Back in June I started using an insulin pump, and very recently I began looping. Looping is connecting your insulin pump and continuous glucose monitoring (CGM) with software to automatically adjust your insulin levels as glucose levels change. Yep, I now trust a computer to finetune my insulin.

There were a couple of intermediate steps; I planned to write about this incrementally, but that didn’t happen so here’s a summary.


The main reason I did this was to solve a pain point – waking in the night with my blood glucose out of range, and having to fix it. This is not an infrequent occurrence, and it sucks. I have to wake up enough to do a bunch of arithmetic – how much insulin do I need? How much carbohydrate? Here’s the kind of data I’d be using:

Blood glucose records

Anything that reduces the frequency of this kind of interruption in life is welcome.

Sorting out continuous glucose monitoring (CGM)

First, I trialled a more mainstream form of CGM, the Dexcom system. I found its accuracy similar to my Freestyle Libre, while the software was very poor… someone online characterised the alarms as “absurdly insufficient”, which is entirely true: you can’t adjust anything.

So, back to the Libre. I was using my Libre with a Blucon transmitter which was kinda dodgy: physically awkward, disconnected quite often, and burned through a CR2032 battery every 3 days. I switched that for a MiaoMiao transmitter, which is super: it’s waterproof, way more reliable, and (so far?) I’ve only ripped it off once by accident.

I’m still experimenting with how best to attach the MiaoMiao. There’s a dearth of written information about this stuff, so I’ve had to listen to YouTube videos instead; Nerdabetic is my go-to source, and his post about Libre transmitters has been helpful. I’ve begun trying the wig adhesive he suggests, though it doesn’t seem as sticky as I had hoped…

Looping: hardware and software

RileyLink is the hardware that bridges everything: it uses radio comms to talk to the pump, and Bluetooth to talk to the phone (which itself is using Bluetooth to talk to the transmitter that sits on my sensor). Putting the RileyLink hardware together was all good; as ever, there’s a bias towards videos not textual information online, but the video I found was decent (links below).

Here’s its insides:

RileyLink circuitboard and battery

And here it is, ready to go:

RileyLink circuitboard and battery

In terms of software, setting up the Omnipod branch of Loop was fairly straightforward, although I had a bit of a faff integrating the code to use Spike (the software that talks to my Libre). It is so long since I’ve really played with code that things like dependency managers are unfamiliar to me :P A day home alone let me sort things out.

One further piece of the equation is Nightscout, a tool that allows access to glucose readings. The main use case seems to be for parents managing kids with type 1 diabetes, but for me there are 2 benefits:

  1. Have an eye on my glucose levels at my computer (the menubar widget is the best).
  2. Sweet reports. Want to check the min, max and standard deviation of your blood sugar per hour of the day? No problem!

I’m learning things daily. For example, occasionally the software isn’t sure if a bolus is delivered and flags this, but I’m still working out how to tell the system the insulin didn’t arrive if the bolus has failed. I think this has something to do with the integration with Apple Health…

Charge all the things!

I haven’t quite finished bundling together a single keyring with a cable for each item that needs charging: my phone, RileyLink, the MiaoMiao, and the Libre ‘reader’ (which I use fortnightly to initiate new sensors).

Here’s a “4 pin pogo magnetic charger” (?) for the MiaoMiao, a 3-in-one transmitter for my phone (lightning cable) and Libre (micro USB), plus an unneeded USB C cable :P Plus battery pack. I live in an earthquake zone. The mini USB cable (for RileyLink) is en route.

Bunch of cables

The feels and the community

Looping itself is awesome: on my first night I had a hypo and my low alarm woke me; I over-treated the low, but the technology worked to add a little insulin that kicked in just before my sugars were going to hit the point at which another alarm would wake me. It (obviously) doesn’t take away all the overheads of managing T1D, but it is a super valuable tool.

In the last four months I’ve made not one but two huge changes in how I manage my T1D: moving from multiple daily injections to a pump, then from normal pumping to looping. It’s fair to suggest that this kind of journey requires some space for emotions as well as technical implementation and straight-up learning.

I can’t close without adding two specific shoutouts, to Robert Bliss for general support and excellent knowledge of ISO standards, and Cal Young for all she has done on the Spike + Loop integration. The community as a whole is ace, and here are the links I mentioned:

The links, oh the links