues charging it, it would probably have made sense to switch the Dexcom and AAPS to the new phone. Instead I chose to keep going on the phone I knew had issues because I wanted to eak the days out of the very expensive Dexcom and wasn’t sure that I’d get one more start out of it when swapping to a new phone.

That turned out to be the wrong decision, as overnight the next night, the phone didn’t charge at all, and I lost AAPS and CGM. Did anything bad happen? Who knows. Exhaustion set in and I woke up the following morning at 7mmol/l. I assume that everything worked fine.

So it got switched out, the new phone was set up, and we had trouble free looping for the rest of the festival. And using the new phone with nothing else on it and all data services switched off revealed just how much of a drain those put on the battery. Without them, running AAPS and xDrip, the system used ~15% of the battery per day. Around 7 days battery life. Another useful piece of information.

Thanks for the diatribe on hardware issues. What about the looping experience?

Using AndroidAPS compared to OpenAPS is different, but it depends on how you use it as to whether that is vastly different. For me old habits die hard, and I mostly don’t enter carbs. On this occasion I was using my Boost variant, which also meant less intervention to deal with bolusing.

AAPS (just) on a very sunny phone…

I opted for a bolusing a bit for meals, as when doing as much walking as you do at something like Glastonbury, the fact that it was pretty warm, and given the state of toilets, it seemed better to avoid higher postprandial glucose levels, dehydration and a need to find a loo too frequently. 

With one overnight hypo caused by a user error when my Boost code wasn’t active (not thinking about IOB when I bolused before bed for food that was eaten late and probably should have been left), the Time in Range for Glastonbury was just below 83%. In fact, compared to 2019, the hypo count was lower and overall TIR was higher.

If we ignore that one overnight period, then TIR would have been 85% and Time Below Range would have been 5%, which for a festival involving a lot of walking and plenty of alcohol, is very acceptable.

The reality was that the looping experience for me wasn’t very different to the last few occasions. I tend to bolus from the pump as much as pulling the phone out, because if you’re not entering carbs or using a bolus wizard, the phone is just an unnecessary interface.

AAPS in my Boost guise worked very well with partial meal bolusing.

Get your sensors out!

One of he main benefits of the roll out of Libre on the NHS has been the increase in visibility of fellow diabetics, and this was never more obvious than at Glastonbury where you have 200,000 people in a range of fields.

With the weather being mostly fine and T-Shirts de rigeur, the approximately 1,270 people with type 1 that might have been at Glastonbury were much easier to spot, and indeed, it was easy to mooch up and have a friendly chat. All helped by Este Haim mentioning her hypo in the wings on their first appearance at the festival.

If there’s one thing that greater sensor wear provides, it’s easier peer support when people want it, which can only be a good thing!

Any takeaways?

As always, with five days in a field, there are takeaways.

  1. Don’t go away with a phone that may not be functioning properly when you’re an AAPS user, even if the Dexcom has a number of days left. It generally won’t end well.
  2. Take devices, other devices and other, other devices. You don’t want things going wrong and having no alternative.
  3. Boost worked much better than I expected at a festival!
  4. Human intervention is the best way to get bad results. Especially tired or impaired human intervention.
  5. Visible sensors are a great way to meet people.
  6. Choosing the best way to use a phone based loop is challenging. Anything that saves battery life is helpful, but carrying multiple devices may not be.

It sounds trite, but the best way to get your AAPS phone to last is to use it as a dedicated device. As I mentioned earlier, running a phone as an AAPS device with limited data connectivity provides vastly superior battery life when compared to using it as a phone and internet terminal.

And therein presents the challenge. Whether it’s CamAPS, AAPS, or Loop, the idea of having your AID system as an app is appealing because it reduces what you have to carry about and is easily accessible. But at the same time, it instantly affects a bunch of other things, notably device battery longevity and what happens when things break?

We can each make our own choices on what’s important to us, but if battery life is one of those, an independent device is surely the winner.


  1. Great read – I’m packing for a trip to the US and this post is timely. I hope you enjoyed the festival

  2. Thanks for this nice report! I hope you had a great time despite of all these issues! I think everyone of us using loop systems knows what you’re talking about pretty well! ? And we all make these “mistakes” of doing things like “I should change the sensor before, but…. Come on… Give it a try, I can do this later”… And actually we, at least I, do it repeatedly in different occasions ???. It is like a small battle my diabetes and its setup against me and my stubbornness ?.

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