flash-corne

name	flash-corne
description	Download the latest GitHub Actions firmware and flash the Corne keyboard halves over UF2 (nice!nano v2). Use when the user wants to update, flash, or reflash their Corne / ZMK firmware on macOS.

Flash Corne firmware

Automates fetching the latest CI firmware and copying it onto the nice!nano Corne halves. The only manual step is putting each half into bootloader mode — the host cannot trigger that remotely (a running ZMK board is just a USB HID device).

Helper script: .claude/skills/flash-corne/flash.sh (run via bash).

Procedure

1. Download the latest firmware Run bash .claude/skills/flash-corne/flash.sh download. Report the build (title + commit) it found so the user knows it's current.

2. Decide which halves to flash

   • Keymap / behavior / combo / .conf changes → usually only the left (central) half needs reflashing.
   • ZMK version bumps or split-config changes → flash both.
   • If unsure, ask. Default to left only for keymap edits.

3. Flash each half, one at a time For each half:

   • Tell the user: "Put the half into bootloader now — NAV layer + top outer corner (left corner = left half, right corner = right half), or double-tap the reset button."
   • Run bash .claude/skills/flash-corne/flash.sh flash <half> with run_in_background: true — the script polls with sleep, which is blocked when run in the foreground via the Bash tool. Read the task output file when it completes.
   • Report success/failure.

4. Verify (optional) ioreg -p IOUSB -l | grep '"USB Product Name" = "Corne"' confirms the half rebooted back into ZMK firmware (so it isn't bricked / still stuck in the bootloader).

Wiping BLE bonds (settings_reset)

Use this only when a profile slot is stuck — it advertises, the host sees it, and pairing fails every time no matter how often BT_CLR is pressed. That means Zephyr still holds a bond ZMK no longer tracks, and no in-keymap clear can reach it.

flash.sh flash reset writes the settings_reset firmware, which erases the settings partition on whichever half it lands on. The full cycle:

1. flash.sh flash reset on the left half, then again on the right half.
2. flash.sh flash left and flash.sh flash right to put the normal firmware back.
3. Re-pair every host. All profiles are empty now, and the halves re-bond to each other on their own.

While settings_reset is loaded the screen is dark and the radio is dead — the shield forces ZMK_BLE=n and ZMK_DISPLAY=n. That is expected, not a failed flash. Never stop after step 1.

Notes

• macOS cp prints could not copy extended attributes ... Device not configured — this is normal; only metadata fails, the firmware payload transfers fine. The script treats NICENANO unmounting as the success signal.
• Only the USB-connected half can enter the bootloader. To do both halves, flash one, then plug USB into / bootloader the other.
• Bootloader keys live on the NAV layer top outer corners (added to config/corne.keymap): left pinky-top = left half, right pinky-top = right half. They only work after the keymap that defines them has itself been flashed once.
• Repo override: set CORNE_REPO if the GitHub repo isn't mseok/zmk-config. Branch override: CORNE_BRANCH (default main) — needed to flash a build from a feature branch before it is merged. Wait override: WAIT_SECS.
• Direct use (no agent): the user can also just run bash .claude/skills/flash-corne/flash.sh both in a terminal and press the bootloader combo when prompted.