> For the complete documentation index, see [llms.txt](https://support.keyst.one/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://support.keyst.one/changelog/keystone-firmware-btc-only/firmware-upgrade-v-1.1.1.md).

# V 1.1.1 (BTC-Only)

BTC-Only firmware V1.1.1 includes the updates below：

    1\. New QR code formatting.

    2\. Support formatting microSD card to FAT32.

    3\. Single signature PSBT compatibility with Sparrow Wallet.