The pin crosses libavr's phase-6 close and the guideline sweep behind it;
the example is byte-identical on both chips in both modes.
The port's own sweep found rule 36 in seven places, and the fix had to be
measured rather than applied. Sakamoto's month offsets as a `std::to_array`
local cost **+348 bytes** on a 1480-byte image - an automatic class-type
constant inside a `constexpr` function is given an address and built per
call, which outlined `weekday()` whole and pulled in `__do_copy_data` and
`__udivmodhi4`; `static constexpr` is what folds it, and emits no symbol at
all. The six register buffers cost +4 as `to_array`, which materialises its
argument array before copying where an aggregate initialiser stores each
element as it is computed - so those take CTAD, which counts the extent and
keeps the direct initialisation. Both spellings are rule 36; only one is
free.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The register sugar now rides the bus's own master role - device<Bus>
resolves avr::i2c::device<typename Bus::master, bus_address>, so a
consumer keeps handing over its declared dev::i2c<...> unchanged - and
the DS3231's hardwired 0x68 is a named constant. The example's four
discards became the LED's own error signal (a failed seed or a failed
alarm clear holds it dark, the same word a stuck bus says), the tree is
reformatted under InsertBraces, the sources are ASCII, and the README's
stale Studio byte counts are replaced by the claim its check-flags gate
holds.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Same driver surface as the yazoalfa version — clock and alarm get/set,
alarm interrupts, flag check/clear — plus oscillator-stop detection and
die temperature. One source for tiny85 (software I2C) and mega328P (TWI),
built against libavr in both generated and reflect mode, byte-identical
.text across modes. Errors surface as std::expected instead of being
dropped; weekday-rate alarms now really set the DY bit (legacy cleared
it); multi-register access is one coherent bus transaction. Legacy stays
on master.
Co-Authored-By: Claude <noreply@anthropic.com>
