dramageek edited this page Aug 13, 2016 · 15 revisions

Welcome to MMeowlink

MMeowlink lets OpenAPS connect to Medtronic pumps without using the CareLink stick.

So what's that get us?

  1. MMeowlink gives us better range than the CareLink can provide. Our experience is that the device can cover a reasonably sized room when placed centrally.
  2. When placed under or next to a bed, there are no missing gaps in overnight OpenAPS coverage. You no longer need two CareLink sticks for coverage.
  3. Unlike the CareLink stick, the MMCommander sticks can be used with the Intel Edison. This allows us to replace the Raspberry Pi with the much smaller and lower power-consumption Edison.

MMeowlink currently supports the following drivers:


If you're new to OpenAPS, it's really probably best to stick with the Carelink stick to start. All of these options require quite a lot of fiddling around with electronics, firmware, and some are quite likely to even involve a soldering iron.

If you're based near other OpenAPS users that have gone through this process before, they may well be able to give you a hand. They may also be able to save you expensive purchases. Some of the items are only used once during this process. You should reach out on the Gitter chat group or on the OpenAPS mailing list for help. Some users may have modules with pre-built firmware available that they can send your way, which would dramatically reduce the complexity of this process.

Which option should I choose?

In all of the below cases, you want additional range, and are willing to trade range for some complex setup. There are a variety of cost options and size options that you can choose from.


In all cases below, you'll need access to a CC debugger or GoodFET. If all goes well, you'll only need this once or twice. This is when making contact with other OpenAPS users in your area is a good idea, since it's in the region of $50US.

Option 1: Pi or Edison with TI cc1111 stick

See TI-USB-Stick for instructions and details.

Recommended when:

  • You have a TI/mmcommander stick, or someone that can help you install subg_rfspy/mmcommander on one
  • You don't want to solder things
  • You don't want to fiddle with wires when trying to write the firmware to the hardware device
  • You want to reduce the size of your rig by using an Intel Edison (the carelink doesn't work with the Edison)

This is probably the easiest to get going with.

Note that I don't recommend the Pi Zero for this - as you only have one USB port on the Pi Zero, and it ends up being used by the TI stick and you then don't have Wifi access. You could use a two-port hub with this option and the Pi zero.

## Option 2: Edison with ERF radio

See Intel-Edison-with-ERF-XRF-stick for instructions and details.

Recommended when:

  • You want the smallest possible setup.
  • You are willing to pay for an Intel Edison (it costs a lot more than a Pi, and a lot lot more than a Pi zero).
  • You want to reduce battery size as much as possible.
  • You're willing to go through the complexity of installing an alternative Operating System on the Edison.
  • You're willing to solder things.
  • You're willing to fiddle with wires a lot to write the firmware.

This gets us the closest we've got to an 'ideal' low-size solution, but it takes a lot of work to reduce the size. It may be worth starting with one of the simpler and lower-cost options first. This will reduce the size of 1 (Pi or Edison with TI cc1111 stick) by about 50% if you use the Edison in both cases - but with approximately 10x the complexity.

Option 3: Pi Zero with ERF stick

NOTE Nobody's doing this yet - but Oskar is going to fill this bit of the wiki soon.

See Pi-Zero-with-ERF-stick for instructions and details.

Recommended when:

  • You want something that's reasonably low cost - and if it gets dropped in a puddle or crushed it won't break the bank.
  • You want something small, but don't necessarily want all the complexity of the Edison setup.
  • Are probably ok soldering 4 wires onto a Pi zero board

This is the simplest and most practical route, and should give you 3-4m range. Oskar is going to spend some time formalising this for people soon.

Option 4: Slice of Radio

Note The range of the Slice of Radio is currently un-tested. However https://www.wirelessthings.net/radio-comparison-chart shows that you should have radio transmission similar to the ERF stick, though perhaps a little less.

See Pi-With-Slice-of-Radio for instructions and details.

Recommended when:

  • You want something that doesn't require soldering
  • You're using an Raspberry Pi, rather than an Intel Edison, and are ok with a bigger device
  • You're looking for something cheaper than the TI stick
  • You're looking to make your Pi-based device smaller, by getting rid of the USB devices.

Option 5: Existing RileyLink hardware

Recommended when:

  • You have already bought a Rileylink and don't really want to buy extra things
  • You want good range and small size
  • You're willing to fiddle with wires and soldering to try and link things together
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