Connect a Pinecil
Choose USB for flashing or Bluetooth for telemetry and settings.
USB flashing
Use only the USB-C port, not the DC barrel jack. Hold [-] before plugging USB-C into the Pinecil, keep holding for 10-15 seconds, then release. A black screen means flash mode is ready for firmware or boot logo updates.
Bluetooth telemetry and settings
Bluetooth needs a Pinecil V2 on IronOS 2.21 or newer, powered normally instead of flash mode. On the iron, open Settings, find Bluetooth, and set it to + for full access. R is read-only, so telemetry works but setting writes are blocked.