> For the complete documentation index, see [llms.txt](https://docs.mtoolstec.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.mtoolstec.com/hardware/rfid-nfc-and-uhf-hardware/pn532killer/firmware-update.md).

# Update and Recover Firmware

Use an official firmware image matching the PN532Killer hardware revision. The device firmware is distributed as a `.bin`; the public host-code repository does not provide a complete reproducible device-firmware build project.

## Prepare

1. Download the matching image from the [official Firmware directory](https://github.com/NFC-funs/PN532Killer/tree/main/Firmware).
2. Export emulator data that you need to keep.
3. Use a direct USB connection and close other applications using the port.
4. Install the development CLI as described in [Connect and Scan](/hardware/rfid-nfc-and-uhf-hardware/pn532killer/quickstart.md).

## Update with PN532 CLI

At the interactive prompt:

```
hw connect -p COM3
hw version
hw fw --bin PN532Killer-firmware.bin
```

Replace the port and filename. The updater prompts for DFU entry: hold the device button, disconnect and reconnect USB while holding it, release the button, and confirm in the CLI. Follow the updater's prompts for the installed version.

The updater verifies written firmware before rebooting. Keep the device powered throughout erase, programming, and verification.

If the port changes on entering DFU, use the new path with the standalone utility when recovery is needed:

```bash
python script/dfu.py --port COM3 --bin PN532Killer-firmware.bin --force
```

`--force` expects manual DFU entry. It is a recovery option, not an alternative firmware-selection method.

## Verify

Reconnect after restart:

```
hw connect -p COM3
hw version
hw mode r
hf 14a scan
```

Restore slot data only after the device connects and scans correctly.

## Other Update Paths

The official Windows updater is available in [PcTools](https://github.com/NFC-funs/PN532Killer/tree/main/PcTools). MTools USB and MTools BLE do not update PN532Killer firmware.

If an update fails, retry DFU using the correct image and a stable USB connection. Boards without a button extension require their revision-specific DFU procedure; follow the board instructions instead of assuming contact locations.