---
title: K2 firmware 3.1 release notes
version: 2
status: current
date: 2025-01-20
supersedes: firmware-3.1-notes-v1.md
---

# K2 firmware 3.1

Firmware 3.1 adds Bluetooth pairing with the Quillmere mobile app and fixes a calibration
drift that affected readings above 1,500 ppm.

## Defaults

- Default sample interval: 5 seconds
- Display timeout: 60 seconds
- Bluetooth: off until paired

## Upgrading

Connect the meter by USB-C and run the updater. The upgrade takes about four minutes and
keeps all stored readings.