Particle Device OS Updates Thread

Device OS 4.2.0 LTS is available in the Web IDE, Particle CLI and Workbench for (Argon/Boron/B SoM/B5 SoM/Tracker/E SoM X).

Released on September 26th, 2023

Note: This is a Release and may be used for production. This is the third Release in the Device OS release 4.x line (LTS) with critical bugfixes and backports from 5.x release line

To learn more about LTS release line, read our blog post.

You can view information about Device OS versions, upgrades and downgrades here.

Gen 3 256KB application binary support

Device OS v3.1.x and further releases bring support for 256KB application binaries to all Gen 3 platforms (at that time: Argon, Boron, B SoM, B5 SoM, Tracker). A few important aspects of this change:

  1. Compatibility with 128KB applications built with < Device OS 3.1 versions is maintained. Devices can still run them even if other parts have been upgraded to Device OS 3.1+.
  2. Upgrade process OTA (including product-based upgrades) is transparent.
  3. When upgrading locally (using DFU or Serial), make sure to update the bootloader first, as it has some logic managing compatibility between 128KB and 256KB application types. See this page on steps how to perform the update.
  4. If using standalone Particle CLI installation, make sure it's updated to >= 2.12.0 version, which includes support for 256KB applications.



  • [Cellular] Enables UPSV=1 low power mode for R510 when idle for >=9.2s #2674
  • [services] add long long support to printf/scanf #2694 #2696
  • [wiring] Add 64-bit String conversions #2693 #2657
  • [wiring] json: 64-bit support #2695 #2657


  • Fixes clean target for applications with large number of files + P2 PSRAM size calculation issues #2661
  • [gen3] hal: fixes the issue that UARTE RX may lose data #2698
  • [quectel] Fixes ncp-client not waiting for modem ready on cold boot #2700


  • [bootloader] remove nanopb dependency #2607
  • test] resolve sleep20 test failures. #2669
  • [nrf] Add Factory Reset Tests #2662
  • Update the key used for validating the ServerMoved signature #2688
  • [ci] fix macos builds #2683

System Binaries (all devices)

Programming and Debugging

You can view specific programming and debugging notes for this version of firmware here.

1 Like