Assets 11

Firmware 0.5.3-rc.2 Pre-release is out on the Build IDE for Core/Photon/P1/Electron

Note: This is a pre-release and is not intended for production yet. We've tested this pre-release to the best of our ability and we want to know what you think now! Please understand that some care and attention is necessary when testing this pre-release, and be sure to upgrade to the final release when it's available. It will not be available by default. To use you must select the version dropdown from the devices drawer. Downgrading back to the current release info is at the bottom of this post.
0 5 3-rc 2



  • DTR/RTS support (open/closed detection: Serial.isConnected()). #1073


  • [Electron] System firmware is now aware of system-part3 to allow OTA/YModem upgrade from >=0.5.3-rc.2 to >=0.6.0-rc.1


  • added HAL_IsISR() which is used to skip calling the background loop from delay(). fixes #673
  • Fixes an issue of USB Serial erroneously switching to closed state. #1073
  • RTC wakeup time now calculated right before entering SLEEP_MODE_DEEP. Fixes #1043
  • STOP mode should retain user interrupt handler. Fixes #1029

System Binaries (all devices) & Device Upgrader (Photon & Electron)

located below

Programming and Debugging

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