W000t, b4.0 is here! This is a major release that includes a TON of new features, stabilizations, upgrades, and more across the entire Meadow platform. Major highlights include:

  • WiFi Networking
  • Garbage Collector Tuning
  • Application Crash fix

Meadow.OS Improvements


Yaaaasss! WiFi networking is up! After nearly two years of engineering, Networking communications via WiFi are now available to Meadow apps.

File System Up

[you can now use the System.IO file system calls to work with the local file system]

Application Crash

The dreaded application crash that got introduced a few beta releases back that prevents Meadow applications from standing up for more than a few minutes has been fixed! [add details when avaialble]

Garbage Collector Tuning

The Mono garbage collector that we use in Meadow.OS got a major tune-up, making it much more suited for our architecture and use case. You should find that garbage collection works far better now than it did before.

Bug Fixes

Meadow.Core Improvements

Serial/UART Communications

We did a major overhaul of the UART/Serial Port in Meadow for b4.0. Big changes include:

  • Serial Port Events Fixed - Serial port events now work, which enables more efficient communications, without the need for a polling thread.
  • New ISerialMessagePort class - We fundamentally reworked the way legacy serial communications work, and created an ISerialMessagePort class that modernizes them. It’s thread-safe and asynchronous by default, and massively simplifies communications with serial devices by taking a message approach. We recommend using this class instead of ISerialPort for serial communications from now on.

For more info, check out the awesome Serial Communications Guide.

To see the new ISerialMessagePort class at work, check out the [GPS thingamajiggy when complete].

FilterableObserver Changes

We made some changes to the filterable observer:

  • Renamed FilterableObserver to FilterableChangeObserver. - We made this naming change because the FilterableObserver, as designed, was based on change notification and as such had Old and New values, along with built in comparison. However, it became clear that we should also have a non histrionic version for cases where Old and New had no meaning, so we also:
  • Created a new FilterableObserver class that doesn’t have histrionics. - Currently, the various Meadow.Core port classes used a standard IObservable<out T>, which was fine, but we wanted to extend the built-in filtering mechanism [TBD.]

Meadow.Core Samples

We completely re-did the old Meadow_Samples repo and renamed it to Meadow.Core.Samples. The samples are now much better organized and all updated to the latest .csproj format.


[12 new drivers!]

GPS Drivers


GPS/GNSS NMEA Processing

As part of our work to add GPS drivers, we completely re-worked, upgraded, and modernized the NMEA sentence parsing and decoding library. It now handles a wider array of sentence structures, is more fault tolerant, has a better API and is easier to add new decoders to.

Deployment & Tooling

New Meadow Library Templates

[adrian to add]

F# Meadow Templates

[adrian to add]

Other Stuff

Parametric Enclosure

Are you building a project and need an enclosure? We’ve created an easily modifiable enclosure template in Fusion 360 that allows you to change variables like length/depth/height, as well as the position of Meadow inside, and it’ll automatically resize for you:

You can use it as is, or use it as the starting point for more complicated enclosures by adding features.

Check it out at our 3D Print Designs repo.

Meadow EDA (Schematic and PCB Footprint) Parts

We’ve posted schematic symbols, PCB footprints, and 3D files of the Meadow F7 board for use in your own custom circuit designs. You can find them in our Meadow_EDA_Parts repo.


These docs are open source. If you find an issue, please file a bug, or send us a pull request. And if you want to contribute, we'd love that too!