IRQ logging revealed the tag IS responding (RX_SOF_DET set) but the
PN5180 cannot capture the 4-bit ACK as a complete frame — RX_IRQ
never fires and RX_STATUS stays zero. Skip per-page ACK checking
and rely on the read-back verification in ntag_write_pages().
The PN5180 transceive state machine wasn't being reset between the
SELECT (from reactivate_card) and the WRITE command — just re-setting
the TRANSCEIVE bits was a no-op. Use IDLE→TRANSCEIVE transition like
activate_type_a does. Also clear Crypto1 bit and add IRQ status
logging.
Temporary diagnostics to identify which step of the NTAG write
fails: per-page ACK status, reactivation, read-back, or data
mismatch. Enable DEBUG level for pn5180 module.
The NTAG WRITE ACK is 4 bits (0x0A), not a full byte. The PN5180
RX_STATUS register reports 0 complete bytes with 4 extra bits, but
the check only looked at the byte count — returning False on every
successful write. Check both byte and bit fields of RX_STATUS.
Also bump post-write delay from 5ms to 10ms for margin.
Three issues:
1. SAK gate too strict — NTAG chips can report SAK 0x04 (MIFARE
Ultralight family) instead of 0x00. Accept both in nfc_reader.py
and main.py.
2. TX CRC disabled for NTAG WRITE — the NTAG spec requires CRC on
the WRITE command frame. Enable TX CRC in ntag_write_page().
3. TX CRC disabled for NTAG READ — the post-write verification read
also failed because ntag_read_pages() sent the READ command
without CRC. Enable TX CRC there too.
Two issues:
1. SAK gate too strict — NTAG chips can report SAK 0x04 (MIFARE
Ultralight family) instead of 0x00. Accept both in nfc_reader.py
and main.py.
2. TX CRC disabled during WRITE — the NTAG WRITE command (0xA2)
requires a CRC on the frame. The PN5180 was sending without CRC,
causing the tag to NAK every write. Enable TX CRC for writes
(RX CRC stays off for the 4-bit ACK).
The NAU7802 ADC returns a stale max-scale value (0x7FFFFF) on its
first conversion after power-up, polluting the moving average and
making the initial weight report wildly inaccurate. Flush the first
reading during init().
Also extract both hardware drivers out of diagnostic scripts into
proper daemon modules:
- NAU7802 scale driver: scripts/scale_diag.py -> daemon/nau7802.py
- PN5180 NFC driver: scripts/read_tag.py -> daemon/pn5180.py
The production daemon was importing driver classes from test scripts
since the original SpoolBuddy commit. Diagnostic scripts now import
from the driver modules. Removed the sys.path hack from main.py.
maziggy